Merge pull request #6824 from yyforyongyu/5-new-itest

itest: continued itest refactor and fix - IV

docs/release-notes/release-notes-0.16.0.md

@@ -369,7 +369,8 @@ PRs([6776](https://github.com/lightningnetwork/lnd/pull/6776),
 [7172](https://github.com/lightningnetwork/lnd/pull/7172),
 [7242](https://github.com/lightningnetwork/lnd/pull/7242),
 [7245](https://github.com/lightningnetwork/lnd/pull/7245)),
-[6823](https://github.com/lightningnetwork/lnd/pull/6823)) have been made to
+[6823](https://github.com/lightningnetwork/lnd/pull/6823),
+[6824](https://github.com/lightningnetwork/lnd/pull/6824),) have been made to
 refactor the itest for code health and maintenance.
 
 # Contributors (Alphabetical Order)

lntemp/harness.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/hex"
 	"fmt"
-	"sync"
 	"testing"
 	"time"
 
@@ -676,6 +675,32 @@ func (h *HarnessTest) NewNodeWithSeedEtcd(name string, etcdCfg *etcd.Config,
 	return h.newNodeWithSeed(name, extraArgs, req, statelessInit)
 }
 
+// NewNodeRemoteSigner creates a new remote signer node and asserts its
+// creation.
+func (h *HarnessTest) NewNodeRemoteSigner(name string, extraArgs []string,
+	password []byte, watchOnly *lnrpc.WatchOnly) *node.HarnessNode {
+
+	hn, err := h.manager.newNode(h.T, name, extraArgs, password, true)
+	require.NoErrorf(h, err, "unable to create new node for %s", name)
+
+	err = hn.StartWithNoAuth(h.runCtx)
+	require.NoError(h, err, "failed to start node %s", name)
+
+	// With the seed created, construct the init request to the node,
+	// including the newly generated seed.
+	initReq := &lnrpc.InitWalletRequest{
+		WalletPassword: password,
+		WatchOnly:      watchOnly,
+	}
+
+	// Pass the init request via rpc to finish unlocking the node. This
+	// will also initialize the macaroon-authenticated LightningClient.
+	_, err = h.manager.initWalletAndNode(hn, initReq)
+	require.NoErrorf(h, err, "failed to init node %s", name)
+
+	return hn
+}
+
 // KillNode kills the node (but won't wait for the node process to stop).
 func (h *HarnessTest) KillNode(hn *node.HarnessNode) {
 	require.NoErrorf(h, hn.Kill(), "%s: kill got error", hn.Name())
@@ -797,6 +822,26 @@ type OpenChannelParams struct {
 	// ScidAlias denotes whether the channel will be an option-scid-alias
 	// channel type negotiation.
 	ScidAlias bool
+
+	// BaseFee is the channel base fee applied during the channel
+	// announcement phase.
+	BaseFee uint64
+
+	// FeeRate is the channel fee rate in ppm applied during the channel
+	// announcement phase.
+	FeeRate uint64
+
+	// UseBaseFee, if set, instructs the downstream logic to apply the
+	// user-specified channel base fee to the channel update announcement.
+	// If set to false it avoids applying a base fee of 0 and instead
+	// activates the default configured base fee.
+	UseBaseFee bool
+
+	// UseFeeRate, if set, instructs the downstream logic to apply the
+	// user-specified channel fee rate to the channel update announcement.
+	// If set to false it avoids applying a fee rate of 0 and instead
+	// activates the default configured fee rate.
+	UseFeeRate bool
 }
 
 // prepareOpenChannel waits for both nodes to be synced to chain and returns an
@@ -833,6 +878,10 @@ func (h *HarnessTest) prepareOpenChannel(srcNode, destNode *node.HarnessNode,
 		CommitmentType:     p.CommitmentType,
 		ZeroConf:           p.ZeroConf,
 		ScidAlias:          p.ScidAlias,
+		BaseFee:            p.BaseFee,
+		FeeRate:            p.FeeRate,
+		UseBaseFee:         p.UseBaseFee,
+		UseFeeRate:         p.UseFeeRate,
 	}
 }
 
@@ -886,24 +935,76 @@ func (h *HarnessTest) OpenChannelAssertStream(srcNode,
 }
 
 // OpenChannel attempts to open a channel with the specified parameters
-// extended from Alice to Bob. Additionally, the following items are asserted,
-//   - 6 blocks will be mined so the channel will be announced if it's public.
-//   - the funding transaction should be found in the first block.
+// extended from Alice to Bob. Additionally, for public channels, it will mine
+// extra blocks so they are announced to the network. In specific, the
+// following items are asserted,
+//   - for non-zero conf channel, 1 blocks will be mined to confirm the funding
+//     tx.
 //   - both nodes should see the channel edge update in their network graph.
 //   - both nodes can report the status of the new channel from ListChannels.
+//   - extra blocks are mined if it's a public channel.
 func (h *HarnessTest) OpenChannel(alice, bob *node.HarnessNode,
 	p OpenChannelParams) *lnrpc.ChannelPoint {
 
+	// First, open the channel without announcing it.
+	cp := h.OpenChannelNoAnnounce(alice, bob, p)
+
+	// If this is a private channel, there's no need to mine extra blocks
+	// since it will never be announced to the network.
+	if p.Private {
+		return cp
+	}
+
+	// Mine extra blocks to announce the channel.
+	if p.ZeroConf {
+		// For a zero-conf channel, no blocks have been mined so we
+		// need to mine 6 blocks.
+		//
+		// Mine 1 block to confirm the funding transaction.
+		h.MineBlocksAndAssertNumTxes(numBlocksOpenChannel, 1)
+	} else {
+		// For a regular channel, 1 block has already been mined to
+		// confirm the funding transaction, so we mine 5 blocks.
+		h.MineBlocks(numBlocksOpenChannel - 1)
+	}
+
+	return cp
+}
+
+// OpenChannelNoAnnounce attempts to open a channel with the specified
+// parameters extended from Alice to Bob without mining the necessary blocks to
+// announce the channel. Additionally, the following items are asserted,
+//   - for non-zero conf channel, 1 blocks will be mined to confirm the funding
+//     tx.
+//   - both nodes should see the channel edge update in their network graph.
+//   - both nodes can report the status of the new channel from ListChannels.
+func (h *HarnessTest) OpenChannelNoAnnounce(alice, bob *node.HarnessNode,
+	p OpenChannelParams) *lnrpc.ChannelPoint {
+
 	chanOpenUpdate := h.OpenChannelAssertStream(alice, bob, p)
 
-	// Mine 6 blocks, then wait for Alice's node to notify us that the
-	// channel has been opened. The funding transaction should be found
-	// within the first newly mined block. We mine 6 blocks so that in the
-	// case that the channel is public, it is announced to the network.
-	block := h.MineBlocksAndAssertNumTxes(numBlocksOpenChannel, 1)[0]
+	// Open a zero conf channel.
+	if p.ZeroConf {
+		return h.openChannelZeroConf(alice, bob, chanOpenUpdate)
+	}
+
+	// Open a non-zero conf channel.
+	return h.openChannel(alice, bob, chanOpenUpdate)
+}
+
+// openChannel attempts to open a channel with the specified parameters
+// extended from Alice to Bob. Additionally, the following items are asserted,
+//   - 1 block is mined and the funding transaction should be found in it.
+//   - both nodes should see the channel edge update in their network graph.
+//   - both nodes can report the status of the new channel from ListChannels.
+func (h *HarnessTest) openChannel(alice, bob *node.HarnessNode,
+	stream rpc.OpenChanClient) *lnrpc.ChannelPoint {
+
+	// Mine 1 block to confirm the funding transaction.
+	block := h.MineBlocksAndAssertNumTxes(1, 1)[0]
 
 	// Wait for the channel open event.
-	fundingChanPoint := h.WaitForChannelOpenEvent(chanOpenUpdate)
+	fundingChanPoint := h.WaitForChannelOpenEvent(stream)
 
 	// Check that the funding tx is found in the first block.
 	fundingTxID := h.GetChanPointFundingTxid(fundingChanPoint)
@@ -918,9 +1019,27 @@ func (h *HarnessTest) OpenChannel(alice, bob *node.HarnessNode,
 	h.AssertChannelExists(alice, fundingChanPoint)
 	h.AssertChannelExists(bob, fundingChanPoint)
 
-	// Finally, check the blocks are synced.
-	h.WaitForBlockchainSync(alice)
-	h.WaitForBlockchainSync(bob)
+	return fundingChanPoint
+}
+
+// openChannelZeroConf attempts to open a channel with the specified parameters
+// extended from Alice to Bob. Additionally, the following items are asserted,
+//   - both nodes should see the channel edge update in their network graph.
+//   - both nodes can report the status of the new channel from ListChannels.
+func (h *HarnessTest) openChannelZeroConf(alice, bob *node.HarnessNode,
+	stream rpc.OpenChanClient) *lnrpc.ChannelPoint {
+
+	// Wait for the channel open event.
+	fundingChanPoint := h.WaitForChannelOpenEvent(stream)
+
+	// Check that both alice and bob have seen the channel from their
+	// network topology.
+	h.AssertTopologyChannelOpen(alice, fundingChanPoint)
+	h.AssertTopologyChannelOpen(bob, fundingChanPoint)
+
+	// Finally, check that the channel can be seen in their ListChannels.
+	h.AssertChannelExists(alice, fundingChanPoint)
+	h.AssertChannelExists(bob, fundingChanPoint)
 
 	return fundingChanPoint
 }
@@ -1145,36 +1264,54 @@ func (h *HarnessTest) FundCoinsP2TR(amt btcutil.Amount,
 	h.fundCoins(amt, target, lnrpc.AddressType_TAPROOT_PUBKEY, true)
 }
 
-// CompletePaymentRequests sends payments from a node to complete all payment
-// requests. This function does not return until all payments successfully
-// complete without errors.
-func (h *HarnessTest) CompletePaymentRequests(hn *node.HarnessNode,
-	paymentRequests []string) {
+// completePaymentRequestsAssertStatus sends payments from a node to complete
+// all payment requests. This function does not return until all payments
+// have reached the specified status.
+func (h *HarnessTest) completePaymentRequestsAssertStatus(hn *node.HarnessNode,
+	paymentRequests []string, status lnrpc.Payment_PaymentStatus) {
 
-	var wg sync.WaitGroup
+	// Create a buffered chan to signal the results.
+	results := make(chan rpc.PaymentClient, len(paymentRequests))
 
 	// send sends a payment and asserts if it doesn't succeeded.
 	send := func(payReq string) {
-		defer wg.Done()
-
 		req := &routerrpc.SendPaymentRequest{
 			PaymentRequest: payReq,
 			TimeoutSeconds: defaultPaymentTimeout,
 			FeeLimitMsat:   noFeeLimitMsat,
 		}
 		stream := hn.RPC.SendPayment(req)
-		h.AssertPaymentStatusFromStream(stream, lnrpc.Payment_SUCCEEDED)
+
+		// Signal sent succeeded.
+		results <- stream
 	}
 
 	// Launch all payments simultaneously.
 	for _, payReq := range paymentRequests {
 		payReqCopy := payReq
-		wg.Add(1)
 		go send(payReqCopy)
 	}
 
-	// Wait for all payments to report success.
-	wg.Wait()
+	// Wait for all payments to report the expected status.
+	timer := time.After(DefaultTimeout)
+	select {
+	case stream := <-results:
+		h.AssertPaymentStatusFromStream(stream, status)
+
+	case <-timer:
+		require.Fail(h, "timeout", "waiting payment results timeout")
+	}
+}
+
+// CompletePaymentRequests sends payments from a node to complete all payment
+// requests. This function does not return until all payments successfully
+// complete without errors.
+func (h *HarnessTest) CompletePaymentRequests(hn *node.HarnessNode,
+	paymentRequests []string) {
+
+	h.completePaymentRequestsAssertStatus(
+		hn, paymentRequests, lnrpc.Payment_SUCCEEDED,
+	)
 }
 
 // CompletePaymentRequestsNoWait sends payments from a node to complete all
@@ -1188,21 +1325,10 @@ func (h *HarnessTest) CompletePaymentRequestsNoWait(hn *node.HarnessNode,
 	// we return.
 	oldResp := h.GetChannelByChanPoint(hn, chanPoint)
 
-	// send sends a payment and asserts if it doesn't succeeded.
-	send := func(payReq string) {
-		req := &routerrpc.SendPaymentRequest{
-			PaymentRequest: payReq,
-			TimeoutSeconds: defaultPaymentTimeout,
-			FeeLimitMsat:   noFeeLimitMsat,
-		}
-		hn.RPC.SendPayment(req)
-	}
-
-	// Launch all payments simultaneously.
-	for _, payReq := range paymentRequests {
-		payReqCopy := payReq
-		go send(payReqCopy)
-	}
+	// Send payments and assert they are in-flight.
+	h.completePaymentRequestsAssertStatus(
+		hn, paymentRequests, lnrpc.Payment_IN_FLIGHT,
+	)
 
 	// We are not waiting for feedback in the form of a response, but we
 	// should still wait long enough for the server to receive and handle
@@ -1797,3 +1923,92 @@ func (h *HarnessTest) QueryRoutesAndRetry(hn *node.HarnessNode,
 
 	return routes
 }
+
+// ReceiveHtlcInterceptor waits until a message is received on the htlc
+// interceptor stream or the timeout is reached.
+func (h *HarnessTest) ReceiveHtlcInterceptor(
+	stream rpc.InterceptorClient) *routerrpc.ForwardHtlcInterceptRequest {
+
+	chanMsg := make(chan *routerrpc.ForwardHtlcInterceptRequest)
+	errChan := make(chan error)
+	go func() {
+		// Consume one message. This will block until the message is
+		// received.
+		resp, err := stream.Recv()
+		if err != nil {
+			errChan <- err
+			return
+		}
+		chanMsg <- resp
+	}()
+
+	select {
+	case <-time.After(DefaultTimeout):
+		require.Fail(h, "timeout", "timeout intercepting htlc")
+
+	case err := <-errChan:
+		require.Failf(h, "err from stream",
+			"received err from stream: %v", err)
+
+	case updateMsg := <-chanMsg:
+		return updateMsg
+	}
+
+	return nil
+}
+
+// ReceiveChannelEvent waits until a message is received from the
+// ChannelEventsClient stream or the timeout is reached.
+func (h *HarnessTest) ReceiveChannelEvent(
+	stream rpc.ChannelEventsClient) *lnrpc.ChannelEventUpdate {
+
+	chanMsg := make(chan *lnrpc.ChannelEventUpdate)
+	errChan := make(chan error)
+	go func() {
+		// Consume one message. This will block until the message is
+		// received.
+		resp, err := stream.Recv()
+		if err != nil {
+			errChan <- err
+			return
+		}
+		chanMsg <- resp
+	}()
+
+	select {
+	case <-time.After(DefaultTimeout):
+		require.Fail(h, "timeout", "timeout intercepting htlc")
+
+	case err := <-errChan:
+		require.Failf(h, "err from stream",
+			"received err from stream: %v", err)
+
+	case updateMsg := <-chanMsg:
+		return updateMsg
+	}
+
+	return nil
+}
+
+// GetOutputIndex returns the output index of the given address in the given
+// transaction.
+func (h *HarnessTest) GetOutputIndex(txid *chainhash.Hash, addr string) int {
+	// We'll then extract the raw transaction from the mempool in order to
+	// determine the index of the p2tr output.
+	tx := h.Miner.GetRawTransaction(txid)
+
+	p2trOutputIndex := -1
+	for i, txOut := range tx.MsgTx().TxOut {
+		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+			txOut.PkScript, h.Miner.ActiveNet,
+		)
+		require.NoError(h, err)
+
+		if addrs[0].String() == addr {
+			p2trOutputIndex = i
+		}
+	}
+	require.Greater(h, p2trOutputIndex, -1)
+
+	return p2trOutputIndex
+}

lntemp/harness_assertion.go

@@ -1,12 +1,14 @@
 package lntemp
 
 import (
+	"bytes"
 	"context"
 	"crypto/rand"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"math"
+	"sort"
 	"strings"
 	"time"
 
@@ -127,6 +129,9 @@ func (h *HarnessTest) ConnectNodesPerm(a, b *node.HarnessNode) {
 func (h *HarnessTest) DisconnectNodes(a, b *node.HarnessNode) {
 	bobInfo := b.RPC.GetInfo()
 	a.RPC.DisconnectPeer(bobInfo.IdentityPubkey)
+
+	// Assert disconnected.
+	h.AssertPeerNotConnected(a, b)
 }
 
 // EnsureConnected will try to connect to two nodes, returning no error if they
@@ -729,6 +734,51 @@ func (h *HarnessTest) AssertNumUTXOs(hn *node.HarnessNode,
 	return h.AssertNumUTXOsWithConf(hn, num, math.MaxInt32, 0)
 }
 
+// getUTXOs gets the number of newly created UTOXs within the current test
+// scope.
+func (h *HarnessTest) getUTXOs(hn *node.HarnessNode, account string,
+	max, min int32) []*lnrpc.Utxo {
+
+	var unconfirmed bool
+
+	if max == 0 {
+		unconfirmed = true
+	}
+
+	req := &walletrpc.ListUnspentRequest{
+		Account:         account,
+		MaxConfs:        max,
+		MinConfs:        min,
+		UnconfirmedOnly: unconfirmed,
+	}
+	resp := hn.RPC.ListUnspent(req)
+
+	return resp.Utxos
+}
+
+// GetUTXOs returns all the UTXOs for the given node's account, including
+// confirmed and unconfirmed.
+func (h *HarnessTest) GetUTXOs(hn *node.HarnessNode,
+	account string) []*lnrpc.Utxo {
+
+	return h.getUTXOs(hn, account, math.MaxInt32, 0)
+}
+
+// GetUTXOsConfirmed returns the confirmed UTXOs for the given node's account.
+func (h *HarnessTest) GetUTXOsConfirmed(hn *node.HarnessNode,
+	account string) []*lnrpc.Utxo {
+
+	return h.getUTXOs(hn, account, math.MaxInt32, 1)
+}
+
+// GetUTXOsUnconfirmed returns the unconfirmed UTXOs for the given node's
+// account.
+func (h *HarnessTest) GetUTXOsUnconfirmed(hn *node.HarnessNode,
+	account string) []*lnrpc.Utxo {
+
+	return h.getUTXOs(hn, account, 0, 0)
+}
+
 // WaitForBalanceConfirmed waits until the node sees the expected confirmed
 // balance in its wallet.
 func (h *HarnessTest) WaitForBalanceConfirmed(hn *node.HarnessNode,
@@ -878,6 +928,16 @@ func (h *HarnessTest) AssertPaymentStatusFromStream(stream rpc.PaymentClient,
 	return h.assertPaymentStatusWithTimeout(stream, status, DefaultTimeout)
 }
 
+// AssertPaymentSucceedWithTimeout asserts that a payment is succeeded within
+// the specified timeout.
+func (h *HarnessTest) AssertPaymentSucceedWithTimeout(stream rpc.PaymentClient,
+	timeout time.Duration) *lnrpc.Payment {
+
+	return h.assertPaymentStatusWithTimeout(
+		stream, lnrpc.Payment_SUCCEEDED, timeout,
+	)
+}
+
 // assertPaymentStatusWithTimeout takes a client stream and asserts the payment
 // is in desired status before the specified timeout. The payment found is
 // returned once succeeded.
@@ -889,7 +949,9 @@ func (h *HarnessTest) assertPaymentStatusWithTimeout(stream rpc.PaymentClient,
 	err := wait.NoError(func() error {
 		// Consume one message. This will raise an error if the message
 		// is not received within DefaultTimeout.
-		payment, err := h.ReceivePaymentUpdate(stream)
+		payment, err := h.receivePaymentUpdateWithTimeout(
+			stream, timeout,
+		)
 		if err != nil {
 			return fmt.Errorf("received error from payment "+
 				"stream: %s", err)
@@ -918,8 +980,17 @@ func (h *HarnessTest) assertPaymentStatusWithTimeout(stream rpc.PaymentClient,
 func (h *HarnessTest) ReceivePaymentUpdate(
 	stream rpc.PaymentClient) (*lnrpc.Payment, error) {
 
+	return h.receivePaymentUpdateWithTimeout(stream, DefaultTimeout)
+}
+
+// receivePaymentUpdateWithTimeout waits until a message is received on the
+// payment client stream or the timeout is reached.
+func (h *HarnessTest) receivePaymentUpdateWithTimeout(stream rpc.PaymentClient,
+	timeout time.Duration) (*lnrpc.Payment, error) {
+
 	chanMsg := make(chan *lnrpc.Payment, 1)
 	errChan := make(chan error, 1)
+
 	go func() {
 		// Consume one message. This will block until the message is
 		// received.
@@ -933,7 +1004,7 @@ func (h *HarnessTest) ReceivePaymentUpdate(
 	}()
 
 	select {
-	case <-time.After(DefaultTimeout):
+	case <-time.After(timeout):
 		require.Fail(h, "timeout", "timeout waiting for payment update")
 		return nil, nil
 
@@ -2074,3 +2145,145 @@ func (h *HarnessTest) ReceiveSendToRouteUpdate(
 		return updateMsg, nil
 	}
 }
+
+// AssertInvoiceEqual asserts that two lnrpc.Invoices are equivalent. A custom
+// comparison function is defined for these tests, since proto message returned
+// from unary and streaming RPCs (as of protobuf 1.23.0 and grpc 1.29.1) aren't
+// consistent with the private fields set on the messages. As a result, we
+// avoid using require.Equal and test only the actual data members.
+func (h *HarnessTest) AssertInvoiceEqual(a, b *lnrpc.Invoice) {
+	// Ensure the HTLCs are sorted properly before attempting to compare.
+	sort.Slice(a.Htlcs, func(i, j int) bool {
+		return a.Htlcs[i].ChanId < a.Htlcs[j].ChanId
+	})
+	sort.Slice(b.Htlcs, func(i, j int) bool {
+		return b.Htlcs[i].ChanId < b.Htlcs[j].ChanId
+	})
+
+	require.Equal(h, a.Memo, b.Memo)
+	require.Equal(h, a.RPreimage, b.RPreimage)
+	require.Equal(h, a.RHash, b.RHash)
+	require.Equal(h, a.Value, b.Value)
+	require.Equal(h, a.ValueMsat, b.ValueMsat)
+	require.Equal(h, a.CreationDate, b.CreationDate)
+	require.Equal(h, a.SettleDate, b.SettleDate)
+	require.Equal(h, a.PaymentRequest, b.PaymentRequest)
+	require.Equal(h, a.DescriptionHash, b.DescriptionHash)
+	require.Equal(h, a.Expiry, b.Expiry)
+	require.Equal(h, a.FallbackAddr, b.FallbackAddr)
+	require.Equal(h, a.CltvExpiry, b.CltvExpiry)
+	require.Equal(h, a.RouteHints, b.RouteHints)
+	require.Equal(h, a.Private, b.Private)
+	require.Equal(h, a.AddIndex, b.AddIndex)
+	require.Equal(h, a.SettleIndex, b.SettleIndex)
+	require.Equal(h, a.AmtPaidSat, b.AmtPaidSat)
+	require.Equal(h, a.AmtPaidMsat, b.AmtPaidMsat)
+	require.Equal(h, a.State, b.State)
+	require.Equal(h, a.Features, b.Features)
+	require.Equal(h, a.IsKeysend, b.IsKeysend)
+	require.Equal(h, a.PaymentAddr, b.PaymentAddr)
+	require.Equal(h, a.IsAmp, b.IsAmp)
+
+	require.Equal(h, len(a.Htlcs), len(b.Htlcs))
+	for i := range a.Htlcs {
+		htlcA, htlcB := a.Htlcs[i], b.Htlcs[i]
+		require.Equal(h, htlcA.ChanId, htlcB.ChanId)
+		require.Equal(h, htlcA.HtlcIndex, htlcB.HtlcIndex)
+		require.Equal(h, htlcA.AmtMsat, htlcB.AmtMsat)
+		require.Equal(h, htlcA.AcceptHeight, htlcB.AcceptHeight)
+		require.Equal(h, htlcA.AcceptTime, htlcB.AcceptTime)
+		require.Equal(h, htlcA.ResolveTime, htlcB.ResolveTime)
+		require.Equal(h, htlcA.ExpiryHeight, htlcB.ExpiryHeight)
+		require.Equal(h, htlcA.State, htlcB.State)
+		require.Equal(h, htlcA.CustomRecords, htlcB.CustomRecords)
+		require.Equal(h, htlcA.MppTotalAmtMsat, htlcB.MppTotalAmtMsat)
+		require.Equal(h, htlcA.Amp, htlcB.Amp)
+	}
+}
+
+// AssertUTXOInWallet asserts that a given UTXO can be found in the node's
+// wallet.
+func (h *HarnessTest) AssertUTXOInWallet(hn *node.HarnessNode,
+	op *lnrpc.OutPoint, account string) {
+
+	err := wait.NoError(func() error {
+		utxos := h.GetUTXOs(hn, account)
+
+		err := fmt.Errorf("tx with hash %x not found", op.TxidBytes)
+		for _, utxo := range utxos {
+			if !bytes.Equal(utxo.Outpoint.TxidBytes, op.TxidBytes) {
+				continue
+			}
+
+			err = fmt.Errorf("tx with output index %v not found",
+				op.OutputIndex)
+			if utxo.Outpoint.OutputIndex != op.OutputIndex {
+				continue
+			}
+
+			return nil
+		}
+
+		return err
+	}, DefaultTimeout)
+
+	require.NoErrorf(h, err, "outpoint %v not found in %s's wallet",
+		op, hn.Name())
+}
+
+// AssertWalletAccountBalance asserts that the unconfirmed and confirmed
+// balance for the given account is satisfied by the WalletBalance and
+// ListUnspent RPCs. The unconfirmed balance is not checked for neutrino nodes.
+func (h *HarnessTest) AssertWalletAccountBalance(hn *node.HarnessNode,
+	account string, confirmedBalance, unconfirmedBalance int64) {
+
+	err := wait.NoError(func() error {
+		balanceResp := hn.RPC.WalletBalance()
+		require.Contains(h, balanceResp.AccountBalance, account)
+		accountBalance := balanceResp.AccountBalance[account]
+
+		// Check confirmed balance.
+		if accountBalance.ConfirmedBalance != confirmedBalance {
+			return fmt.Errorf("expected confirmed balance %v, "+
+				"got %v", confirmedBalance,
+				accountBalance.ConfirmedBalance)
+		}
+
+		utxos := h.GetUTXOsConfirmed(hn, account)
+		var totalConfirmedVal int64
+		for _, utxo := range utxos {
+			totalConfirmedVal += utxo.AmountSat
+		}
+		if totalConfirmedVal != confirmedBalance {
+			return fmt.Errorf("expected total confirmed utxo "+
+				"balance %v, got %v", confirmedBalance,
+				totalConfirmedVal)
+		}
+
+		// Skip unconfirmed balance checks for neutrino nodes.
+		if h.IsNeutrinoBackend() {
+			return nil
+		}
+
+		// Check unconfirmed balance.
+		if accountBalance.UnconfirmedBalance != unconfirmedBalance {
+			return fmt.Errorf("expected unconfirmed balance %v, "+
+				"got %v", unconfirmedBalance,
+				accountBalance.UnconfirmedBalance)
+		}
+
+		utxos = h.GetUTXOsUnconfirmed(hn, account)
+		var totalUnconfirmedVal int64
+		for _, utxo := range utxos {
+			totalUnconfirmedVal += utxo.AmountSat
+		}
+		if totalUnconfirmedVal != unconfirmedBalance {
+			return fmt.Errorf("expected total unconfirmed utxo "+
+				"balance %v, got %v", unconfirmedBalance,
+				totalUnconfirmedVal)
+		}
+
+		return nil
+	}, DefaultTimeout)
+	require.NoError(h, err, "timeout checking wallet account balance")
+}

lntemp/harness_miner.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
@@ -253,6 +254,16 @@ func (h *HarnessMiner) GetRawTransaction(txid *chainhash.Hash) *btcutil.Tx {
 	return tx
 }
 
+// GetRawTransactionVerbose makes a RPC call to the miner's
+// GetRawTransactionVerbose and asserts.
+func (h *HarnessMiner) GetRawTransactionVerbose(
+	txid *chainhash.Hash) *btcjson.TxRawResult {
+
+	tx, err := h.Client.GetRawTransactionVerbose(txid)
+	require.NoErrorf(h, err, "failed to get raw tx verbose: %v", txid)
+	return tx
+}
+
 // AssertTxInMempool asserts a given transaction can be found in the mempool.
 func (h *HarnessMiner) AssertTxInMempool(txid *chainhash.Hash) *wire.MsgTx {
 	var msgTx *wire.MsgTx

lntemp/node/harness_node.go

@@ -135,15 +135,24 @@ func NewHarnessNode(t *testing.T, cfg *BaseNodeConfig) (*HarnessNode, error) {
 	}, nil
 }
 
-// InitRPCClients initializes a list of RPC clients for the node.
-func (hn *HarnessNode) InitRPCClients(c *grpc.ClientConn) {
+// Initialize creates a list of new RPC clients using the passed connection,
+// initializes the node's internal state and creates a topology watcher.
+func (hn *HarnessNode) Initialize(c *grpc.ClientConn) {
 	hn.conn = c
 
 	// Init all the rpc clients.
 	hn.RPC = rpc.NewHarnessRPC(hn.runCtx, hn.T, c, hn.Name())
 
-	// Init the node's internal state.
-	hn.State = newState(hn.RPC)
+	// Init the node's state.
+	//
+	// If we already have a state, it means we are restarting the node and
+	// we will only reset its internal states. Otherwise we'll create a new
+	// state.
+	if hn.State != nil {
+		hn.State.resetEphermalStates(hn.RPC)
+	} else {
+		hn.State = newState(hn.RPC)
+	}
 
 	// Init the topology watcher.
 	hn.Watcher = newNodeWatcher(hn.RPC, hn.State)
@@ -164,11 +173,11 @@ func (hn *HarnessNode) String() string {
 	type nodeCfg struct {
 		LogFilenamePrefix string
 		ExtraArgs         []string
-		HasSeed           bool
+		SkipUnlock        bool
+		Password          []byte
 		P2PPort           int
 		RPCPort           int
 		RESTPort          int
-		ProfilePort       int
 		AcceptKeySend     bool
 		FeeURL            string
 	}
@@ -185,6 +194,8 @@ func (hn *HarnessNode) String() string {
 		PubKey: hn.PubKeyStr,
 		State:  hn.State,
 		NodeCfg: nodeCfg{
+			SkipUnlock:        hn.Cfg.SkipUnlock,
+			Password:          hn.Cfg.Password,
 			LogFilenamePrefix: hn.Cfg.LogFilenamePrefix,
 			ExtraArgs:         hn.Cfg.ExtraArgs,
 			P2PPort:           hn.Cfg.P2PPort,
@@ -434,8 +445,9 @@ func (hn *HarnessNode) Start(ctxt context.Context) error {
 		return err
 	}
 
-	// Init all the RPC clients.
-	hn.InitRPCClients(conn)
+	// Init the node by creating the RPC clients, initializing node's
+	// internal state and watcher.
+	hn.Initialize(conn)
 
 	// Wait till the server is starting.
 	if err := hn.WaitUntilStarted(); err != nil {
@@ -477,8 +489,9 @@ func (hn *HarnessNode) InitNode(macBytes []byte) error {
 		}
 	}
 
-	// Init all the RPC clients.
-	hn.InitRPCClients(conn)
+	// Init the node by creating the RPC clients, initializing node's
+	// internal state and watcher.
+	hn.Initialize(conn)
 
 	// Wait till the server is starting.
 	if err := hn.WaitUntilStarted(); err != nil {

lntemp/node/state.go

@@ -241,6 +241,14 @@ func (s *State) updatePaymentStats() {
 	}
 	resp := s.rpc.ListPayments(req)
 
+	// Exit early when the there's no payment.
+	//
+	// NOTE: we need to exit early here because when there's no invoice the
+	// `LastOffsetIndex` will be zero.
+	if len(resp.Payments) == 0 {
+		return
+	}
+
 	s.Payment.LastIndexOffset = resp.LastIndexOffset
 	for _, payment := range resp.Payments {
 		if payment.Status == lnrpc.Payment_FAILED ||
@@ -261,6 +269,14 @@ func (s *State) updateInvoiceStats() {
 	}
 	resp := s.rpc.ListInvoices(req)
 
+	// Exit early when the there's no invoice.
+	//
+	// NOTE: we need to exit early here because when there's no invoice the
+	// `LastOffsetIndex` will be zero.
+	if len(resp.Invoices) == 0 {
+		return
+	}
+
 	s.Invoice.LastIndexOffset = resp.LastIndexOffset
 	for _, invoice := range resp.Invoices {
 		if invoice.State == lnrpc.Invoice_SETTLED ||
@@ -328,3 +344,17 @@ func (s *State) String() string {
 
 	return fmt.Sprintf("\n%s", stateBytes)
 }
+
+// resetEphermalStates resets the current state with a new HarnessRPC and empty
+// private fields which are used to track state only valid for the last test.
+func (s *State) resetEphermalStates(rpc *rpc.HarnessRPC) {
+	s.rpc = rpc
+
+	// Reset ephermal states which are used to record info from finished
+	// tests.
+	s.openChans = &SyncMap[wire.OutPoint, []*OpenChannelUpdate]{}
+	s.closedChans = &SyncMap[wire.OutPoint, *lnrpc.ClosedChannelUpdate]{}
+	s.numChanUpdates = &SyncMap[wire.OutPoint, int]{}
+	s.nodeUpdates = &SyncMap[string, []*lnrpc.NodeUpdate]{}
+	s.policyUpdates = &SyncMap[wire.OutPoint, PolicyUpdate]{}
+}

lntemp/rpc/chain_notifier.go

@@ -1,5 +1,44 @@
 package rpc
 
+import (
+	"github.com/lightningnetwork/lnd/lnrpc/chainrpc"
+)
+
 // =====================
 // ChainClient related RPCs.
 // =====================
+
+type ConfNtfnClient chainrpc.ChainNotifier_RegisterConfirmationsNtfnClient
+
+// RegisterConfirmationsNtfn creates a notification client to watch a given
+// transaction being confirmed.
+func (h *HarnessRPC) RegisterConfirmationsNtfn(
+	req *chainrpc.ConfRequest) ConfNtfnClient {
+
+	// RegisterConfirmationsNtfn needs to have the context alive for the
+	// entire test case as the returned client will be used for send and
+	// receive events stream. Thus we use runCtx here instead of a timeout
+	// context.
+	client, err := h.ChainClient.RegisterConfirmationsNtfn(
+		h.runCtx, req,
+	)
+	h.NoError(err, "RegisterConfirmationsNtfn")
+
+	return client
+}
+
+type SpendClient chainrpc.ChainNotifier_RegisterSpendNtfnClient
+
+// RegisterSpendNtfn creates a notification client to watch a given
+// transaction being spent.
+func (h *HarnessRPC) RegisterSpendNtfn(req *chainrpc.SpendRequest) SpendClient {
+	// RegisterSpendNtfn needs to have the context alive for the entire
+	// test case as the returned client will be used for send and receive
+	// events stream. Thus we use runCtx here instead of a timeout context.
+	client, err := h.ChainClient.RegisterSpendNtfn(
+		h.runCtx, req,
+	)
+	h.NoError(err, "RegisterSpendNtfn")
+
+	return client
+}

lntemp/rpc/lnd.go

@@ -631,3 +631,54 @@ func (h *HarnessRPC) RegisterRPCMiddleware() (MiddlewareClient,
 
 	return stream, cancel
 }
+
+type ChannelEventsClient lnrpc.Lightning_SubscribeChannelEventsClient
+
+// SubscribeChannelEvents creates a subscription client for channel events and
+// asserts its creation.
+func (h *HarnessRPC) SubscribeChannelEvents() ChannelEventsClient {
+	req := &lnrpc.ChannelEventSubscription{}
+
+	// SubscribeChannelEvents needs to have the context alive for the
+	// entire test case as the returned client will be used for send and
+	// receive events stream. Thus we use runCtx here instead of a timeout
+	// context.
+	client, err := h.LN.SubscribeChannelEvents(h.runCtx, req)
+	h.NoError(err, "SubscribeChannelEvents")
+
+	return client
+}
+
+type CustomMessageClient lnrpc.Lightning_SubscribeCustomMessagesClient
+
+// SubscribeCustomMessages creates a subscription client for custom messages.
+func (h *HarnessRPC) SubscribeCustomMessages() (CustomMessageClient,
+	context.CancelFunc) {
+
+	ctxt, cancel := context.WithCancel(h.runCtx)
+
+	req := &lnrpc.SubscribeCustomMessagesRequest{}
+
+	// SubscribeCustomMessages needs to have the context alive for the
+	// entire test case as the returned client will be used for send and
+	// receive events stream. Thus we use runCtx here instead of a timeout
+	// context.
+	stream, err := h.LN.SubscribeCustomMessages(ctxt, req)
+	h.NoError(err, "SubscribeCustomMessages")
+
+	return stream, cancel
+}
+
+// SendCustomMessage makes a RPC call to the node's SendCustomMessage and
+// returns the response.
+func (h *HarnessRPC) SendCustomMessage(
+	req *lnrpc.SendCustomMessageRequest) *lnrpc.SendCustomMessageResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.LN.SendCustomMessage(ctxt, req)
+	h.NoError(err, "SendCustomMessage")
+
+	return resp
+}

lntemp/rpc/router.go

@@ -150,3 +150,43 @@ func (h *HarnessRPC) XImportMissionControlAssertErr(
 	_, err := h.Router.XImportMissionControl(ctxt, req)
 	require.Error(h, err, "expect an error from x import mission control")
 }
+
+// BuildRoute makes a RPC call to the node's RouterClient and asserts.
+func (h *HarnessRPC) BuildRoute(
+	req *routerrpc.BuildRouteRequest) *routerrpc.BuildRouteResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Router.BuildRoute(ctxt, req)
+	h.NoError(err, "BuildRoute")
+
+	return resp
+}
+
+type InterceptorClient routerrpc.Router_HtlcInterceptorClient
+
+// HtlcInterceptor makes a RPC call to the node's RouterClient and asserts.
+func (h *HarnessRPC) HtlcInterceptor() (InterceptorClient, context.CancelFunc) {
+	// HtlcInterceptor needs to have the context alive for the entire test
+	// case as the returned client will be used for send and receive events
+	// stream. Thus we use cancel context here instead of a timeout
+	// context.
+	ctxt, cancel := context.WithCancel(h.runCtx)
+	resp, err := h.Router.HtlcInterceptor(ctxt)
+	h.NoError(err, "HtlcInterceptor")
+
+	return resp, cancel
+}
+
+type TrackPaymentsClient routerrpc.Router_TrackPaymentsClient
+
+// TrackPayments makes a RPC call to the node's RouterClient and asserts.
+func (h *HarnessRPC) TrackPayments(
+	req *routerrpc.TrackPaymentsRequest) TrackPaymentsClient {
+
+	resp, err := h.Router.TrackPayments(h.runCtx, req)
+	h.NoError(err, "TrackPayments")
+
+	return resp
+}

lntemp/rpc/signer.go

@@ -4,13 +4,39 @@ import (
 	"context"
 
 	"github.com/lightningnetwork/lnd/lnrpc/signrpc"
+	"github.com/stretchr/testify/require"
 )
 
 // =====================
 // Signer related RPCs.
 // =====================
 
-// SignOutputRaw makes a RPC call to node's SignOutputRaw and asserts.
+// DeriveSharedKey makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) DeriveSharedKey(
+	req *signrpc.SharedKeyRequest) *signrpc.SharedKeyResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.DeriveSharedKey(ctxt, req)
+	h.NoError(err, "DeriveSharedKey")
+
+	return resp
+}
+
+// DeriveSharedKeyErr makes a RPC call to the node's SignerClient and asserts
+// there is an error.
+func (h *HarnessRPC) DeriveSharedKeyErr(req *signrpc.SharedKeyRequest) error {
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	_, err := h.Signer.DeriveSharedKey(ctxt, req)
+	require.Error(h, err, "expected error from calling DeriveSharedKey")
+
+	return err
+}
+
+// SignOutputRaw makes a RPC call to the node's SignerClient and asserts.
 func (h *HarnessRPC) SignOutputRaw(req *signrpc.SignReq) *signrpc.SignResp {
 	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
 	defer cancel()
@@ -20,3 +46,152 @@ func (h *HarnessRPC) SignOutputRaw(req *signrpc.SignReq) *signrpc.SignResp {
 
 	return resp
 }
+
+// SignOutputRawErr makes a RPC call to the node's SignerClient and asserts an
+// error is returned.
+func (h *HarnessRPC) SignOutputRawErr(req *signrpc.SignReq) error {
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	_, err := h.Signer.SignOutputRaw(ctxt, req)
+	require.Error(h, err, "expect to fail to sign raw output")
+
+	return err
+}
+
+// MuSig2CreateSession makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) MuSig2CreateSession(
+	req *signrpc.MuSig2SessionRequest) *signrpc.MuSig2SessionResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2CreateSession(ctxt, req)
+	h.NoError(err, "MuSig2CreateSession")
+
+	return resp
+}
+
+// MuSig2CombineKeys makes a RPC call to the node's SignerClient and asserts.
+//
+//nolint:lll
+func (h *HarnessRPC) MuSig2CombineKeys(
+	req *signrpc.MuSig2CombineKeysRequest) *signrpc.MuSig2CombineKeysResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2CombineKeys(ctxt, req)
+	h.NoError(err, "MuSig2CombineKeys")
+
+	return resp
+}
+
+// MuSig2RegisterNonces makes a RPC call to the node's SignerClient and asserts.
+//
+//nolint:lll
+func (h *HarnessRPC) MuSig2RegisterNonces(
+	req *signrpc.MuSig2RegisterNoncesRequest) *signrpc.MuSig2RegisterNoncesResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2RegisterNonces(ctxt, req)
+	h.NoError(err, "MuSig2RegisterNonces")
+
+	return resp
+}
+
+// MuSig2Sign makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) MuSig2Sign(
+	req *signrpc.MuSig2SignRequest) *signrpc.MuSig2SignResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2Sign(ctxt, req)
+	h.NoError(err, "MuSig2Sign")
+
+	return resp
+}
+
+// MuSig2SignErr makes a RPC call to the node's SignerClient and asserts an
+// error is returned.
+func (h *HarnessRPC) MuSig2SignErr(req *signrpc.MuSig2SignRequest) error {
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	_, err := h.Signer.MuSig2Sign(ctxt, req)
+	require.Error(h, err, "expect an error")
+
+	return err
+}
+
+// MuSig2CombineSig makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) MuSig2CombineSig(
+	r *signrpc.MuSig2CombineSigRequest) *signrpc.MuSig2CombineSigResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2CombineSig(ctxt, r)
+	h.NoError(err, "MuSig2CombineSig")
+
+	return resp
+}
+
+// MuSig2Cleanup makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) MuSig2Cleanup(
+	req *signrpc.MuSig2CleanupRequest) *signrpc.MuSig2CleanupResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.MuSig2Cleanup(ctxt, req)
+	h.NoError(err, "MuSig2Cleanup")
+
+	return resp
+}
+
+// SignMessageSigner makes a RPC call to the node's SignerClient and asserts.
+//
+// NOTE: there's already `SignMessage` in `h.LN`.
+func (h *HarnessRPC) SignMessageSigner(
+	req *signrpc.SignMessageReq) *signrpc.SignMessageResp {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.SignMessage(ctxt, req)
+	h.NoError(err, "SignMessage")
+
+	return resp
+}
+
+// VerifyMessageSigner makes a RPC call to the node's SignerClient and asserts.
+//
+// NOTE: there's already `VerifyMessageSigner` in `h.LN`.
+func (h *HarnessRPC) VerifyMessageSigner(
+	req *signrpc.VerifyMessageReq) *signrpc.VerifyMessageResp {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.VerifyMessage(ctxt, req)
+	h.NoError(err, "VerifyMessage")
+
+	return resp
+}
+
+// ComputeInputScript makes a RPC call to the node's SignerClient and asserts.
+func (h *HarnessRPC) ComputeInputScript(
+	req *signrpc.SignReq) *signrpc.InputScriptResp {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.Signer.ComputeInputScript(ctxt, req)
+	h.NoError(err, "ComputeInputScript")
+
+	return resp
+}

lntemp/rpc/wallet_kit.go

@@ -163,3 +163,85 @@ func (h *HarnessRPC) PublishTransaction(
 
 	return resp
 }
+
+// BumpFee makes a RPC call to the node's WalletKitClient and asserts.
+func (h *HarnessRPC) BumpFee(
+	req *walletrpc.BumpFeeRequest) *walletrpc.BumpFeeResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.BumpFee(ctxt, req)
+	h.NoError(err, "BumpFee")
+
+	return resp
+}
+
+// ListAccounts makes a RPC call to the node's WalletKitClient and asserts.
+func (h *HarnessRPC) ListAccounts(
+	req *walletrpc.ListAccountsRequest) *walletrpc.ListAccountsResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.ListAccounts(ctxt, req)
+	h.NoError(err, "ListAccounts")
+
+	return resp
+}
+
+// ImportAccount makes a RPC call to the node's WalletKitClient and asserts.
+func (h *HarnessRPC) ImportAccount(
+	req *walletrpc.ImportAccountRequest) *walletrpc.ImportAccountResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.ImportAccount(ctxt, req)
+	h.NoError(err, "ImportAccount")
+
+	return resp
+}
+
+// ImportPublicKey makes a RPC call to the node's WalletKitClient and asserts.
+//
+//nolint:lll
+func (h *HarnessRPC) ImportPublicKey(
+	req *walletrpc.ImportPublicKeyRequest) *walletrpc.ImportPublicKeyResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.ImportPublicKey(ctxt, req)
+	h.NoError(err, "ImportPublicKey")
+
+	return resp
+}
+
+// SignPsbt makes a RPC call to the node's WalletKitClient and asserts.
+func (h *HarnessRPC) SignPsbt(
+	req *walletrpc.SignPsbtRequest) *walletrpc.SignPsbtResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.SignPsbt(ctxt, req)
+	h.NoError(err, "SignPsbt")
+
+	return resp
+}
+
+// ImportTapscript makes a RPC call to the node's WalletKitClient and asserts.
+//
+//nolint:lll
+func (h *HarnessRPC) ImportTapscript(
+	req *walletrpc.ImportTapscriptRequest) *walletrpc.ImportTapscriptResponse {
+
+	ctxt, cancel := context.WithTimeout(h.runCtx, DefaultTimeout)
+	defer cancel()
+
+	resp, err := h.WalletKit.ImportTapscript(ctxt, req)
+	h.NoError(err, "ImportTapscript")
+
+	return resp
+}

lntest/itest/assertions.go

@@ -949,60 +949,6 @@ func assertNumPendingChannels(t *harnessTest, node *lntest.HarnessNode,
 	require.NoErrorf(t.t, err, "got err: %v", predErr)
 }
 
-// verifyCloseUpdate is used to verify that a closed channel update is of the
-// expected type.
-func verifyCloseUpdate(chanUpdate *lnrpc.ChannelEventUpdate,
-	closeType lnrpc.ChannelCloseSummary_ClosureType,
-	closeInitiator lnrpc.Initiator) error {
-
-	// We should receive one inactive and one closed notification
-	// for each channel.
-	switch update := chanUpdate.Channel.(type) {
-	case *lnrpc.ChannelEventUpdate_InactiveChannel:
-		if chanUpdate.Type != lnrpc.ChannelEventUpdate_INACTIVE_CHANNEL {
-			return fmt.Errorf("update type mismatch: expected %v, got %v",
-				lnrpc.ChannelEventUpdate_INACTIVE_CHANNEL,
-				chanUpdate.Type)
-		}
-
-	case *lnrpc.ChannelEventUpdate_ClosedChannel:
-		if chanUpdate.Type !=
-			lnrpc.ChannelEventUpdate_CLOSED_CHANNEL {
-
-			return fmt.Errorf("update type mismatch: expected %v, got %v",
-				lnrpc.ChannelEventUpdate_CLOSED_CHANNEL,
-				chanUpdate.Type)
-		}
-
-		if update.ClosedChannel.CloseType != closeType {
-			return fmt.Errorf("channel closure type "+
-				"mismatch: expected %v, got %v",
-				closeType,
-				update.ClosedChannel.CloseType)
-		}
-
-		if update.ClosedChannel.CloseInitiator != closeInitiator {
-			return fmt.Errorf("expected close intiator: %v, got: %v",
-				closeInitiator,
-				update.ClosedChannel.CloseInitiator)
-		}
-
-	case *lnrpc.ChannelEventUpdate_FullyResolvedChannel:
-		if chanUpdate.Type != lnrpc.ChannelEventUpdate_FULLY_RESOLVED_CHANNEL {
-			return fmt.Errorf("update type mismatch: expected %v, got %v",
-				lnrpc.ChannelEventUpdate_FULLY_RESOLVED_CHANNEL,
-				chanUpdate.Type)
-		}
-
-	default:
-		return fmt.Errorf("channel update channel of wrong type, "+
-			"expected closed channel, got %T",
-			update)
-	}
-
-	return nil
-}
-
 // assertNodeNumChannels polls the provided node's list channels rpc until it
 // reaches the desired number of total channels.
 func assertNodeNumChannels(t *harnessTest, node *lntest.HarnessNode,

lntest/itest/list_on_test.go

@@ -275,6 +275,10 @@ var allTestCasesTemp = []*lntemp.TestCase{
 		Name:     "open channel reorg test",
 		TestFunc: testOpenChannelAfterReorg,
 	},
+	{
+		Name:     "psbt channel funding",
+		TestFunc: testPsbtChanFunding,
+	},
 	{
 		Name:     "psbt channel funding external",
 		TestFunc: testPsbtChanFundingExternal,
@@ -283,6 +287,10 @@ var allTestCasesTemp = []*lntemp.TestCase{
 		Name:     "psbt channel funding single step",
 		TestFunc: testPsbtChanFundingSingleStep,
 	},
+	{
+		Name:     "sign psbt",
+		TestFunc: testSignPsbt,
+	},
 	{
 		Name:     "resolution handoff",
 		TestFunc: testResHandoff,
@@ -369,4 +377,128 @@ var allTestCasesTemp = []*lntemp.TestCase{
 		Name:     "wipe forwarding packages",
 		TestFunc: testWipeForwardingPackages,
 	},
+	{
+		Name:     "switch circuit persistence",
+		TestFunc: testSwitchCircuitPersistence,
+	},
+	{
+		Name:     "switch offline delivery",
+		TestFunc: testSwitchOfflineDelivery,
+	},
+	{
+		Name:     "switch offline delivery persistence",
+		TestFunc: testSwitchOfflineDeliveryPersistence,
+	},
+	{
+		Name:     "switch offline delivery outgoing offline",
+		TestFunc: testSwitchOfflineDeliveryOutgoingOffline,
+	},
+	{
+		Name:     "sendtoroute multi path payment",
+		TestFunc: testSendToRouteMultiPath,
+	},
+	{
+		Name:     "send multi path payment",
+		TestFunc: testSendMultiPathPayment,
+	},
+	{
+		Name:     "sendpayment amp invoice",
+		TestFunc: testSendPaymentAMPInvoice,
+	},
+	{
+		Name:     "sendpayment amp invoice repeat",
+		TestFunc: testSendPaymentAMPInvoiceRepeat,
+	},
+	{
+		Name:     "send payment amp",
+		TestFunc: testSendPaymentAMP,
+	},
+	{
+		Name:     "sendtoroute amp",
+		TestFunc: testSendToRouteAMP,
+	},
+	{
+		Name:     "forward interceptor dedup htlcs",
+		TestFunc: testForwardInterceptorDedupHtlc,
+	},
+	{
+		Name:     "forward interceptor",
+		TestFunc: testForwardInterceptorBasic,
+	},
+	{
+		Name:     "zero conf channel open",
+		TestFunc: testZeroConfChannelOpen,
+	},
+	{
+		Name:     "option scid alias",
+		TestFunc: testOptionScidAlias,
+	},
+	{
+		Name:     "scid alias channel update",
+		TestFunc: testUpdateChannelPolicyScidAlias,
+	},
+	{
+		Name:     "scid alias upgrade",
+		TestFunc: testOptionScidUpgrade,
+	},
+	{
+		Name:     "nonstd sweep",
+		TestFunc: testNonstdSweep,
+	},
+	{
+		Name:     "multiple channel creation and update subscription",
+		TestFunc: testBasicChannelCreationAndUpdates,
+	},
+	{
+		Name:     "derive shared key",
+		TestFunc: testDeriveSharedKey,
+	},
+	{
+		Name:     "sign output raw",
+		TestFunc: testSignOutputRaw,
+	},
+	{
+		Name:     "sign verify message",
+		TestFunc: testSignVerifyMessage,
+	},
+	{
+		Name:     "cpfp",
+		TestFunc: testCPFP,
+	},
+	{
+		Name:     "taproot",
+		TestFunc: testTaproot,
+	},
+	{
+		Name:     "wallet import account",
+		TestFunc: testWalletImportAccount,
+	},
+	{
+		Name:     "wallet import pubkey",
+		TestFunc: testWalletImportPubKey,
+	},
+	{
+		Name:     "async payments benchmark",
+		TestFunc: testAsyncPayments,
+	},
+	{
+		Name:     "remote signer",
+		TestFunc: testRemoteSigner,
+	},
+	{
+		Name:     "taproot coop close",
+		TestFunc: testTaprootCoopClose,
+	},
+	{
+		Name:     "trackpayments",
+		TestFunc: testTrackPayments,
+	},
+	{
+		Name:     "open channel fee policy",
+		TestFunc: testOpenChannelUpdateFeePolicy,
+	},
+	{
+		Name:     "custom message",
+		TestFunc: testCustomMessage,
+	},
 }

lntest/itest/lnd_amp_test.go

@@ -1,10 +1,7 @@
 package itest
 
 import (
-	"context"
-	"crypto/rand"
 	"encoding/hex"
-	"sort"
 	"testing"
 	"time"
 
@@ -14,40 +11,41 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/invoicesrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/stretchr/testify/require"
 )
 
 // testSendPaymentAMPInvoice tests that we can send an AMP payment to a
 // specified AMP invoice using SendPaymentV2.
-func testSendPaymentAMPInvoice(net *lntest.NetworkHarness, t *harnessTest) {
-	t.t.Run("native payaddr", func(t *testing.T) {
-		tt := newHarnessTest(t, net)
-		testSendPaymentAMPInvoiceCase(net, tt, false)
+func testSendPaymentAMPInvoice(ht *lntemp.HarnessTest) {
+	succeed := ht.Run("native payaddr", func(t *testing.T) {
+		tt := ht.Subtest(t)
+		testSendPaymentAMPInvoiceCase(tt, false)
 	})
-	t.t.Run("external payaddr", func(t *testing.T) {
-		tt := newHarnessTest(t, net)
-		testSendPaymentAMPInvoiceCase(net, tt, true)
+
+	// Abort the test if failed.
+	if !succeed {
+		return
+	}
+
+	ht.Run("external payaddr", func(t *testing.T) {
+		tt := ht.Subtest(t)
+		testSendPaymentAMPInvoiceCase(tt, true)
 	})
 }
 
-func testSendPaymentAMPInvoiceCase(net *lntest.NetworkHarness, t *harnessTest,
+func testSendPaymentAMPInvoiceCase(ht *lntemp.HarnessTest,
 	useExternalPayAddr bool) {
 
-	ctxb := context.Background()
-
-	ctx := newMppTestContext(t, net)
-	defer ctx.shutdownNodes()
+	mts := newMppTestScenario(ht)
 
 	// Subscribe to bob's invoices. Do this early in the test to make sure
 	// that the subscription has actually been completed when we add an
 	// invoice. Otherwise the notification will be missed.
 	req := &lnrpc.InvoiceSubscription{}
-	ctxc, cancelSubscription := context.WithCancel(ctxb)
-	bobInvoiceSubscription, err := ctx.bob.SubscribeInvoices(ctxc, req)
-	require.NoError(t.t, err)
-	defer cancelSubscription()
+	bobInvoiceSubscription := mts.bob.RPC.SubscribeInvoices(req)
 
 	const paymentAmt = btcutil.Amount(300000)
 
@@ -61,49 +59,45 @@ func testSendPaymentAMPInvoiceCase(net *lntest.NetworkHarness, t *harnessTest,
 	//      \              /
 	//       \__ Dave ____/
 	//
-	ctx.openChannel(ctx.carol, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.carol, 235000)
-	ctx.openChannel(ctx.dave, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.dave, 135000)
-	ctx.openChannel(ctx.eve, ctx.bob, 135000)
-	ctx.openChannel(ctx.carol, ctx.eve, 135000)
+	mppReq := &mppOpenChannelRequest{
+		amtAliceCarol: 235000,
+		amtAliceDave:  135000,
+		amtCarolBob:   135000,
+		amtCarolEve:   135000,
+		amtDaveBob:    135000,
+		amtEveBob:     135000,
+	}
+	mts.openChannels(mppReq)
+	chanPointAliceDave := mts.channelPoints[1]
+	chanPointDaveBob := mts.channelPoints[4]
 
-	defer ctx.closeChannels()
-
-	ctx.waitForChannels()
-
-	addInvoiceResp, err := ctx.bob.AddInvoice(context.Background(), &lnrpc.Invoice{
+	invoice := &lnrpc.Invoice{
 		Value: int64(paymentAmt),
 		IsAmp: true,
-	})
-	require.NoError(t.t, err)
+	}
+	addInvoiceResp := mts.bob.RPC.AddInvoice(invoice)
 
 	// Ensure we get a notification of the invoice being added by Bob.
-	rpcInvoice, err := bobInvoiceSubscription.Recv()
-	require.NoError(t.t, err)
+	rpcInvoice := ht.ReceiveInvoiceUpdate(bobInvoiceSubscription)
 
-	require.False(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_OPEN, rpcInvoice.State)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidMsat)
-
-	require.Equal(t.t, 0, len(rpcInvoice.Htlcs))
+	require.False(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_OPEN, rpcInvoice.State)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidMsat)
+	require.Equal(ht, 0, len(rpcInvoice.Htlcs))
 
 	// Increase Dave's fee to make the test deterministic. Otherwise it
 	// would be unpredictable whether pathfinding would go through Charlie
 	// or Dave for the first shard.
-	_, err = ctx.dave.UpdateChannelPolicy(
-		context.Background(),
-		&lnrpc.PolicyUpdateRequest{
-			Scope:         &lnrpc.PolicyUpdateRequest_Global{Global: true},
-			BaseFeeMsat:   500000,
-			FeeRate:       0.001,
-			TimeLockDelta: 40,
-		},
+	expectedPolicy := mts.updateDaveGlobalPolicy()
+
+	// Make sure Alice has heard it for both Dave's channels.
+	ht.AssertChannelPolicyUpdate(
+		mts.alice, mts.dave, expectedPolicy, chanPointAliceDave, false,
+	)
+	ht.AssertChannelPolicyUpdate(
+		mts.alice, mts.dave, expectedPolicy, chanPointDaveBob, false,
 	)
-	if err != nil {
-		t.Fatalf("dave policy update: %v", err)
-	}
 
 	// Generate an external payment address when attempting to pseudo-reuse
 	// an AMP invoice. When using an external payment address, we'll also
@@ -116,19 +110,16 @@ func testSendPaymentAMPInvoiceCase(net *lntest.NetworkHarness, t *harnessTest,
 	)
 	if useExternalPayAddr {
 		expNumInvoices = 2
-		externalPayAddr = make([]byte, 32)
-		_, err = rand.Read(externalPayAddr)
-		require.NoError(t.t, err)
+		externalPayAddr = ht.Random32Bytes()
 	}
 
-	payment := sendAndAssertSuccess(
-		t, ctx.alice, &routerrpc.SendPaymentRequest{
-			PaymentRequest: addInvoiceResp.PaymentRequest,
-			PaymentAddr:    externalPayAddr,
-			TimeoutSeconds: 60,
-			FeeLimitMsat:   noFeeLimitMsat,
-		},
-	)
+	sendReq := &routerrpc.SendPaymentRequest{
+		PaymentRequest: addInvoiceResp.PaymentRequest,
+		PaymentAddr:    externalPayAddr,
+		TimeoutSeconds: 60,
+		FeeLimitMsat:   noFeeLimitMsat,
+	}
+	payment := ht.SendPaymentAssertSettled(mts.alice, sendReq)
 
 	// Check that Alice split the payment in at least three shards. Because
 	// the hand-off of the htlc to the link is asynchronous (via a mailbox),
@@ -145,232 +136,201 @@ func testSendPaymentAMPInvoiceCase(net *lntest.NetworkHarness, t *harnessTest,
 	}
 
 	const minExpectedShards = 3
-	if succeeded < minExpectedShards {
-		t.Fatalf("expected at least %v shards, but got %v",
-			minExpectedShards, succeeded)
-	}
+	require.GreaterOrEqual(ht, succeeded, minExpectedShards,
+		"expected num of shards not reached")
 
 	// When an external payment address is supplied, we'll get an extra
 	// notification for the JIT inserted invoice, since it differs from the
 	// original.
 	if useExternalPayAddr {
-		_, err = bobInvoiceSubscription.Recv()
-		require.NoError(t.t, err)
+		ht.ReceiveInvoiceUpdate(bobInvoiceSubscription)
 	}
 
 	// There should now be a settle event for the invoice.
-	rpcInvoice, err = bobInvoiceSubscription.Recv()
-	require.NoError(t.t, err)
+	rpcInvoice = ht.ReceiveInvoiceUpdate(bobInvoiceSubscription)
 
 	// Also fetch Bob's invoice from ListInvoices and assert it is equal to
 	// the one received via the subscription.
-	invoiceResp, err := ctx.bob.ListInvoices(
-		ctxb, &lnrpc.ListInvoiceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Equal(t.t, expNumInvoices, len(invoiceResp.Invoices))
-	assertInvoiceEqual(t.t, rpcInvoice, invoiceResp.Invoices[expNumInvoices-1])
+	invoices := ht.AssertNumInvoices(mts.bob, expNumInvoices)
+	ht.AssertInvoiceEqual(rpcInvoice, invoices[expNumInvoices-1])
 
 	// Assert that the invoice is settled for the total payment amount and
 	// has the correct payment address.
-	require.True(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_SETTLED, rpcInvoice.State)
-	require.Equal(t.t, int64(paymentAmt), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
+	require.True(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_SETTLED, rpcInvoice.State)
+	require.Equal(ht, int64(paymentAmt), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
 
 	// Finally, assert that the same set id is recorded for each htlc, and
 	// that the preimage hash pair is valid.
 	var setID []byte
-	require.Equal(t.t, succeeded, len(rpcInvoice.Htlcs))
+	require.Equal(ht, succeeded, len(rpcInvoice.Htlcs))
 	for _, htlc := range rpcInvoice.Htlcs {
-		require.NotNil(t.t, htlc.Amp)
+		require.NotNil(ht, htlc.Amp)
 		if setID == nil {
 			setID = make([]byte, 32)
 			copy(setID, htlc.Amp.SetId)
 		}
-		require.Equal(t.t, setID, htlc.Amp.SetId)
+		require.Equal(ht, setID, htlc.Amp.SetId)
 
 		// Parse the child hash and child preimage, and assert they are
 		// well-formed.
 		childHash, err := lntypes.MakeHash(htlc.Amp.Hash)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 		childPreimage, err := lntypes.MakePreimage(htlc.Amp.Preimage)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 
 		// Assert that the preimage actually matches the hashes.
 		validPreimage := childPreimage.Matches(childHash)
-		require.True(t.t, validPreimage)
+		require.True(ht, validPreimage)
 	}
 
 	// The set ID we extract above should be shown in the final settled
 	// state.
 	ampState := rpcInvoice.AmpInvoiceState[hex.EncodeToString(setID)]
-	require.Equal(t.t, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+	require.Equal(ht, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+
+	// Finally, close all channels.
+	mts.closeChannels()
 }
 
 // testSendPaymentAMPInvoiceRepeat tests that it's possible to pay an AMP
 // invoice multiple times by having the client generate a new setID each time.
-func testSendPaymentAMPInvoiceRepeat(net *lntest.NetworkHarness,
-	t *harnessTest) {
-
+func testSendPaymentAMPInvoiceRepeat(ht *lntemp.HarnessTest) {
 	// In this basic test, we'll only need two nodes as we want to
 	// primarily test the recurring payment feature. So we'll re-use the
-	carol := net.NewNode(t.t, "Carol", nil)
-	defer shutdownAndAssert(net, t, carol)
+	carol := ht.NewNode("Carol", nil)
 
 	// Send Carol enough coins to be able to open a channel to Dave.
-	net.SendCoins(t.t, btcutil.SatoshiPerBitcoin, carol)
+	ht.FundCoins(btcutil.SatoshiPerBitcoin, carol)
 
-	dave := net.NewNode(t.t, "Dave", nil)
-	defer shutdownAndAssert(net, t, dave)
-
-	// Before we start the test, we'll ensure both sides are connected to
-	// the funding flow can properly be executed.
-	net.EnsureConnected(t.t, carol, dave)
+	dave := ht.NewNode("Dave", nil)
 
 	// Set up an invoice subscription so we can be notified when Dave
 	// receives his repeated payments.
 	req := &lnrpc.InvoiceSubscription{}
-	ctxb := context.Background()
-	ctxc, cancelSubscription := context.WithCancel(ctxb)
-	invSubscription, err := dave.SubscribeInvoices(ctxc, req)
-	require.NoError(t.t, err)
-	defer cancelSubscription()
+	invSubscription := dave.RPC.SubscribeInvoices(req)
+
+	// Before we start the test, we'll ensure both sides are connected to
+	// the funding flow can properly be executed.
+	ht.EnsureConnected(carol, dave)
 
 	// Establish a channel between Carol and Dave.
 	chanAmt := btcutil.Amount(100_000)
-	chanPoint := openChannelAndAssert(
-		t, net, carol, dave,
-		lntest.OpenChannelParams{
-			Amt: chanAmt,
-		},
+	ht.OpenChannel(
+		carol, dave, lntemp.OpenChannelParams{Amt: chanAmt},
 	)
-	err = carol.WaitForNetworkChannelOpen(chanPoint)
-	require.NoError(t.t, err, "carol didn't report channel")
-	err = dave.WaitForNetworkChannelOpen(chanPoint)
-	require.NoError(t.t, err, "dave didn't report channel")
 
 	// Create an AMP invoice of a trivial amount, that we'll pay repeatedly
 	// in this integration test.
 	paymentAmt := 10000
-	addInvoiceResp, err := dave.AddInvoice(ctxb, &lnrpc.Invoice{
+	invoice := &lnrpc.Invoice{
 		Value: int64(paymentAmt),
 		IsAmp: true,
-	})
-	require.NoError(t.t, err)
+	}
+	addInvoiceResp := dave.RPC.AddInvoice(invoice)
 
 	// We should get an initial notification that the HTLC has been added.
-	rpcInvoice, err := invSubscription.Recv()
-	require.NoError(t.t, err)
-	require.False(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_OPEN, rpcInvoice.State)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidMsat)
-
-	require.Equal(t.t, 0, len(rpcInvoice.Htlcs))
+	rpcInvoice := ht.ReceiveInvoiceUpdate(invSubscription)
+	require.False(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_OPEN, rpcInvoice.State)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidMsat)
+	require.Equal(ht, 0, len(rpcInvoice.Htlcs))
 
 	// Now we'll use Carol to pay the invoice that Dave created.
-	_ = sendAndAssertSuccess(
-		t, carol, &routerrpc.SendPaymentRequest{
-			PaymentRequest: addInvoiceResp.PaymentRequest,
-			TimeoutSeconds: 60,
-			FeeLimitMsat:   noFeeLimitMsat,
-		},
+	ht.CompletePaymentRequests(
+		carol, []string{addInvoiceResp.PaymentRequest},
 	)
 
 	// Dave should get a notification that the invoice has been settled.
-	invoiceNtfn, err := invSubscription.Recv()
-	require.NoError(t.t, err)
+	invoiceNtfn := ht.ReceiveInvoiceUpdate(invSubscription)
 
 	// The notification should signal that the invoice is now settled, and
 	// should also include the set ID, and show the proper amount paid.
-	require.True(t.t, invoiceNtfn.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_SETTLED, invoiceNtfn.State)
-	require.Equal(t.t, paymentAmt, int(invoiceNtfn.AmtPaidSat))
-	require.Equal(t.t, 1, len(invoiceNtfn.AmpInvoiceState))
+	require.True(ht, invoiceNtfn.Settled)
+	require.Equal(ht, lnrpc.Invoice_SETTLED, invoiceNtfn.State)
+	require.Equal(ht, paymentAmt, int(invoiceNtfn.AmtPaidSat))
+	require.Equal(ht, 1, len(invoiceNtfn.AmpInvoiceState))
 	var firstSetID []byte
 	for setIDStr, ampState := range invoiceNtfn.AmpInvoiceState {
 		firstSetID, _ = hex.DecodeString(setIDStr)
-		require.Equal(t.t, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+		require.Equal(ht, lnrpc.InvoiceHTLCState_SETTLED,
+			ampState.State)
 	}
 
 	// Pay the invoice again, we should get another notification that Dave
 	// has received another payment.
-	_ = sendAndAssertSuccess(
-		t, carol, &routerrpc.SendPaymentRequest{
-			PaymentRequest: addInvoiceResp.PaymentRequest,
-			TimeoutSeconds: 60,
-			FeeLimitMsat:   noFeeLimitMsat,
-		},
+	ht.CompletePaymentRequests(
+		carol, []string{addInvoiceResp.PaymentRequest},
 	)
 
 	// Dave should get another notification.
-	invoiceNtfn, err = invSubscription.Recv()
-	require.NoError(t.t, err)
+	invoiceNtfn = ht.ReceiveInvoiceUpdate(invSubscription)
 
 	// The invoice should still be shown as settled, and also include the
 	// information about this newly generated setID, showing 2x the amount
 	// paid.
-	require.True(t.t, invoiceNtfn.Settled) // nolint:staticcheck
-	require.Equal(t.t, paymentAmt*2, int(invoiceNtfn.AmtPaidSat))
+	require.True(ht, invoiceNtfn.Settled)
+	require.Equal(ht, paymentAmt*2, int(invoiceNtfn.AmtPaidSat))
 
 	var secondSetID []byte
 	for setIDStr, ampState := range invoiceNtfn.AmpInvoiceState {
 		secondSetID, _ = hex.DecodeString(setIDStr)
-		require.Equal(t.t, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+		require.Equal(ht, lnrpc.InvoiceHTLCState_SETTLED,
+			ampState.State)
 	}
 
 	// The returned invoice should only include a single HTLC since we
 	// return the "projected" sub-invoice for a given setID.
-	require.Equal(t.t, 1, len(invoiceNtfn.Htlcs))
+	require.Equal(ht, 1, len(invoiceNtfn.Htlcs))
 
 	// However the AMP state index should show that there've been two
 	// repeated payments to this invoice so far.
-	require.Equal(t.t, 2, len(invoiceNtfn.AmpInvoiceState))
+	require.Equal(ht, 2, len(invoiceNtfn.AmpInvoiceState))
 
 	// Now we'll look up the invoice using the new LookupInvoice2 RPC call
 	// by the set ID of each of the invoices.
-	subInvoice1, err := dave.LookupInvoiceV2(ctxb, &invoicesrpc.LookupInvoiceMsg{
+	msg := &invoicesrpc.LookupInvoiceMsg{
 		InvoiceRef: &invoicesrpc.LookupInvoiceMsg_SetId{
 			SetId: firstSetID,
 		},
 		LookupModifier: invoicesrpc.LookupModifier_HTLC_SET_ONLY,
-	})
-	require.Nil(t.t, err)
-	subInvoice2, err := dave.LookupInvoiceV2(ctxb, &invoicesrpc.LookupInvoiceMsg{
+	}
+	subInvoice1 := dave.RPC.LookupInvoiceV2(msg)
+	msg = &invoicesrpc.LookupInvoiceMsg{
 		InvoiceRef: &invoicesrpc.LookupInvoiceMsg_SetId{
 			SetId: secondSetID,
 		},
 		LookupModifier: invoicesrpc.LookupModifier_HTLC_SET_ONLY,
-	})
-	require.Nil(t.t, err)
+	}
+	subInvoice2 := dave.RPC.LookupInvoiceV2(msg)
 
 	// Each invoice should only show a single HTLC present, as we passed
 	// the HTLC set only modifier.
-	require.Equal(t.t, 1, len(subInvoice1.Htlcs))
-	require.Equal(t.t, 1, len(subInvoice2.Htlcs))
+	require.Equal(ht, 1, len(subInvoice1.Htlcs))
+	require.Equal(ht, 1, len(subInvoice2.Htlcs))
 
 	// If we look up the same invoice, by its payment address, but now with
 	// the HTLC blank modifier, then none of them should be returned.
-	rootInvoice, err := dave.LookupInvoiceV2(ctxb, &invoicesrpc.LookupInvoiceMsg{
+	msg = &invoicesrpc.LookupInvoiceMsg{
 		InvoiceRef: &invoicesrpc.LookupInvoiceMsg_PaymentAddr{
 			PaymentAddr: addInvoiceResp.PaymentAddr,
 		},
 		LookupModifier: invoicesrpc.LookupModifier_HTLC_SET_BLANK,
-	})
-	require.Nil(t.t, err)
-	require.Equal(t.t, 0, len(rootInvoice.Htlcs))
+	}
+	rootInvoice := dave.RPC.LookupInvoiceV2(msg)
+	require.Equal(ht, 0, len(rootInvoice.Htlcs))
 
 	// If we look up the same invoice, by its payment address, but without
 	// that modified, then we should get all the relevant HTLCs.
-	rootInvoice, err = dave.LookupInvoiceV2(ctxb,
-		&invoicesrpc.LookupInvoiceMsg{
-			InvoiceRef: &invoicesrpc.LookupInvoiceMsg_PaymentAddr{
-				PaymentAddr: addInvoiceResp.PaymentAddr,
-			},
-		})
-	require.Nil(t.t, err)
-	require.Equal(t.t, 2, len(rootInvoice.Htlcs))
+	msg = &invoicesrpc.LookupInvoiceMsg{
+		InvoiceRef: &invoicesrpc.LookupInvoiceMsg_PaymentAddr{
+			PaymentAddr: addInvoiceResp.PaymentAddr,
+		},
+	}
+	rootInvoice = dave.RPC.LookupInvoiceV2(msg)
+	require.Equal(ht, 2, len(rootInvoice.Htlcs))
 
 	// Finally, we'll test that if we subscribe for notifications of
 	// settled invoices, we get a backlog, which includes the invoice we
@@ -379,29 +339,22 @@ func testSendPaymentAMPInvoiceRepeat(net *lntest.NetworkHarness,
 	req = &lnrpc.InvoiceSubscription{
 		SettleIndex: 1,
 	}
-	ctxc, cancelSubscription2 := context.WithCancel(ctxb)
-	invSub2, err := dave.SubscribeInvoices(ctxc, req)
-	require.NoError(t.t, err)
-	defer cancelSubscription2()
+	invSub2 := dave.RPC.SubscribeInvoices(req)
 
 	// The first invoice we get back should match the state of the invoice
 	// after our second payment: amt updated, but only a single HTLC shown
 	// through.
-	backlogInv, _ := invSub2.Recv()
-	require.Equal(t.t, 1, len(backlogInv.Htlcs))
-	require.Equal(t.t, 2, len(backlogInv.AmpInvoiceState))
-	require.True(t.t, backlogInv.Settled) // nolint:staticcheck
-	require.Equal(t.t, paymentAmt*2, int(backlogInv.AmtPaidSat))
+	backlogInv := ht.ReceiveInvoiceUpdate(invSub2)
+	require.Equal(ht, 1, len(backlogInv.Htlcs))
+	require.Equal(ht, 2, len(backlogInv.AmpInvoiceState))
+	require.True(ht, backlogInv.Settled)
+	require.Equal(ht, paymentAmt*2, int(backlogInv.AmtPaidSat))
 }
 
 // testSendPaymentAMP tests that we can send an AMP payment to a specified
 // destination using SendPaymentV2.
-func testSendPaymentAMP(net *lntest.NetworkHarness, t *harnessTest) {
-	ctxb := context.Background()
-
-	ctx := newMppTestContext(t, net)
-	defer ctx.shutdownNodes()
-
+func testSendPaymentAMP(ht *lntemp.HarnessTest) {
+	mts := newMppTestScenario(ht)
 	const paymentAmt = btcutil.Amount(300000)
 
 	// Set up a network with three different paths Alice <-> Bob. Channel
@@ -414,44 +367,37 @@ func testSendPaymentAMP(net *lntest.NetworkHarness, t *harnessTest) {
 	//      \              /
 	//       \__ Dave ____/
 	//
-	ctx.openChannel(ctx.carol, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.carol, 235000)
-	ctx.openChannel(ctx.dave, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.dave, 135000)
-	ctx.openChannel(ctx.eve, ctx.bob, 135000)
-	ctx.openChannel(ctx.carol, ctx.eve, 135000)
-
-	defer ctx.closeChannels()
-
-	ctx.waitForChannels()
+	mppReq := &mppOpenChannelRequest{
+		amtAliceCarol: 235000,
+		amtAliceDave:  135000,
+		amtCarolBob:   135000,
+		amtCarolEve:   135000,
+		amtDaveBob:    135000,
+		amtEveBob:     135000,
+	}
+	mts.openChannels(mppReq)
+	chanPointAliceDave := mts.channelPoints[1]
 
 	// Increase Dave's fee to make the test deterministic. Otherwise it
 	// would be unpredictable whether pathfinding would go through Charlie
 	// or Dave for the first shard.
-	_, err := ctx.dave.UpdateChannelPolicy(
-		context.Background(),
-		&lnrpc.PolicyUpdateRequest{
-			Scope:         &lnrpc.PolicyUpdateRequest_Global{Global: true},
-			BaseFeeMsat:   500000,
-			FeeRate:       0.001,
-			TimeLockDelta: 40,
-		},
-	)
-	if err != nil {
-		t.Fatalf("dave policy update: %v", err)
-	}
+	expectedPolicy := mts.updateDaveGlobalPolicy()
 
-	payment := sendAndAssertSuccess(
-		t, ctx.alice, &routerrpc.SendPaymentRequest{
-			Dest:           ctx.bob.PubKey[:],
-			Amt:            int64(paymentAmt),
-			FinalCltvDelta: chainreg.DefaultBitcoinTimeLockDelta,
-			TimeoutSeconds: 60,
-			FeeLimitMsat:   noFeeLimitMsat,
-			Amp:            true,
-		},
+	// Make sure Alice has heard it.
+	ht.AssertChannelPolicyUpdate(
+		mts.alice, mts.dave, expectedPolicy, chanPointAliceDave, false,
 	)
 
+	sendReq := &routerrpc.SendPaymentRequest{
+		Dest:           mts.bob.PubKey[:],
+		Amt:            int64(paymentAmt),
+		FinalCltvDelta: chainreg.DefaultBitcoinTimeLockDelta,
+		TimeoutSeconds: 60,
+		FeeLimitMsat:   noFeeLimitMsat,
+		Amp:            true,
+	}
+	payment := ht.SendPaymentAssertSettled(mts.alice, sendReq)
+
 	// Check that Alice split the payment in at least three shards. Because
 	// the hand-off of the htlc to the link is asynchronous (via a mailbox),
 	// there is some non-determinism in the process. Depending on whether
@@ -467,64 +413,55 @@ func testSendPaymentAMP(net *lntest.NetworkHarness, t *harnessTest) {
 	}
 
 	const minExpectedShards = 3
-	if succeeded < minExpectedShards {
-		t.Fatalf("expected at least %v shards, but got %v",
-			minExpectedShards, succeeded)
-	}
+	require.GreaterOrEqual(ht, succeeded, minExpectedShards,
+		"expected num of shards not reached")
 
-	// Fetch Bob's invoices.
-	invoiceResp, err := ctx.bob.ListInvoices(
-		ctxb, &lnrpc.ListInvoiceRequest{},
-	)
-	require.NoError(t.t, err)
-
-	// There should only be one invoice.
-	require.Equal(t.t, 1, len(invoiceResp.Invoices))
-	rpcInvoice := invoiceResp.Invoices[0]
+	// Fetch Bob's invoices. There should only be one invoice.
+	invoices := ht.AssertNumInvoices(mts.bob, 1)
+	rpcInvoice := invoices[0]
 
 	// Assert that the invoice is settled for the total payment amount and
 	// has the correct payment address.
-	require.True(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_SETTLED, rpcInvoice.State)
-	require.Equal(t.t, int64(paymentAmt), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
+	require.True(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_SETTLED, rpcInvoice.State)
+	require.Equal(ht, int64(paymentAmt), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
 
 	// Finally, assert that the same set id is recorded for each htlc, and
 	// that the preimage hash pair is valid.
 	var setID []byte
-	require.Equal(t.t, succeeded, len(rpcInvoice.Htlcs))
+	require.Equal(ht, succeeded, len(rpcInvoice.Htlcs))
 	for _, htlc := range rpcInvoice.Htlcs {
-		require.NotNil(t.t, htlc.Amp)
+		require.NotNil(ht, htlc.Amp)
 		if setID == nil {
 			setID = make([]byte, 32)
 			copy(setID, htlc.Amp.SetId)
 		}
-		require.Equal(t.t, setID, htlc.Amp.SetId)
+		require.Equal(ht, setID, htlc.Amp.SetId)
 
 		// Parse the child hash and child preimage, and assert they are
 		// well-formed.
 		childHash, err := lntypes.MakeHash(htlc.Amp.Hash)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 		childPreimage, err := lntypes.MakePreimage(htlc.Amp.Preimage)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 
 		// Assert that the preimage actually matches the hashes.
 		validPreimage := childPreimage.Matches(childHash)
-		require.True(t.t, validPreimage)
+		require.True(ht, validPreimage)
 	}
 
 	// The set ID we extract above should be shown in the final settled
 	// state.
 	ampState := rpcInvoice.AmpInvoiceState[hex.EncodeToString(setID)]
-	require.Equal(t.t, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+	require.Equal(ht, lnrpc.InvoiceHTLCState_SETTLED, ampState.State)
+
+	// Finally, close all channels.
+	mts.closeChannels()
 }
 
-func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
-	ctxb := context.Background()
-
-	ctx := newMppTestContext(t, net)
-	defer ctx.shutdownNodes()
-
+func testSendToRouteAMP(ht *lntemp.HarnessTest) {
+	mts := newMppTestScenario(ht)
 	const (
 		paymentAmt = btcutil.Amount(300000)
 		numShards  = 3
@@ -532,63 +469,50 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 		chanAmt    = shardAmt * 3 / 2
 	)
 
+	// Subscribe to bob's invoices.
+	req := &lnrpc.InvoiceSubscription{}
+	bobInvoiceSubscription := mts.bob.RPC.SubscribeInvoices(req)
+
 	// Set up a network with three different paths Alice <-> Bob.
 	//              _ Eve _
 	//             /       \
 	// Alice -- Carol ---- Bob
 	//      \              /
 	//       \__ Dave ____/
-	//
-	ctx.openChannel(ctx.carol, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.dave, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.alice, ctx.dave, chanAmt)
-	ctx.openChannel(ctx.eve, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.carol, ctx.eve, chanAmt)
-
-	// Since the channel Alice-> Carol will have to carry two
-	// shards, we make it larger.
-	ctx.openChannel(ctx.alice, ctx.carol, chanAmt+shardAmt)
-
-	defer ctx.closeChannels()
-
-	ctx.waitForChannels()
-
-	// Subscribe to bob's invoices.
-	req := &lnrpc.InvoiceSubscription{}
-	ctxc, cancelSubscription := context.WithCancel(ctxb)
-	bobInvoiceSubscription, err := ctx.bob.SubscribeInvoices(ctxc, req)
-	require.NoError(t.t, err)
-	defer cancelSubscription()
+	///
+	mppReq := &mppOpenChannelRequest{
+		// Since the channel Alice-> Carol will have to carry two
+		// shards, we make it larger.
+		amtAliceCarol: chanAmt + shardAmt,
+		amtAliceDave:  chanAmt,
+		amtCarolBob:   chanAmt,
+		amtCarolEve:   chanAmt,
+		amtDaveBob:    chanAmt,
+		amtEveBob:     chanAmt,
+	}
+	mts.openChannels(mppReq)
 
 	// We'll send shards along three routes from Alice.
-	sendRoutes := [numShards][]*lntest.HarnessNode{
-		{ctx.carol, ctx.bob},
-		{ctx.dave, ctx.bob},
-		{ctx.carol, ctx.eve, ctx.bob},
+	sendRoutes := [numShards][]*node.HarnessNode{
+		{mts.carol, mts.bob},
+		{mts.dave, mts.bob},
+		{mts.carol, mts.eve, mts.bob},
 	}
 
-	payAddr := make([]byte, 32)
-	_, err = rand.Read(payAddr)
-	require.NoError(t.t, err)
-
-	setID := make([]byte, 32)
-	_, err = rand.Read(setID)
-	require.NoError(t.t, err)
+	payAddr := ht.Random32Bytes()
+	setID := ht.Random32Bytes()
 
 	var sharer amp.Sharer
-	sharer, err = amp.NewSeedSharer()
-	require.NoError(t.t, err)
+	sharer, err := amp.NewSeedSharer()
+	require.NoError(ht, err)
 
 	childPreimages := make(map[lntypes.Preimage]uint32)
 	responses := make(chan *lnrpc.HTLCAttempt, len(sendRoutes))
 
 	// Define a closure for sending each of the three shards.
-	sendShard := func(i int, hops []*lntest.HarnessNode) {
+	sendShard := func(i int, hops []*node.HarnessNode) {
 		// Build a route for the specified hops.
-		r, err := ctx.buildRoute(ctxb, shardAmt, ctx.alice, hops)
-		if err != nil {
-			t.Fatalf("unable to build route: %v", err)
-		}
+		r := mts.buildRoute(shardAmt, mts.alice, hops)
 
 		// Set the MPP records to indicate this is a payment shard.
 		hop := r.Hops[len(r.Hops)-1]
@@ -602,7 +526,7 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 		if i < len(sendRoutes)-1 {
 			var left amp.Sharer
 			left, sharer, err = sharer.Split()
-			require.NoError(t.t, err)
+			require.NoError(ht, err)
 
 			child = left.Child(uint32(i))
 		} else {
@@ -622,15 +546,10 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 			Route:       r,
 		}
 
-		// We'll send all shards in their own goroutine, since SendToRoute will
-		// block as long as the payment is in flight.
+		// We'll send all shards in their own goroutine, since
+		// SendToRoute will block as long as the payment is in flight.
 		go func() {
-			ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-			resp, err := ctx.alice.RouterClient.SendToRouteV2(ctxt, sendReq)
-			if err != nil {
-				t.Fatalf("unable to send payment: %v", err)
-			}
-
+			resp := mts.alice.RPC.SendToRouteV2(sendReq)
 			responses <- resp
 		}()
 	}
@@ -640,21 +559,21 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 
 	// Ensure we get a notification of the invoice being added by Bob.
 	rpcInvoice, err := bobInvoiceSubscription.Recv()
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
-	require.False(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_OPEN, rpcInvoice.State)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(0), rpcInvoice.AmtPaidMsat)
-	require.Equal(t.t, payAddr, rpcInvoice.PaymentAddr)
+	require.False(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_OPEN, rpcInvoice.State)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(0), rpcInvoice.AmtPaidMsat)
+	require.Equal(ht, payAddr, rpcInvoice.PaymentAddr)
 
-	require.Equal(t.t, 0, len(rpcInvoice.Htlcs))
+	require.Equal(ht, 0, len(rpcInvoice.Htlcs))
 
 	sendShard(1, sendRoutes[1])
 	sendShard(2, sendRoutes[2])
 
 	// Assert that all of the child preimages are unique.
-	require.Equal(t.t, len(sendRoutes), len(childPreimages))
+	require.Equal(ht, len(sendRoutes), len(childPreimages))
 
 	// Make a copy of the childPreimages map for validating the resulting
 	// invoice.
@@ -665,24 +584,23 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 
 	// Wait for all responses to be back, and check that they all
 	// succeeded.
+	timer := time.After(defaultTimeout)
 	for range sendRoutes {
 		var resp *lnrpc.HTLCAttempt
 		select {
 		case resp = <-responses:
-		case <-time.After(defaultTimeout):
-			t.Fatalf("response not received")
+		case <-timer:
+			require.Fail(ht, "response not received")
 		}
 
-		if resp.Failure != nil {
-			t.Fatalf("received payment failure : %v", resp.Failure)
-		}
+		require.Nil(ht, resp.Failure, "received payment failure")
 
 		preimage, err := lntypes.MakePreimage(resp.Preimage)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 
 		// Assert that the response includes one of our child preimages.
 		_, ok := childPreimages[preimage]
-		require.True(t.t, ok)
+		require.True(ht, ok)
 
 		// Remove this preimage from out set so that we ensure all
 		// responses have a unique child preimage.
@@ -692,109 +610,51 @@ func testSendToRouteAMP(net *lntest.NetworkHarness, t *harnessTest) {
 
 	// There should now be a settle event for the invoice.
 	rpcInvoice, err = bobInvoiceSubscription.Recv()
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	// Also fetch Bob's invoice from ListInvoices and assert it is equal to
 	// the one received via the subscription.
-	invoiceResp, err := ctx.bob.ListInvoices(
-		ctxb, &lnrpc.ListInvoiceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Equal(t.t, 1, len(invoiceResp.Invoices))
-	assertInvoiceEqual(t.t, rpcInvoice, invoiceResp.Invoices[0])
+	invoices := ht.AssertNumInvoices(mts.bob, 1)
+	ht.AssertInvoiceEqual(rpcInvoice, invoices[0])
 
 	// Assert that the invoice is settled for the total payment amount and
 	// has the correct payment address.
-	require.True(t.t, rpcInvoice.Settled) // nolint:staticcheck
-	require.Equal(t.t, lnrpc.Invoice_SETTLED, rpcInvoice.State)
-	require.Equal(t.t, int64(paymentAmt), rpcInvoice.AmtPaidSat)
-	require.Equal(t.t, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
-	require.Equal(t.t, payAddr, rpcInvoice.PaymentAddr)
+	require.True(ht, rpcInvoice.Settled)
+	require.Equal(ht, lnrpc.Invoice_SETTLED, rpcInvoice.State)
+	require.Equal(ht, int64(paymentAmt), rpcInvoice.AmtPaidSat)
+	require.Equal(ht, int64(paymentAmt*1000), rpcInvoice.AmtPaidMsat)
+	require.Equal(ht, payAddr, rpcInvoice.PaymentAddr)
 
 	// Finally, assert that the proper set id is recorded for each htlc, and
 	// that the preimage hash pair is valid.
-	require.Equal(t.t, numShards, len(rpcInvoice.Htlcs))
+	require.Equal(ht, numShards, len(rpcInvoice.Htlcs))
 	for _, htlc := range rpcInvoice.Htlcs {
-		require.NotNil(t.t, htlc.Amp)
-		require.Equal(t.t, setID, htlc.Amp.SetId)
+		require.NotNil(ht, htlc.Amp)
+		require.Equal(ht, setID, htlc.Amp.SetId)
 
 		// Parse the child hash and child preimage, and assert they are
 		// well-formed.
 		childHash, err := lntypes.MakeHash(htlc.Amp.Hash)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 		childPreimage, err := lntypes.MakePreimage(htlc.Amp.Preimage)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 
 		// Assert that the preimage actually matches the hashes.
 		validPreimage := childPreimage.Matches(childHash)
-		require.True(t.t, validPreimage)
+		require.True(ht, validPreimage)
 
 		// Assert that the HTLC includes one of our child preimages.
 		childIndex, ok := childPreimages[childPreimage]
-		require.True(t.t, ok)
+		require.True(ht, ok)
 
 		// Assert that the correct child index is reflected.
-		require.Equal(t.t, childIndex, htlc.Amp.ChildIndex)
+		require.Equal(ht, childIndex, htlc.Amp.ChildIndex)
 
 		// Remove this preimage from our set so that we ensure all HTLCs
 		// have a unique child preimage.
 		delete(childPreimages, childPreimage)
 	}
-}
-
-// assertInvoiceEqual asserts that two lnrpc.Invoices are equivalent. A custom
-// comparison function is defined for these tests, since proto message returned
-// from unary and streaming RPCs (as of protobuf 1.23.0 and grpc 1.29.1) aren't
-// consistent with the private fields set on the messages. As a result, we avoid
-// using require.Equal and test only the actual data members.
-func assertInvoiceEqual(t *testing.T, a, b *lnrpc.Invoice) {
-	t.Helper()
-
-	// Ensure the HTLCs are sorted properly before attempting to compare.
-	sort.Slice(a.Htlcs, func(i, j int) bool {
-		return a.Htlcs[i].ChanId < a.Htlcs[j].ChanId
-	})
-	sort.Slice(b.Htlcs, func(i, j int) bool {
-		return b.Htlcs[i].ChanId < b.Htlcs[j].ChanId
-	})
-
-	require.Equal(t, a.Memo, b.Memo)
-	require.Equal(t, a.RPreimage, b.RPreimage)
-	require.Equal(t, a.RHash, b.RHash)
-	require.Equal(t, a.Value, b.Value)
-	require.Equal(t, a.ValueMsat, b.ValueMsat)
-	require.Equal(t, a.CreationDate, b.CreationDate)
-	require.Equal(t, a.SettleDate, b.SettleDate)
-	require.Equal(t, a.PaymentRequest, b.PaymentRequest)
-	require.Equal(t, a.DescriptionHash, b.DescriptionHash)
-	require.Equal(t, a.Expiry, b.Expiry)
-	require.Equal(t, a.FallbackAddr, b.FallbackAddr)
-	require.Equal(t, a.CltvExpiry, b.CltvExpiry)
-	require.Equal(t, a.RouteHints, b.RouteHints)
-	require.Equal(t, a.Private, b.Private)
-	require.Equal(t, a.AddIndex, b.AddIndex)
-	require.Equal(t, a.SettleIndex, b.SettleIndex)
-	require.Equal(t, a.AmtPaidSat, b.AmtPaidSat)
-	require.Equal(t, a.AmtPaidMsat, b.AmtPaidMsat)
-	require.Equal(t, a.State, b.State)
-	require.Equal(t, a.Features, b.Features)
-	require.Equal(t, a.IsKeysend, b.IsKeysend)
-	require.Equal(t, a.PaymentAddr, b.PaymentAddr)
-	require.Equal(t, a.IsAmp, b.IsAmp)
-
-	require.Equal(t, len(a.Htlcs), len(b.Htlcs))
-	for i := range a.Htlcs {
-		htlcA, htlcB := a.Htlcs[i], b.Htlcs[i]
-		require.Equal(t, htlcA.ChanId, htlcB.ChanId)
-		require.Equal(t, htlcA.HtlcIndex, htlcB.HtlcIndex)
-		require.Equal(t, htlcA.AmtMsat, htlcB.AmtMsat)
-		require.Equal(t, htlcA.AcceptHeight, htlcB.AcceptHeight)
-		require.Equal(t, htlcA.AcceptTime, htlcB.AcceptTime)
-		require.Equal(t, htlcA.ResolveTime, htlcB.ResolveTime)
-		require.Equal(t, htlcA.ExpiryHeight, htlcB.ExpiryHeight)
-		require.Equal(t, htlcA.State, htlcB.State)
-		require.Equal(t, htlcA.CustomRecords, htlcB.CustomRecords)
-		require.Equal(t, htlcA.MppTotalAmtMsat, htlcB.MppTotalAmtMsat)
-		require.Equal(t, htlcA.Amp, htlcB.Amp)
-	}
+
+	// Finally, close all channels.
+	mts.closeChannels()
 }

lntest/itest/lnd_custom_message.go

@@ -1,13 +1,11 @@
 package itest
 
 import (
-	"context"
 	"fmt"
-	"sync"
 	"time"
 
 	"github.com/lightningnetwork/lnd/lnrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/stretchr/testify/require"
 )
@@ -15,16 +13,8 @@ import (
 // testCustomMessage tests sending and receiving of overridden custom message
 // types (within the message type range usually reserved for protocol messages)
 // via the send and subscribe custom message APIs.
-func testCustomMessage(net *lntest.NetworkHarness, t *harnessTest) {
-	ctx, cancel := context.WithCancel(context.Background())
-	var wg sync.WaitGroup
-
-	// At the end of our test, cancel our context and wait for all
-	// goroutines to exit.
-	defer func() {
-		cancel()
-		wg.Wait()
-	}()
+func testCustomMessage(ht *lntemp.HarnessTest) {
+	alice, bob := ht.Alice, ht.Bob
 
 	var (
 		overrideType1  uint32 = 554
@@ -34,28 +24,19 @@ func testCustomMessage(net *lntest.NetworkHarness, t *harnessTest) {
 
 	// Update Alice to accept custom protocol messages with type 1 but do
 	// not allow Bob to handle them yet.
-	net.Alice.Cfg.ExtraArgs = append(
-		net.Alice.Cfg.ExtraArgs,
+	extraArgs := []string{
 		fmt.Sprintf(msgOverrideArg, overrideType1),
-	)
-	require.NoError(t.t, net.RestartNode(net.Alice, nil, nil))
-
-	// Wait for Alice's server to be active after the restart before we
-	// try to subscribe to our message stream.
-	require.NoError(t.t, net.Alice.WaitUntilServerActive())
+	}
+	ht.RestartNodeWithExtraArgs(alice, extraArgs)
 
 	// Subscribe Alice to custom messages before we send any, so that we
 	// don't miss any.
-	msgClient, err := net.Alice.LightningClient.SubscribeCustomMessages(
-		ctx, &lnrpc.SubscribeCustomMessagesRequest{},
-	)
-	require.NoError(t.t, err, "alice could not subscribe")
+	msgClient, cancel := alice.RPC.SubscribeCustomMessages()
+	defer cancel()
 
 	// Create a channel to receive custom messages on.
 	messages := make(chan *lnrpc.CustomMessage)
-	wg.Add(1)
 	go func() {
-		defer wg.Done()
 		for {
 			// If we fail to receive, just exit. The test should
 			// fail elsewhere if it doesn't get a message that it
@@ -69,120 +50,108 @@ func testCustomMessage(net *lntest.NetworkHarness, t *harnessTest) {
 			// test is shutting down.
 			select {
 			case messages <- msg:
-			case <-ctx.Done():
+			case <-ht.Context().Done():
 				return
 			}
 		}
 	}()
 
 	// Connect alice and bob so that they can exchange messages.
-	net.EnsureConnected(t.t, net.Alice, net.Bob)
+	ht.EnsureConnected(alice, bob)
 
 	// Create a custom message that is within our allowed range.
 	msgType := uint32(lnwire.CustomTypeStart + 1)
 	msgData := []byte{1, 2, 3}
 
 	// Send it from Bob to Alice.
-	ctxt, _ := context.WithTimeout(ctx, defaultTimeout)
-	_, err = net.Bob.LightningClient.SendCustomMessage(
-		ctxt, &lnrpc.SendCustomMessageRequest{
-			Peer: net.Alice.PubKey[:],
-			Type: msgType,
-			Data: msgData,
-		},
-	)
-	require.NoError(t.t, err, "bob could not send")
+	bobMsg := &lnrpc.SendCustomMessageRequest{
+		Peer: alice.PubKey[:],
+		Type: msgType,
+		Data: msgData,
+	}
+	bob.RPC.SendCustomMessage(bobMsg)
 
-	// Wait for Alice to receive the message. It should come through because
-	// it is within our allowed range.
+	// Wait for Alice to receive the message. It should come through
+	// because it is within our allowed range.
 	select {
 	case msg := <-messages:
-		// Check our type and data and (sanity) check the peer we got it
-		// from.
-		require.Equal(t.t, msgType, msg.Type, "first msg type wrong")
-		require.Equal(t.t, msgData, msg.Data, "first msg data wrong")
-		require.Equal(t.t, net.Bob.PubKey[:], msg.Peer, "first msg "+
+		// Check our type and data and (sanity) check the peer we got
+		// it from.
+		require.Equal(ht, msgType, msg.Type, "first msg type wrong")
+		require.Equal(ht, msgData, msg.Data, "first msg data wrong")
+		require.Equal(ht, bob.PubKey[:], msg.Peer, "first msg "+
 			"peer wrong")
 
 	case <-time.After(defaultTimeout):
-		t.t.Fatalf("alice did not receive first custom message: %v",
+		ht.Fatalf("alice did not receive first custom message: %v",
 			msgType)
 	}
 
 	// Try to send a message from Bob to Alice which has a message type
 	// outside of the custom type range and assert that it fails.
-	ctxt, _ = context.WithTimeout(ctx, defaultTimeout)
-	_, err = net.Bob.LightningClient.SendCustomMessage(
-		ctxt, &lnrpc.SendCustomMessageRequest{
-			Peer: net.Alice.PubKey[:],
-			Type: overrideType1,
-			Data: msgData,
-		},
-	)
-	require.Error(t.t, err, "bob should not be able to send type 1")
+	bobMsg = &lnrpc.SendCustomMessageRequest{
+		Peer: alice.PubKey[:],
+		Type: overrideType1,
+		Data: msgData,
+	}
+	_, err := bob.RPC.LN.SendCustomMessage(ht.Context(), bobMsg)
+	require.Error(ht, err, "bob should not be able to send type 1")
 
 	// Now, restart Bob with the ability to send two different custom
 	// protocol messages.
-	net.Bob.Cfg.ExtraArgs = append(
-		net.Bob.Cfg.ExtraArgs,
+	extraArgs = []string{
 		fmt.Sprintf(msgOverrideArg, overrideType1),
 		fmt.Sprintf(msgOverrideArg, overrideType2),
-	)
-	require.NoError(t.t, net.RestartNode(net.Bob, nil, nil))
+	}
+	ht.RestartNodeWithExtraArgs(bob, extraArgs)
 
 	// Make sure Bob and Alice are connected after his restart.
-	net.EnsureConnected(t.t, net.Alice, net.Bob)
+	ht.EnsureConnected(alice, bob)
 
 	// Send a message from Bob to Alice with a type that Bob is allowed to
 	// send, but Alice will not handle as a custom message.
-	ctxt, _ = context.WithTimeout(ctx, defaultTimeout)
-	_, err = net.Bob.LightningClient.SendCustomMessage(
-		ctxt, &lnrpc.SendCustomMessageRequest{
-			Peer: net.Alice.PubKey[:],
-			Type: overrideType2,
-			Data: msgData,
-		},
-	)
-	require.NoError(t.t, err, "bob should be able to send type 2")
+	bobMsg = &lnrpc.SendCustomMessageRequest{
+		Peer: alice.PubKey[:],
+		Type: overrideType2,
+		Data: msgData,
+	}
+	bob.RPC.SendCustomMessage(bobMsg)
 
 	// Do a quick check that Alice did not receive this message in her
-	// stream. Note that this is an instant check, so could miss the message
-	// being received. We'll also check below that she didn't get it, this
-	// is just a sanity check.
+	// stream. Note that this is an instant check, so could miss the
+	// message being received. We'll also check below that she didn't get
+	// it, this is just a sanity check.
 	select {
 	case msg := <-messages:
-		t.t.Fatalf("unexpected message: %v", msg)
+		ht.Fatalf("unexpected message: %v", msg)
 	default:
 	}
 
 	// Finally, send a custom message with a type that Bob is allowed to
 	// send and Alice is configured to receive.
-	ctxt, _ = context.WithTimeout(ctx, defaultTimeout)
-	_, err = net.Bob.LightningClient.SendCustomMessage(
-		ctxt, &lnrpc.SendCustomMessageRequest{
-			Peer: net.Alice.PubKey[:],
-			Type: overrideType1,
-			Data: msgData,
-		},
-	)
-	require.NoError(t.t, err, "bob should be able to send type 1")
+	bobMsg = &lnrpc.SendCustomMessageRequest{
+		Peer: alice.PubKey[:],
+		Type: overrideType1,
+		Data: msgData,
+	}
+	bob.RPC.SendCustomMessage(bobMsg)
 
 	// Wait to receive a message from Bob. This check serves to ensure that
 	// our message type 1 was delivered, and assert that the preceding one
-	// was not (we could have missed it in our check above). When we receive
-	// the second message, we know that the first one did not go through,
-	// because we expect our messages to deliver in order.
+	// was not (we could have missed it in our check above). When we
+	// receive the second message, we know that the first one did not go
+	// through, because we expect our messages to deliver in order.
 	select {
 	case msg := <-messages:
-		// Check our type and data and (sanity) check the peer we got it
-		// from.
-		require.Equal(t.t, overrideType1, msg.Type, "second message "+
+		// Check our type and data and (sanity) check the peer we got
+		// it from.
+		require.Equal(ht, overrideType1, msg.Type, "second message "+
 			"type")
-		require.Equal(t.t, msgData, msg.Data, "second message data")
-		require.Equal(t.t, net.Bob.PubKey[:], msg.Peer, "second "+
+		require.Equal(ht, msgData, msg.Data, "second message data")
+		require.Equal(ht, bob.PubKey[:], msg.Peer, "second "+
 			"message peer")
 
 	case <-time.After(defaultTimeout):
-		t.t.Fatalf("alice did not receive second custom message")
+		ht.Fatalf("alice did not receive second custom message")
 	}
 }

lntest/itest/lnd_forward_interceptor_test.go

@@ -1,19 +1,18 @@
 package itest
 
 import (
-	"context"
-	"encoding/hex"
 	"fmt"
-	"sync"
+	"strings"
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil"
-	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainreg"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/lightningnetwork/lnd/lntest/wait"
+	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/stretchr/testify/require"
 	"google.golang.org/grpc/codes"
@@ -35,163 +34,145 @@ type interceptorTestCase struct {
 
 // testForwardInterceptorDedupHtlc tests that upon reconnection, duplicate
 // HTLCs aren't re-notified using the HTLC interceptor API.
-func testForwardInterceptorDedupHtlc(net *lntest.NetworkHarness, t *harnessTest) {
+func testForwardInterceptorDedupHtlc(ht *lntemp.HarnessTest) {
 	// Initialize the test context with 3 connected nodes.
-	alice := net.NewNode(t.t, "alice", nil)
-	defer shutdownAndAssert(net, t, alice)
+	ts := newInterceptorTestScenario(ht)
 
-	bob := net.NewNode(t.t, "bob", nil)
-	defer shutdownAndAssert(net, t, bob)
-
-	carol := net.NewNode(t.t, "carol", nil)
-	defer shutdownAndAssert(net, t, carol)
-
-	tc := newInterceptorTestContext(t, net, alice, bob, carol)
-
-	const (
-		chanAmt = btcutil.Amount(300000)
-	)
+	alice, bob, carol := ts.alice, ts.bob, ts.carol
 
 	// Open and wait for channels.
-	tc.openChannel(tc.alice, tc.bob, chanAmt)
-	tc.openChannel(tc.bob, tc.carol, chanAmt)
-	defer tc.closeChannels()
-	tc.waitForChannels()
+	const chanAmt = btcutil.Amount(300000)
+	p := lntemp.OpenChannelParams{Amt: chanAmt}
+	reqs := []*lntemp.OpenChannelRequest{
+		{Local: alice, Remote: bob, Param: p},
+		{Local: bob, Remote: carol, Param: p},
+	}
+	resp := ht.OpenMultiChannelsAsync(reqs)
+	cpAB, cpBC := resp[0], resp[1]
 
-	ctxb := context.Background()
-	ctxt, cancelInterceptor := context.WithCancel(ctxb)
-	interceptor, err := tc.bob.RouterClient.HtlcInterceptor(ctxt)
-	require.NoError(tc.t.t, err, "failed to create HtlcInterceptor")
+	// Make sure Alice is aware of channel Bob=>Carol.
+	ht.AssertTopologyChannelOpen(alice, cpBC)
 
-	addResponse, err := tc.carol.AddInvoice(ctxb, &lnrpc.Invoice{
-		ValueMsat: 1000,
-	})
-	require.NoError(tc.t.t, err, "unable to add invoice")
+	// Connect the interceptor.
+	interceptor, cancelInterceptor := bob.RPC.HtlcInterceptor()
 
-	invoice, err := tc.carol.LookupInvoice(ctxb, &lnrpc.PaymentHash{
-		RHashStr: hex.EncodeToString(addResponse.RHash),
-	})
-	require.NoError(tc.t.t, err, "unable to find invoice")
+	// Prepare the test cases.
+	req := &lnrpc.Invoice{ValueMsat: 1000}
+	addResponse := carol.RPC.AddInvoice(req)
+	invoice := carol.RPC.LookupInvoice(addResponse.RHash)
+	tc := &interceptorTestCase{
+		amountMsat: 1000,
+		invoice:    invoice,
+		payAddr:    invoice.PaymentAddr,
+	}
+
+	// We initiate a payment from Alice.
+	done := make(chan struct{})
+	go func() {
+		// Signal that all the payments have been sent.
+		defer close(done)
+
+		ts.sendPaymentAndAssertAction(tc)
+	}()
 
 	// We start the htlc interceptor with a simple implementation that
 	// saves all intercepted packets. These packets are held to simulate a
 	// pending payment.
-	interceptedPacketstMap := &sync.Map{}
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		for {
-			packet, err := interceptor.Recv()
-			if err != nil {
-				// If it is just the error result of the
-				// context cancellation the we exit silently.
-				status, ok := status.FromError(err)
-				if ok && status.Code() == codes.Canceled {
-					return
-				}
-
-				// Otherwise it an unexpected error, we fail
-				// the test.
-				require.NoError(
-					tc.t.t, err,
-					"unexpected error in interceptor.Recv()",
-				)
-				return
-			}
-			interceptedPacketstMap.Store(
-				packet.IncomingCircuitKey.HtlcId, packet,
-			)
-		}
-	}()
-
-	// We initiate a payment from Alice.
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		_, _ = tc.sendAliceToCarolPayment(
-			ctxb, 1000,
-			invoice.RHash, invoice.PaymentAddr,
-		)
-	}()
+	packet := ht.ReceiveHtlcInterceptor(interceptor)
 
 	// Here we should wait for the channel to contain a pending htlc, and
 	// also be shown as being active.
-	err = wait.Predicate(func() bool {
-		channels, err := tc.bob.ListChannels(ctxt, &lnrpc.ListChannelsRequest{
-			ActiveOnly: true,
-			Peer:       tc.alice.PubKey[:],
-		})
-		if err != nil {
-			return false
+	err := wait.NoError(func() error {
+		channel := ht.QueryChannelByChanPoint(bob, cpAB)
+
+		if len(channel.PendingHtlcs) == 0 {
+			return fmt.Errorf("expect alice <> bob channel to " +
+				"have pending htlcs")
 		}
-		if len(channels.Channels) == 0 {
-			return false
+		if channel.Active {
+			return nil
 		}
 
-		aliceChan := channels.Channels[0]
-		if len(aliceChan.PendingHtlcs) == 0 {
-			return false
-		}
-		return aliceChan.Active
+		return fmt.Errorf("channel not active")
 	}, defaultTimeout)
 	require.NoError(
-		tc.t.t, err, "alice <> bob channel pending htlc never arrived",
+		ht, err, "alice <> bob channel pending htlc never arrived",
 	)
 
 	// At this point we want to make bob's link send all pending htlcs to
 	// the switch again. We force this behavior by disconnecting and
 	// connecting to the peer.
-	if err := tc.net.DisconnectNodes(tc.bob, tc.alice); err != nil {
-		tc.t.Fatalf("failed to disconnect alice and bob")
-	}
-	tc.net.EnsureConnected(tc.t.t, tc.bob, tc.alice)
+	ht.DisconnectNodes(bob, alice)
+	ht.EnsureConnected(bob, alice)
 
 	// Here we wait for the channel to be active again.
-	err = wait.Predicate(func() bool {
-		req := &lnrpc.ListChannelsRequest{
-			ActiveOnly: true,
-			Peer:       tc.alice.PubKey[:],
-		}
-
-		channels, err := tc.bob.ListChannels(ctxt, req)
-		return err == nil && len(channels.Channels) > 0
-	}, defaultTimeout)
-	require.NoError(
-		tc.t.t, err, "alice <> bob channel didn't re-activate",
-	)
+	ht.AssertChannelExists(bob, cpAB)
 
 	// Now that the channel is active we make sure the test passes as
 	// expected.
-	payments, err := tc.alice.ListPayments(ctxb, &lnrpc.ListPaymentsRequest{
-		IncludeIncomplete: true,
-	})
-	require.NoError(tc.t.t, err, "failed to fetch payment")
 
 	// We expect one in flight payment since we held the htlcs.
-	require.Equal(tc.t.t, len(payments.Payments), 1)
-	require.Equal(tc.t.t, payments.Payments[0].Status, lnrpc.Payment_IN_FLIGHT)
-
-	// We now fail all htlcs to cancel the payment.
-	packetsCount := 0
-	interceptedPacketstMap.Range(func(_, packet interface{}) bool {
-		p := packet.(*routerrpc.ForwardHtlcInterceptRequest)
-		_ = interceptor.Send(&routerrpc.ForwardHtlcInterceptResponse{
-			IncomingCircuitKey: p.IncomingCircuitKey,
-			Action:             routerrpc.ResolveHoldForwardAction_FAIL,
-		})
-		packetsCount++
-		return true
-	})
+	var preimage lntypes.Preimage
+	copy(preimage[:], invoice.RPreimage)
+	ht.AssertPaymentStatus(alice, preimage, lnrpc.Payment_IN_FLIGHT)
 
 	// At this point if we have more than one held htlcs then we should
-	// fail.  This means we hold the same htlc twice which is a risk we
-	// want to eliminate. If we don't have the same htlc twice in theory we
-	// can cancel one and settle the other by mistake.
-	require.Equal(tc.t.t, packetsCount, 1)
+	// fail. This means we hold the same htlc twice which is a risk we want
+	// to eliminate. If we don't have the same htlc twice in theory we can
+	// cancel one and settle the other by mistake.
+	errDone := make(chan struct{})
+	go func() {
+		defer close(errDone)
 
+		_, err := interceptor.Recv()
+		require.Error(ht, err, "expected an error from interceptor")
+
+		status, ok := status.FromError(err)
+		switch {
+		// If it is just the error result of the context cancellation
+		// the we exit silently.
+		case ok && status.Code() == codes.Canceled:
+			fallthrough
+
+		// When the test ends, during the node's shutdown it will close
+		// the connection.
+		case strings.Contains(err.Error(), "closed network connection"):
+			fallthrough
+
+		case strings.Contains(err.Error(), "EOF"):
+			return
+		}
+
+		// Otherwise we receive an unexpected error.
+		require.Failf(ht, "interceptor", "unexpected err: %v", err)
+	}()
+
+	// We now fail all htlcs to cancel the payment.
+	err = interceptor.Send(&routerrpc.ForwardHtlcInterceptResponse{
+		IncomingCircuitKey: packet.IncomingCircuitKey,
+		Action:             routerrpc.ResolveHoldForwardAction_FAIL,
+	})
+	require.NoError(ht, err, "failed to send request")
+
+	// Cancel the context, which will disconnect the above interceptor.
 	cancelInterceptor()
-	wg.Wait()
+
+	// Make sure all goroutines are finished.
+	select {
+	case <-done:
+	case <-time.After(defaultTimeout):
+		require.Fail(ht, "timeout waiting for sending payment")
+	}
+
+	select {
+	case <-errDone:
+	case <-time.After(defaultTimeout):
+		require.Fail(ht, "timeout waiting for interceptor error")
+	}
+
+	// Finally, close channels.
+	ht.CloseChannel(alice, cpAB)
+	ht.CloseChannel(bob, cpBC)
 }
 
 // testForwardInterceptorBasic tests the forward interceptor RPC layer.
@@ -204,265 +185,191 @@ func testForwardInterceptorDedupHtlc(net *lntest.NetworkHarness, t *harnessTest)
 //  3. Intercepted held htlcs result in no payment (invoice is not settled).
 //  4. When Interceptor disconnects it resumes all held htlcs, which result in
 //     valid payment (invoice is settled).
-func testForwardInterceptorBasic(net *lntest.NetworkHarness, t *harnessTest) {
-	// Initialize the test context with 3 connected nodes.
-	alice := net.NewNode(t.t, "alice", nil)
-	defer shutdownAndAssert(net, t, alice)
+func testForwardInterceptorBasic(ht *lntemp.HarnessTest) {
+	ts := newInterceptorTestScenario(ht)
 
-	bob := net.NewNode(t.t, "bob", nil)
-	defer shutdownAndAssert(net, t, bob)
-
-	carol := net.NewNode(t.t, "carol", nil)
-	defer shutdownAndAssert(net, t, carol)
-
-	testContext := newInterceptorTestContext(t, net, alice, bob, carol)
-
-	const (
-		chanAmt = btcutil.Amount(300000)
-	)
+	alice, bob, carol := ts.alice, ts.bob, ts.carol
 
 	// Open and wait for channels.
-	testContext.openChannel(testContext.alice, testContext.bob, chanAmt)
-	testContext.openChannel(testContext.bob, testContext.carol, chanAmt)
-	defer testContext.closeChannels()
-	testContext.waitForChannels()
+	const chanAmt = btcutil.Amount(300000)
+	p := lntemp.OpenChannelParams{Amt: chanAmt}
+	reqs := []*lntemp.OpenChannelRequest{
+		{Local: alice, Remote: bob, Param: p},
+		{Local: bob, Remote: carol, Param: p},
+	}
+	resp := ht.OpenMultiChannelsAsync(reqs)
+	cpAB, cpBC := resp[0], resp[1]
+
+	// Make sure Alice is aware of channel Bob=>Carol.
+	ht.AssertTopologyChannelOpen(alice, cpBC)
 
 	// Connect the interceptor.
-	ctxb := context.Background()
-	ctxt, cancelInterceptor := context.WithTimeout(ctxb, defaultTimeout)
-	interceptor, err := testContext.bob.RouterClient.HtlcInterceptor(ctxt)
-	require.NoError(t.t, err, "failed to create HtlcInterceptor")
+	interceptor, cancelInterceptor := bob.RPC.HtlcInterceptor()
 
 	// Prepare the test cases.
-	testCases := testContext.prepareTestCases()
+	testCases := ts.prepareTestCases()
 
-	// A channel for the interceptor go routine to send the requested packets.
-	interceptedChan := make(chan *routerrpc.ForwardHtlcInterceptRequest,
-		len(testCases))
-
-	// Run the interceptor loop in its own go routine.
-	var wg sync.WaitGroup
-	wg.Add(1)
+	// For each test case make sure we initiate a payment from Alice to
+	// Carol routed through Bob. For each payment we also test its final
+	// status according to the interceptorAction specified in the test
+	// case.
+	done := make(chan struct{})
 	go func() {
-		defer wg.Done()
-		for {
-			request, err := interceptor.Recv()
-			if err != nil {
-				// If it is  just the error result of the context cancellation
-				// the we exit silently.
-				status, ok := status.FromError(err)
-				if ok && status.Code() == codes.Canceled {
-					return
-				}
-				// Otherwise it an unexpected error, we fail the test.
-				require.NoError(t.t, err, "unexpected error in interceptor.Recv()")
-				return
-			}
-			interceptedChan <- request
-		}
-	}()
+		// Signal that all the payments have been sent.
+		defer close(done)
 
-	// For each test case make sure we initiate a payment from Alice to Carol
-	// routed through Bob. For each payment we also test its final status
-	// according to the interceptorAction specified in the test case.
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
 		for _, tc := range testCases {
-			attempt, err := testContext.sendAliceToCarolPayment(
-				context.Background(), tc.invoice.ValueMsat,
-				tc.invoice.RHash, tc.payAddr,
-			)
-
-			if t.t.Failed() {
-				return
-			}
-			if err != nil {
-				require.NoError(t.t, err, "failed to send payment")
-			}
-
-			switch tc.interceptorAction {
-			// For 'fail' interceptor action we make sure the payment failed.
-			case routerrpc.ResolveHoldForwardAction_FAIL:
-				require.Equal(t.t, lnrpc.HTLCAttempt_FAILED,
-					attempt.Status, "expected payment to fail")
-
-				// Assert that we get a temporary channel
-				// failure which has a channel update.
-				require.NotNil(t.t, attempt.Failure)
-				require.NotNil(t.t, attempt.Failure.ChannelUpdate)
-
-				require.Equal(t.t,
-					lnrpc.Failure_TEMPORARY_CHANNEL_FAILURE,
-					attempt.Failure.Code)
-
-			// For settle and resume we make sure the payment is successful.
-			case routerrpc.ResolveHoldForwardAction_SETTLE:
-				fallthrough
-
-			case routerrpc.ResolveHoldForwardAction_RESUME:
-				require.Equal(t.t, lnrpc.HTLCAttempt_SUCCEEDED,
-					attempt.Status, "expected payment to succeed")
-			}
+			attempt := ts.sendPaymentAndAssertAction(tc)
+			ts.assertAction(tc, attempt)
 		}
 	}()
 
-	// We make sure here the interceptor has processed all packets before we
-	// check the payment statuses.
-	for i := 0; i < len(testCases); i++ {
-		select {
-		case request := <-interceptedChan:
-			// Assert sanity of informational packet data.
-			require.NotZero(t.t, request.OutgoingRequestedChanId)
-			require.NotZero(t.t, request.IncomingExpiry)
-			require.NotZero(t.t, request.IncomingAmountMsat)
+	// We make sure here the interceptor has processed all packets before
+	// we check the payment statuses.
+	for _, tc := range testCases {
+		request := ht.ReceiveHtlcInterceptor(interceptor)
 
-			require.Less(
-				t.t,
-				request.OutgoingExpiry, request.IncomingExpiry,
-			)
-			require.Less(
-				t.t,
-				request.OutgoingAmountMsat,
-				request.IncomingAmountMsat,
-			)
+		// Assert sanity of informational packet data.
+		require.NotZero(ht, request.OutgoingRequestedChanId)
+		require.NotZero(ht, request.IncomingExpiry)
+		require.NotZero(ht, request.IncomingAmountMsat)
 
-			value, ok := request.CustomRecords[customTestKey]
-			require.True(t.t, ok, "expected custom record")
-			require.Equal(t.t, customTestValue, value)
+		require.Less(ht, request.OutgoingExpiry,
+			request.IncomingExpiry)
+		require.Less(ht, request.OutgoingAmountMsat,
+			request.IncomingAmountMsat)
 
-			testCase := testCases[i]
+		value, ok := request.CustomRecords[customTestKey]
+		require.True(ht, ok, "expected custom record")
+		require.Equal(ht, customTestValue, value)
 
-			// For held packets we ignore, keeping them in hold status.
-			if testCase.shouldHold {
-				continue
-			}
-
-			// For all other packets we resolve according to the test case.
-			_ = interceptor.Send(&routerrpc.ForwardHtlcInterceptResponse{
-				IncomingCircuitKey: request.IncomingCircuitKey,
-				Action:             testCase.interceptorAction,
-				Preimage:           testCase.invoice.RPreimage,
-			})
-		case <-time.After(defaultTimeout):
-			t.Fatalf("response from interceptor was not received %v", i)
+		// For held packets we ignore, keeping them in hold status.
+		if tc.shouldHold {
+			continue
 		}
+
+		// For all other packets we resolve according to the test case.
+		err := interceptor.Send(&routerrpc.ForwardHtlcInterceptResponse{
+			IncomingCircuitKey: request.IncomingCircuitKey,
+			Action:             tc.interceptorAction,
+			Preimage:           tc.invoice.RPreimage,
+		})
+		require.NoError(ht, err, "failed to send request")
 	}
 
-	// At this point we are left with the held packets, we want to make sure
-	// each one of them has a corresponding 'in-flight' payment at
+	// At this point we are left with the held packets, we want to make
+	// sure each one of them has a corresponding 'in-flight' payment at
 	// Alice's node.
-	payments, err := testContext.alice.ListPayments(context.Background(),
-		&lnrpc.ListPaymentsRequest{IncludeIncomplete: true})
-	require.NoError(t.t, err, "failed to fetch payment")
-
 	for _, testCase := range testCases {
-		if testCase.shouldHold {
-			hashStr := hex.EncodeToString(testCase.invoice.RHash)
-			var foundPayment *lnrpc.Payment
-			expectedAmt := testCase.invoice.ValueMsat
-			for _, p := range payments.Payments {
-				if p.PaymentHash == hashStr {
-					foundPayment = p
-					break
-				}
-			}
-			require.NotNil(t.t, foundPayment, fmt.Sprintf("expected "+
-				"to find pending payment for held htlc %v",
-				hashStr))
-			require.Equal(t.t, lnrpc.Payment_IN_FLIGHT,
-				foundPayment.Status, "expected payment to be "+
-					"in flight")
-			require.Equal(t.t, expectedAmt, foundPayment.ValueMsat,
-				"incorrect in flight amount")
+		if !testCase.shouldHold {
+			continue
 		}
+
+		var preimage lntypes.Preimage
+		copy(preimage[:], testCase.invoice.RPreimage)
+
+		payment := ht.AssertPaymentStatus(
+			alice, preimage, lnrpc.Payment_IN_FLIGHT,
+		)
+		expectedAmt := testCase.invoice.ValueMsat
+		require.Equal(ht, expectedAmt, payment.ValueMsat,
+			"incorrect in flight amount")
 	}
 
-	// Disconnect interceptor should cause resume held packets.
-	// After that we wait for all go routines to finish, including the one
-	// that tests the payment final status for the held payment.
+	// Cancel the context, which will disconnect the above interceptor.
 	cancelInterceptor()
-	wg.Wait()
+
+	// Disconnect interceptor should cause resume held packets. After that
+	// we wait for all go routines to finish, including the one that tests
+	// the payment final status for the held payment.
+	select {
+	case <-done:
+	case <-time.After(defaultTimeout):
+		require.Fail(ht, "timeout waiting for sending payment")
+	}
 
 	// Verify that we don't get notified about already completed HTLCs
 	// We do that by restarting alice, the sender the HTLCs. Under
 	// https://github.com/lightningnetwork/lnd/issues/5115
-	// this should cause all HTLCs settled or failed by the interceptor to renotify.
-	restartAlice, err := net.SuspendNode(alice)
-	require.NoError(t.t, err, "failed to suspend alice")
+	// this should cause all HTLCs settled or failed by the interceptor to
+	// renotify.
+	restartAlice := ht.SuspendNode(alice)
+	require.NoError(ht, restartAlice(), "failed to restart alice")
 
-	ctxt, cancelInterceptor = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancelInterceptor()
-	interceptor, err = testContext.bob.RouterClient.HtlcInterceptor(ctxt)
-	require.NoError(t.t, err, "failed to create HtlcInterceptor")
+	// Make sure the channel is active from Bob's PoV.
+	ht.AssertChannelExists(bob, cpAB)
 
-	err = restartAlice()
-	require.NoError(t.t, err, "failed to restart alice")
+	// Create a new interceptor as the old one has quit.
+	interceptor, cancelInterceptor = bob.RPC.HtlcInterceptor()
 
+	done = make(chan struct{})
 	go func() {
-		request, err := interceptor.Recv()
-		if err != nil {
-			// If it is  just the error result of the context cancellation
-			// the we exit silently.
-			status, ok := status.FromError(err)
-			if ok && status.Code() == codes.Canceled {
-				return
-			}
-			// Otherwise it an unexpected error, we fail the test.
-			require.NoError(
-				t.t, err, "unexpected error in interceptor.Recv()",
-			)
+		defer close(done)
+
+		_, err := interceptor.Recv()
+		require.Error(ht, err, "expected an error from interceptor")
+
+		status, ok := status.FromError(err)
+		switch {
+		// If it is just the error result of the context cancellation
+		// the we exit silently.
+		case ok && status.Code() == codes.Canceled:
+			fallthrough
+
+		// When the test ends, during the node's shutdown it will close
+		// the connection.
+		case strings.Contains(err.Error(), "closed network connection"):
+			fallthrough
+
+		case strings.Contains(err.Error(), "EOF"):
 			return
 		}
 
-		require.Nil(t.t, request, "no more intercepts should arrive")
+		// Otherwise we receive an unexpected error.
+		require.Failf(ht, "iinterceptor", "unexpected err: %v", err)
 	}()
 
-	err = wait.Predicate(func() bool {
-		channels, err := bob.ListChannels(ctxt, &lnrpc.ListChannelsRequest{
-			ActiveOnly: true, Peer: alice.PubKey[:],
-		})
-		return err == nil && len(channels.Channels) > 0
-	}, defaultTimeout)
-	require.NoError(t.t, err, "alice <> bob channel didn't re-activate")
-}
-
-// interceptorTestContext is a helper struct to hold the test context and
-// provide the needed functionality.
-type interceptorTestContext struct {
-	t   *harnessTest
-	net *lntest.NetworkHarness
-
-	// Keep a list of all our active channels.
-	networkChans      []*lnrpc.ChannelPoint
-	closeChannelFuncs []func()
-
-	alice, bob, carol *lntest.HarnessNode
-	nodes             []*lntest.HarnessNode
-}
-
-func newInterceptorTestContext(t *harnessTest,
-	net *lntest.NetworkHarness,
-	alice, bob, carol *lntest.HarnessNode) *interceptorTestContext {
-
-	// Connect nodes
-	nodes := []*lntest.HarnessNode{alice, bob, carol}
-	for i := 0; i < len(nodes); i++ {
-		for j := i + 1; j < len(nodes); j++ {
-			net.EnsureConnected(t.t, nodes[i], nodes[j])
-		}
+	// Cancel the context, which will disconnect the above interceptor.
+	cancelInterceptor()
+	select {
+	case <-done:
+	case <-time.After(defaultTimeout):
+		require.Fail(ht, "timeout waiting for interceptor error")
 	}
 
-	ctx := interceptorTestContext{
-		t:     t,
-		net:   net,
+	// Finally, close channels.
+	ht.CloseChannel(alice, cpAB)
+	ht.CloseChannel(bob, cpBC)
+}
+
+// interceptorTestScenario is a helper struct to hold the test context and
+// provide the needed functionality.
+type interceptorTestScenario struct {
+	ht                *lntemp.HarnessTest
+	alice, bob, carol *node.HarnessNode
+}
+
+// newInterceptorTestScenario initializes a new test scenario with three nodes
+// and connects them to have the following topology,
+//
+//	Alice --> Bob --> Carol
+//
+// Among them, Alice and Bob are standby nodes and Carol is a new node.
+func newInterceptorTestScenario(
+	ht *lntemp.HarnessTest) *interceptorTestScenario {
+
+	alice, bob := ht.Alice, ht.Bob
+	carol := ht.NewNode("carol", nil)
+
+	ht.EnsureConnected(alice, bob)
+	ht.EnsureConnected(bob, carol)
+
+	return &interceptorTestScenario{
+		ht:    ht,
 		alice: alice,
 		bob:   bob,
 		carol: carol,
-		nodes: nodes,
 	}
-
-	return &ctx
 }
 
 // prepareTestCases prepares 4 tests:
@@ -470,36 +377,41 @@ func newInterceptorTestContext(t *harnessTest,
 // 2. resumed htlc.
 // 3. settling htlc externally.
 // 4. held htlc that is resumed later.
-func (c *interceptorTestContext) prepareTestCases() []*interceptorTestCase {
+func (c *interceptorTestScenario) prepareTestCases() []*interceptorTestCase {
+	var (
+		actionFail   = routerrpc.ResolveHoldForwardAction_FAIL
+		actionResume = routerrpc.ResolveHoldForwardAction_RESUME
+		actionSettle = routerrpc.ResolveHoldForwardAction_SETTLE
+	)
+
 	cases := []*interceptorTestCase{
-		{amountMsat: 1000, shouldHold: false,
-			interceptorAction: routerrpc.ResolveHoldForwardAction_FAIL},
-		{amountMsat: 1000, shouldHold: false,
-			interceptorAction: routerrpc.ResolveHoldForwardAction_RESUME},
-		{amountMsat: 1000, shouldHold: false,
-			interceptorAction: routerrpc.ResolveHoldForwardAction_SETTLE},
-		{amountMsat: 1000, shouldHold: true,
-			interceptorAction: routerrpc.ResolveHoldForwardAction_RESUME},
+		{
+			amountMsat: 1000, shouldHold: false,
+			interceptorAction: actionFail,
+		},
+		{
+			amountMsat: 1000, shouldHold: false,
+			interceptorAction: actionResume,
+		},
+		{
+			amountMsat: 1000, shouldHold: false,
+			interceptorAction: actionSettle,
+		},
+		{
+			amountMsat: 1000, shouldHold: true,
+			interceptorAction: actionResume,
+		},
 	}
 
 	for _, t := range cases {
-		addResponse, err := c.carol.AddInvoice(context.Background(), &lnrpc.Invoice{
-			ValueMsat: t.amountMsat,
-		})
-		require.NoError(c.t.t, err, "unable to add invoice")
-
-		invoice, err := c.carol.LookupInvoice(context.Background(), &lnrpc.PaymentHash{
-			RHashStr: hex.EncodeToString(addResponse.RHash),
-		})
-		require.NoError(c.t.t, err, "unable to find invoice")
+		inv := &lnrpc.Invoice{ValueMsat: t.amountMsat}
+		addResponse := c.carol.RPC.AddInvoice(inv)
+		invoice := c.carol.RPC.LookupInvoice(addResponse.RHash)
 
 		// We'll need to also decode the returned invoice so we can
 		// grab the payment address which is now required for ALL
 		// payments.
-		payReq, err := c.carol.DecodePayReq(context.Background(), &lnrpc.PayReqString{
-			PayReq: invoice.PaymentRequest,
-		})
-		require.NoError(c.t.t, err, "unable to decode invoice")
+		payReq := c.carol.RPC.DecodePayReq(invoice.PaymentRequest)
 
 		t.invoice = invoice
 		t.payAddr = payReq.PaymentAddr
@@ -507,69 +419,15 @@ func (c *interceptorTestContext) prepareTestCases() []*interceptorTestCase {
 	return cases
 }
 
-func (c *interceptorTestContext) openChannel(from, to *lntest.HarnessNode,
-	chanSize btcutil.Amount) {
-
-	c.net.SendCoins(c.t.t, btcutil.SatoshiPerBitcoin, from)
-
-	chanPoint := openChannelAndAssert(
-		c.t, c.net, from, to,
-		lntest.OpenChannelParams{
-			Amt: chanSize,
-		},
-	)
-
-	c.closeChannelFuncs = append(c.closeChannelFuncs, func() {
-		closeChannelAndAssert(c.t, c.net, from, chanPoint, false)
-	})
-
-	c.networkChans = append(c.networkChans, chanPoint)
-}
-
-func (c *interceptorTestContext) closeChannels() {
-	for _, f := range c.closeChannelFuncs {
-		f()
-	}
-}
-
-func (c *interceptorTestContext) waitForChannels() {
-	// Wait for all nodes to have seen all channels.
-	for _, chanPoint := range c.networkChans {
-		for _, node := range c.nodes {
-			txid, err := lnrpc.GetChanPointFundingTxid(chanPoint)
-			require.NoError(c.t.t, err, "unable to get txid")
-
-			point := wire.OutPoint{
-				Hash:  *txid,
-				Index: chanPoint.OutputIndex,
-			}
-
-			err = node.WaitForNetworkChannelOpen(chanPoint)
-			require.NoError(c.t.t, err, fmt.Sprintf("(%d): timeout "+
-				"waiting for channel(%s) open", node.NodeID,
-				point))
-		}
-	}
-}
-
-// sendAliceToCarolPayment sends a payment from alice to carol and make an
-// attempt to pay. The lnrpc.HTLCAttempt is returned.
-func (c *interceptorTestContext) sendAliceToCarolPayment(ctx context.Context,
-	amtMsat int64,
-	paymentHash, paymentAddr []byte) (*lnrpc.HTLCAttempt, error) {
+// sendPaymentAndAssertAction sends a payment from alice to carol and asserts
+// that the specified interceptor action is taken.
+func (c *interceptorTestScenario) sendPaymentAndAssertAction(
+	tc *interceptorTestCase) *lnrpc.HTLCAttempt {
 
 	// Build a route from alice to carol.
-	route, err := c.buildRoute(
-		ctx, amtMsat, []*lntest.HarnessNode{c.bob, c.carol},
-		paymentAddr,
+	route := c.buildRoute(
+		tc.amountMsat, []*node.HarnessNode{c.bob, c.carol}, tc.payAddr,
 	)
-	if err != nil {
-		return nil, err
-	}
-	sendReq := &routerrpc.SendToRouteRequest{
-		PaymentHash: paymentHash,
-		Route:       route,
-	}
 
 	// Send a custom record to the forwarding node.
 	route.Hops[0].CustomRecords = map[uint64][]byte{
@@ -577,21 +435,51 @@ func (c *interceptorTestContext) sendAliceToCarolPayment(ctx context.Context,
 	}
 
 	// Send the payment.
-	return c.alice.RouterClient.SendToRouteV2(ctx, sendReq)
+	sendReq := &routerrpc.SendToRouteRequest{
+		PaymentHash: tc.invoice.RHash,
+		Route:       route,
+	}
+
+	return c.alice.RPC.SendToRouteV2(sendReq)
+}
+
+func (c *interceptorTestScenario) assertAction(tc *interceptorTestCase,
+	attempt *lnrpc.HTLCAttempt) {
+
+	// Now check the expected action has been taken.
+	switch tc.interceptorAction {
+	// For 'fail' interceptor action we make sure the payment failed.
+	case routerrpc.ResolveHoldForwardAction_FAIL:
+		require.Equal(c.ht, lnrpc.HTLCAttempt_FAILED, attempt.Status,
+			"expected payment to fail")
+
+		// Assert that we get a temporary channel failure which has a
+		// channel update.
+		require.NotNil(c.ht, attempt.Failure)
+		require.NotNil(c.ht, attempt.Failure.ChannelUpdate)
+
+		require.Equal(c.ht, lnrpc.Failure_TEMPORARY_CHANNEL_FAILURE,
+			attempt.Failure.Code)
+
+	// For settle and resume we make sure the payment is successful.
+	case routerrpc.ResolveHoldForwardAction_SETTLE:
+		fallthrough
+
+	case routerrpc.ResolveHoldForwardAction_RESUME:
+		require.Equal(c.ht, lnrpc.HTLCAttempt_SUCCEEDED,
+			attempt.Status, "expected payment to succeed")
+	}
 }
 
 // buildRoute is a helper function to build a route with given hops.
-func (c *interceptorTestContext) buildRoute(ctx context.Context, amtMsat int64,
-	hops []*lntest.HarnessNode, payAddr []byte) (*lnrpc.Route, error) {
+func (c *interceptorTestScenario) buildRoute(amtMsat int64,
+	hops []*node.HarnessNode, payAddr []byte) *lnrpc.Route {
 
 	rpcHops := make([][]byte, 0, len(hops))
 	for _, hop := range hops {
 		k := hop.PubKeyStr
 		pubkey, err := route.NewVertexFromStr(k)
-		if err != nil {
-			return nil, fmt.Errorf("error parsing %v: %v",
-				k, err)
-		}
+		require.NoErrorf(c.ht, err, "error parsing %v: %v", k, err)
 		rpcHops = append(rpcHops, pubkey[:])
 	}
 
@@ -602,10 +490,7 @@ func (c *interceptorTestContext) buildRoute(ctx context.Context, amtMsat int64,
 		PaymentAddr:    payAddr,
 	}
 
-	routeResp, err := c.alice.RouterClient.BuildRoute(ctx, req)
-	if err != nil {
-		return nil, err
-	}
+	routeResp := c.alice.RPC.BuildRoute(req)
 
-	return routeResp.Route, nil
+	return routeResp.Route
 }

lntest/itest/lnd_mpp_test.go

@@ -1,27 +1,23 @@
 package itest
 
 import (
-	"bytes"
-	"context"
-	"fmt"
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil"
-	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainreg"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
+	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/routing/route"
+	"github.com/stretchr/testify/require"
 )
 
 // testSendToRouteMultiPath tests that we are able to successfully route a
 // payment using multiple shards across different paths, by using SendToRoute.
-func testSendToRouteMultiPath(net *lntest.NetworkHarness, t *harnessTest) {
-	ctxb := context.Background()
-
-	ctx := newMppTestContext(t, net)
-	defer ctx.shutdownNodes()
+func testSendToRouteMultiPath(ht *lntemp.HarnessTest) {
+	mts := newMppTestScenario(ht)
 
 	// To ensure the payment goes through separate paths, we'll set a
 	// channel size that can only carry one shard at a time. We'll divide
@@ -39,55 +35,41 @@ func testSendToRouteMultiPath(net *lntest.NetworkHarness, t *harnessTest) {
 	//      \              /
 	//       \__ Dave ____/
 	//
-	ctx.openChannel(ctx.carol, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.dave, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.alice, ctx.dave, chanAmt)
-	ctx.openChannel(ctx.eve, ctx.bob, chanAmt)
-	ctx.openChannel(ctx.carol, ctx.eve, chanAmt)
-
-	// Since the channel Alice-> Carol will have to carry two
-	// shards, we make it larger.
-	ctx.openChannel(ctx.alice, ctx.carol, chanAmt+shardAmt)
-
-	defer ctx.closeChannels()
-
-	ctx.waitForChannels()
+	req := &mppOpenChannelRequest{
+		// Since the channel Alice-> Carol will have to carry two
+		// shards, we make it larger.
+		amtAliceCarol: chanAmt + shardAmt,
+		amtAliceDave:  chanAmt,
+		amtCarolBob:   chanAmt,
+		amtCarolEve:   chanAmt,
+		amtDaveBob:    chanAmt,
+		amtEveBob:     chanAmt,
+	}
+	mts.openChannels(req)
 
 	// Make Bob create an invoice for Alice to pay.
-	payReqs, rHashes, invoices, err := createPayReqs(
-		ctx.bob, paymentAmt, 1,
-	)
-	if err != nil {
-		t.Fatalf("unable to create pay reqs: %v", err)
-	}
+	payReqs, rHashes, invoices := ht.CreatePayReqs(mts.bob, paymentAmt, 1)
 
 	rHash := rHashes[0]
 	payReq := payReqs[0]
 
-	ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-	decodeResp, err := ctx.bob.DecodePayReq(
-		ctxt, &lnrpc.PayReqString{PayReq: payReq},
-	)
-	if err != nil {
-		t.Fatalf("decode pay req: %v", err)
-	}
-
+	decodeResp := mts.bob.RPC.DecodePayReq(payReq)
 	payAddr := decodeResp.PaymentAddr
 
+	// Subscribe the invoice.
+	stream := mts.bob.RPC.SubscribeSingleInvoice(rHash)
+
 	// We'll send shards along three routes from Alice.
-	sendRoutes := [][]*lntest.HarnessNode{
-		{ctx.carol, ctx.bob},
-		{ctx.dave, ctx.bob},
-		{ctx.carol, ctx.eve, ctx.bob},
+	sendRoutes := [][]*node.HarnessNode{
+		{mts.carol, mts.bob},
+		{mts.dave, mts.bob},
+		{mts.carol, mts.eve, mts.bob},
 	}
 
 	responses := make(chan *lnrpc.HTLCAttempt, len(sendRoutes))
 	for _, hops := range sendRoutes {
 		// Build a route for the specified hops.
-		r, err := ctx.buildRoute(ctxb, shardAmt, ctx.alice, hops)
-		if err != nil {
-			t.Fatalf("unable to build route: %v", err)
-		}
+		r := mts.buildRoute(shardAmt, mts.alice, hops)
 
 		// Set the MPP records to indicate this is a payment shard.
 		hop := r.Hops[len(r.Hops)-1]
@@ -103,62 +85,44 @@ func testSendToRouteMultiPath(net *lntest.NetworkHarness, t *harnessTest) {
 			Route:       r,
 		}
 
-		// We'll send all shards in their own goroutine, since SendToRoute will
-		// block as long as the payment is in flight.
+		// We'll send all shards in their own goroutine, since
+		// SendToRoute will block as long as the payment is in flight.
 		go func() {
-			ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-			resp, err := ctx.alice.RouterClient.SendToRouteV2(ctxt, sendReq)
-			if err != nil {
-				t.Fatalf("unable to send payment: %v", err)
-			}
-
+			resp := mts.alice.RPC.SendToRouteV2(sendReq)
 			responses <- resp
 		}()
 	}
 
 	// Wait for all responses to be back, and check that they all
 	// succeeded.
+	timer := time.After(defaultTimeout)
 	for range sendRoutes {
 		var resp *lnrpc.HTLCAttempt
 		select {
 		case resp = <-responses:
-		case <-time.After(defaultTimeout):
-			t.Fatalf("response not received")
+		case <-timer:
+			require.Fail(ht, "response not received")
 		}
 
-		if resp.Failure != nil {
-			t.Fatalf("received payment failure : %v", resp.Failure)
-		}
+		require.Nil(ht, resp.Failure, "received payment failure")
 
 		// All shards should come back with the preimage.
-		if !bytes.Equal(resp.Preimage, invoices[0].RPreimage) {
-			t.Fatalf("preimage doesn't match")
-		}
+		require.Equal(ht, resp.Preimage, invoices[0].RPreimage,
+			"preimage doesn't match")
 	}
 
 	// assertNumHtlcs is a helper that checks the node's latest payment,
 	// and asserts it was split into num shards.
-	assertNumHtlcs := func(node *lntest.HarnessNode, num int) {
-		req := &lnrpc.ListPaymentsRequest{
-			IncludeIncomplete: true,
-		}
-		ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-		paymentsResp, err := node.ListPayments(ctxt, req)
-		if err != nil {
-			t.Fatalf("error when obtaining payments: %v",
-				err)
-		}
+	assertNumHtlcs := func(hn *node.HarnessNode, num int) {
+		var preimage lntypes.Preimage
+		copy(preimage[:], invoices[0].RPreimage)
 
-		payments := paymentsResp.Payments
-		if len(payments) == 0 {
-			t.Fatalf("no payments found")
-		}
+		payment := ht.AssertPaymentStatus(
+			hn, preimage, lnrpc.Payment_SUCCEEDED,
+		)
 
-		payment := payments[len(payments)-1]
 		htlcs := payment.Htlcs
-		if len(htlcs) == 0 {
-			t.Fatalf("no htlcs")
-		}
+		require.NotEmpty(ht, htlcs, "no htlcs")
 
 		succeeded := 0
 		for _, htlc := range htlcs {
@@ -166,194 +130,217 @@ func testSendToRouteMultiPath(net *lntest.NetworkHarness, t *harnessTest) {
 				succeeded++
 			}
 		}
-
-		if succeeded != num {
-			t.Fatalf("expected %v succussful HTLCs, got %v", num,
-				succeeded)
-		}
+		require.Equal(ht, num, succeeded, "HTLCs not matched")
 	}
 
 	// assertSettledInvoice checks that the invoice for the given payment
 	// hash is settled, and has been paid using num HTLCs.
-	assertSettledInvoice := func(node *lntest.HarnessNode, rhash []byte,
-		num int) {
+	assertSettledInvoice := func(rhash []byte, num int) {
+		var payHash lntypes.Hash
+		copy(payHash[:], rhash)
+		inv := ht.AssertInvoiceState(stream, lnrpc.Invoice_SETTLED)
 
-		found := false
-		offset := uint64(0)
-		for !found {
-			ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-			invoicesResp, err := node.ListInvoices(
-				ctxt, &lnrpc.ListInvoiceRequest{
-					IndexOffset: offset,
-				},
-			)
-			if err != nil {
-				t.Fatalf("error when obtaining payments: %v",
-					err)
-			}
+		// Assert that the amount paid to the invoice is correct.
+		require.EqualValues(ht, paymentAmt, inv.AmtPaidSat,
+			"incorrect payment amt")
 
-			if len(invoicesResp.Invoices) == 0 {
-				break
-			}
-
-			for _, inv := range invoicesResp.Invoices {
-				if !bytes.Equal(inv.RHash, rhash) {
-					continue
-				}
-
-				// Assert that the amount paid to the invoice is
-				// correct.
-				if inv.AmtPaidSat != int64(paymentAmt) {
-					t.Fatalf("incorrect payment amt for "+
-						"invoicewant: %d, got %d",
-						paymentAmt, inv.AmtPaidSat)
-				}
-
-				if inv.State != lnrpc.Invoice_SETTLED {
-					t.Fatalf("Invoice not settled: %v",
-						inv.State)
-				}
-
-				if len(inv.Htlcs) != num {
-					t.Fatalf("expected invoice to be "+
-						"settled with %v HTLCs, had %v",
-						num, len(inv.Htlcs))
-				}
-
-				found = true
-				break
-			}
-
-			offset = invoicesResp.LastIndexOffset
-		}
-
-		if !found {
-			t.Fatalf("invoice not found")
-		}
+		require.Len(ht, inv.Htlcs, num, "wrong num of HTLCs")
 	}
 
 	// Finally check that the payment shows up with three settled HTLCs in
 	// Alice's list of payments...
-	assertNumHtlcs(ctx.alice, 3)
+	assertNumHtlcs(mts.alice, 3)
 
 	// ...and in Bob's list of paid invoices.
-	assertSettledInvoice(ctx.bob, rHash, 3)
+	assertSettledInvoice(rHash, 3)
+
+	// Finally, close all channels.
+	mts.closeChannels()
 }
 
-type mppTestContext struct {
-	t   *harnessTest
-	net *lntest.NetworkHarness
+// mppTestScenario defines a test scenario used for testing MPP-related tests.
+// It has two standby nodes, alice and bob, and three new nodes, carol, dave,
+// and eve.
+type mppTestScenario struct {
+	ht *lntemp.HarnessTest
+
+	alice, bob, carol, dave, eve *node.HarnessNode
+	nodes                        []*node.HarnessNode
 
 	// Keep a list of all our active channels.
-	networkChans      []*lnrpc.ChannelPoint
-	closeChannelFuncs []func()
-
-	alice, bob, carol, dave, eve *lntest.HarnessNode
-	nodes                        []*lntest.HarnessNode
+	channelPoints []*lnrpc.ChannelPoint
 }
 
-func newMppTestContext(t *harnessTest,
-	net *lntest.NetworkHarness) *mppTestContext {
-
-	alice := net.NewNode(t.t, "alice", nil)
-	bob := net.NewNode(t.t, "bob", []string{"--accept-amp"})
+// newMppTestScenario initializes a new mpp test scenario with five funded
+// nodes and connects them to have the following topology,
+//
+//	            _ Eve _
+//	           /       \
+//	Alice -- Carol ---- Bob
+//	    \              /
+//	     \__ Dave ____/
+func newMppTestScenario(ht *lntemp.HarnessTest) *mppTestScenario {
+	alice, bob := ht.Alice, ht.Bob
+	ht.RestartNodeWithExtraArgs(bob, []string{
+		"--maxpendingchannels=2",
+		"--accept-amp",
+	})
 
 	// Create a five-node context consisting of Alice, Bob and three new
 	// nodes.
-	carol := net.NewNode(t.t, "carol", nil)
-	dave := net.NewNode(t.t, "dave", nil)
-	eve := net.NewNode(t.t, "eve", nil)
+	carol := ht.NewNode("carol", []string{
+		"--maxpendingchannels=2",
+		"--accept-amp",
+	})
+	dave := ht.NewNode("dave", nil)
+	eve := ht.NewNode("eve", nil)
 
 	// Connect nodes to ensure propagation of channels.
-	nodes := []*lntest.HarnessNode{alice, bob, carol, dave, eve}
-	for i := 0; i < len(nodes); i++ {
-		for j := i + 1; j < len(nodes); j++ {
-			net.EnsureConnected(t.t, nodes[i], nodes[j])
-		}
+	ht.EnsureConnected(alice, carol)
+	ht.EnsureConnected(alice, dave)
+	ht.EnsureConnected(carol, bob)
+	ht.EnsureConnected(carol, eve)
+	ht.EnsureConnected(dave, bob)
+	ht.EnsureConnected(eve, bob)
+
+	// Send coins to the nodes and mine 1 blocks to confirm them.
+	for i := 0; i < 2; i++ {
+		ht.FundCoinsUnconfirmed(btcutil.SatoshiPerBitcoin, carol)
+		ht.FundCoinsUnconfirmed(btcutil.SatoshiPerBitcoin, dave)
+		ht.FundCoinsUnconfirmed(btcutil.SatoshiPerBitcoin, eve)
+		ht.MineBlocks(1)
 	}
 
-	ctx := mppTestContext{
-		t:     t,
-		net:   net,
+	mts := &mppTestScenario{
+		ht:    ht,
 		alice: alice,
 		bob:   bob,
 		carol: carol,
 		dave:  dave,
 		eve:   eve,
-		nodes: nodes,
+		nodes: []*node.HarnessNode{alice, bob, carol, dave, eve},
 	}
 
-	return &ctx
+	return mts
 }
 
-// openChannel is a helper to open a channel from->to.
-func (c *mppTestContext) openChannel(from, to *lntest.HarnessNode,
-	chanSize btcutil.Amount) {
+// mppOpenChannelRequest defines the amounts used for each channel opening.
+type mppOpenChannelRequest struct {
+	// Channel Alice=>Carol.
+	amtAliceCarol btcutil.Amount
 
-	c.net.SendCoins(c.t.t, btcutil.SatoshiPerBitcoin, from)
+	// Channel Alice=>Dave.
+	amtAliceDave btcutil.Amount
 
-	chanPoint := openChannelAndAssert(
-		c.t, c.net, from, to,
-		lntest.OpenChannelParams{Amt: chanSize},
-	)
+	// Channel Carol=>Bob.
+	amtCarolBob btcutil.Amount
 
-	c.closeChannelFuncs = append(c.closeChannelFuncs, func() {
-		closeChannelAndAssert(c.t, c.net, from, chanPoint, false)
-	})
+	// Channel Carol=>Eve.
+	amtCarolEve btcutil.Amount
 
-	c.networkChans = append(c.networkChans, chanPoint)
+	// Channel Dave=>Bob.
+	amtDaveBob btcutil.Amount
+
+	// Channel Eve=>Bob.
+	amtEveBob btcutil.Amount
 }
 
-func (c *mppTestContext) closeChannels() {
-	for _, f := range c.closeChannelFuncs {
-		f()
+// openChannels is a helper to open channels that sets up a network topology
+// with three different paths Alice <-> Bob as following,
+//
+//		 _ Eve _
+//		/       \
+//	 Alice -- Carol ---- Bob
+//		\              /
+//		 \__ Dave ____/
+//
+// NOTE: all the channels are open together to save blocks mined.
+func (m *mppTestScenario) openChannels(r *mppOpenChannelRequest) {
+	reqs := []*lntemp.OpenChannelRequest{
+		{
+			Local:  m.alice,
+			Remote: m.carol,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtAliceCarol},
+		},
+		{
+			Local:  m.alice,
+			Remote: m.dave,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtAliceDave},
+		},
+		{
+			Local:  m.carol,
+			Remote: m.bob,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtCarolBob},
+		},
+		{
+			Local:  m.carol,
+			Remote: m.eve,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtCarolEve},
+		},
+		{
+			Local:  m.dave,
+			Remote: m.bob,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtDaveBob},
+		},
+		{
+			Local:  m.eve,
+			Remote: m.bob,
+			Param:  lntemp.OpenChannelParams{Amt: r.amtEveBob},
+		},
 	}
-}
 
-func (c *mppTestContext) shutdownNodes() {
-	shutdownAndAssert(c.net, c.t, c.alice)
-	shutdownAndAssert(c.net, c.t, c.bob)
-	shutdownAndAssert(c.net, c.t, c.carol)
-	shutdownAndAssert(c.net, c.t, c.dave)
-	shutdownAndAssert(c.net, c.t, c.eve)
-}
+	m.channelPoints = m.ht.OpenMultiChannelsAsync(reqs)
 
-func (c *mppTestContext) waitForChannels() {
-	// Wait for all nodes to have seen all channels.
-	for _, chanPoint := range c.networkChans {
-		for _, node := range c.nodes {
-			txid, err := lnrpc.GetChanPointFundingTxid(chanPoint)
-			if err != nil {
-				c.t.Fatalf("unable to get txid: %v", err)
-			}
-			point := wire.OutPoint{
-				Hash:  *txid,
-				Index: chanPoint.OutputIndex,
-			}
-
-			err = node.WaitForNetworkChannelOpen(chanPoint)
-			if err != nil {
-				c.t.Fatalf("(%v:%d): timeout waiting for "+
-					"channel(%s) open: %v",
-					node.Cfg.Name, node.NodeID, point, err)
-			}
+	// Make sure every node has heard every channel.
+	for _, hn := range m.nodes {
+		for _, cp := range m.channelPoints {
+			m.ht.AssertTopologyChannelOpen(hn, cp)
 		}
 	}
 }
 
+// closeChannels closes all the open channels from `openChannels`.
+func (m *mppTestScenario) closeChannels() {
+	if m.ht.Failed() {
+		m.ht.Log("Skipped closing channels for failed test")
+		return
+	}
+
+	// TODO(yy): remove the sleep once the following bug is fixed. When the
+	// payment is reported as settled by Alice, it's expected the
+	// commitment dance is finished and all subsequent states have been
+	// updated. Yet we'd receive the error `cannot co-op close channel with
+	// active htlcs` or `link failed to shutdown` if we close the channel.
+	// We need to investigate the order of settling the payments and
+	// updating commitments to understand and fix .
+	time.Sleep(2 * time.Second)
+
+	// Close all channels without mining the closing transactions.
+	m.ht.CloseChannelAssertPending(m.alice, m.channelPoints[0], false)
+	m.ht.CloseChannelAssertPending(m.alice, m.channelPoints[1], false)
+	m.ht.CloseChannelAssertPending(m.carol, m.channelPoints[2], false)
+	m.ht.CloseChannelAssertPending(m.carol, m.channelPoints[3], false)
+	m.ht.CloseChannelAssertPending(m.dave, m.channelPoints[4], false)
+	m.ht.CloseChannelAssertPending(m.eve, m.channelPoints[5], false)
+
+	// Now mine a block to include all the closing transactions.
+	m.ht.MineBlocks(1)
+
+	// Assert that the channels are closed.
+	for _, hn := range m.nodes {
+		m.ht.AssertNumWaitingClose(hn, 0)
+	}
+}
+
 // Helper function for Alice to build a route from pubkeys.
-func (c *mppTestContext) buildRoute(ctxb context.Context, amt btcutil.Amount,
-	sender *lntest.HarnessNode, hops []*lntest.HarnessNode) (*lnrpc.Route,
-	error) {
+func (m *mppTestScenario) buildRoute(amt btcutil.Amount,
+	sender *node.HarnessNode, hops []*node.HarnessNode) *lnrpc.Route {
 
 	rpcHops := make([][]byte, 0, len(hops))
 	for _, hop := range hops {
 		k := hop.PubKeyStr
 		pubkey, err := route.NewVertexFromStr(k)
-		if err != nil {
-			return nil, fmt.Errorf("error parsing %v: %v",
-				k, err)
-		}
+		require.NoErrorf(m.ht, err, "error parsing %v: %v", k, err)
 		rpcHops = append(rpcHops, pubkey[:])
 	}
 
@@ -362,12 +349,37 @@ func (c *mppTestContext) buildRoute(ctxb context.Context, amt btcutil.Amount,
 		FinalCltvDelta: chainreg.DefaultBitcoinTimeLockDelta,
 		HopPubkeys:     rpcHops,
 	}
+	routeResp := sender.RPC.BuildRoute(req)
 
-	ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-	routeResp, err := sender.RouterClient.BuildRoute(ctxt, req)
-	if err != nil {
-		return nil, err
+	return routeResp.Route
+}
+
+// updatePolicy updates a Dave's global channel policy and returns the expected
+// policy for further check. It changes Dave's `FeeBaseMsat` from 1000 msat to
+// 500,000 msat, and `FeeProportionalMillonths` from 1 msat to 1000 msat.
+func (m *mppTestScenario) updateDaveGlobalPolicy() *lnrpc.RoutingPolicy {
+	const (
+		baseFeeMsat = 500_000
+		feeRate     = 0.001
+		maxHtlcMsat = 133_650_000
+	)
+
+	expectedPolicy := &lnrpc.RoutingPolicy{
+		FeeBaseMsat:      baseFeeMsat,
+		FeeRateMilliMsat: feeRate * testFeeBase,
+		TimeLockDelta:    40,
+		MinHtlc:          1000, // default value
+		MaxHtlcMsat:      maxHtlcMsat,
 	}
 
-	return routeResp.Route, nil
+	updateFeeReq := &lnrpc.PolicyUpdateRequest{
+		BaseFeeMsat:   baseFeeMsat,
+		FeeRate:       feeRate,
+		TimeLockDelta: 40,
+		Scope:         &lnrpc.PolicyUpdateRequest_Global{Global: true},
+		MaxHtlcMsat:   maxHtlcMsat,
+	}
+	m.dave.RPC.UpdateChannelPolicy(updateFeeReq)
+
+	return expectedPolicy
 }

lntest/itest/lnd_nonstd_sweep_test.go

@@ -1,40 +1,39 @@
 package itest
 
 import (
-	"context"
 	"testing"
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightningnetwork/lnd/lnrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
 	"github.com/stretchr/testify/require"
 )
 
-func testNonstdSweep(net *lntest.NetworkHarness, t *harnessTest) {
+func testNonstdSweep(ht *lntemp.HarnessTest) {
 	p2shAddr, err := btcutil.NewAddressScriptHash(
 		make([]byte, 1), harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	p2pkhAddr, err := btcutil.NewAddressPubKeyHash(
 		make([]byte, 20), harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	p2wshAddr, err := btcutil.NewAddressWitnessScriptHash(
 		make([]byte, 32), harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	p2wkhAddr, err := btcutil.NewAddressWitnessPubKeyHash(
 		make([]byte, 20), harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	p2trAddr, err := btcutil.NewAddressTaproot(
 		make([]byte, 32), harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	tests := []struct {
 		name    string
@@ -64,10 +63,10 @@ func testNonstdSweep(net *lntest.NetworkHarness, t *harnessTest) {
 
 	for _, test := range tests {
 		test := test
-		success := t.t.Run(test.name, func(t *testing.T) {
-			h := newHarnessTest(t, net)
+		success := ht.Run(test.name, func(t *testing.T) {
+			st := ht.Subtest(t)
 
-			testNonStdSweepInner(net, h, test.address)
+			testNonStdSweepInner(st, test.address)
 		})
 		if !success {
 			break
@@ -75,18 +74,14 @@ func testNonstdSweep(net *lntest.NetworkHarness, t *harnessTest) {
 	}
 }
 
-func testNonStdSweepInner(net *lntest.NetworkHarness, t *harnessTest,
-	address string) {
-
-	ctxb := context.Background()
-
-	carol := net.NewNode(t.t, "carol", nil)
+func testNonStdSweepInner(ht *lntemp.HarnessTest, address string) {
+	carol := ht.NewNode("carol", nil)
 
 	// Give Carol a UTXO so SendCoins will behave as expected.
-	net.SendCoins(t.t, btcutil.SatoshiPerBitcoin, carol)
+	ht.FundCoins(btcutil.SatoshiPerBitcoin, carol)
 
 	// Set the fee estimate to 1sat/vbyte.
-	net.SetFeeEstimate(250)
+	ht.SetFeeEstimate(250)
 
 	// Make Carol call SendCoins with the SendAll flag and the created
 	// address.
@@ -96,20 +91,13 @@ func testNonStdSweepInner(net *lntest.NetworkHarness, t *harnessTest,
 		SendAll:     true,
 	}
 
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-
 	// If a non-standard transaction was created, then this SendCoins call
 	// will fail.
-	_, err := carol.SendCoins(ctxt, sendReq)
-	require.NoError(t.t, err)
+	carol.RPC.SendCoins(sendReq)
 
 	// Fetch the txid so we can grab the raw transaction.
-	txid, err := waitForTxInMempool(net.Miner.Client, minerMempoolTimeout)
-	require.NoError(t.t, err)
-
-	tx, err := net.Miner.Client.GetRawTransaction(txid)
-	require.NoError(t.t, err)
+	txid := ht.Miner.AssertNumTxsInMempool(1)[0]
+	tx := ht.Miner.GetRawTransaction(txid)
 
 	msgTx := tx.MsgTx()
 
@@ -123,9 +111,7 @@ func testNonStdSweepInner(net *lntest.NetworkHarness, t *harnessTest,
 	for _, inp := range msgTx.TxIn {
 		// Fetch the previous outpoint's value.
 		prevOut := inp.PreviousOutPoint
-
-		ptx, err := net.Miner.Client.GetRawTransaction(&prevOut.Hash)
-		require.NoError(t.t, err)
+		ptx := ht.Miner.GetRawTransaction(&prevOut.Hash)
 
 		pout := ptx.MsgTx().TxOut[prevOut.Index]
 		inputVal += int(pout.Value)
@@ -139,9 +125,11 @@ func testNonStdSweepInner(net *lntest.NetworkHarness, t *harnessTest,
 
 	// Fetch the vsize of the transaction so we can determine if the
 	// transaction pays >= 1 sat/vbyte.
-	rawTx, err := net.Miner.Client.GetRawTransactionVerbose(txid)
-	require.NoError(t.t, err)
+	rawTx := ht.Miner.GetRawTransactionVerbose(txid)
 
 	// Require fee >= vbytes.
-	require.True(t.t, fee >= int(rawTx.Vsize))
+	require.True(ht, fee >= int(rawTx.Vsize))
+
+	// Mine a block to keep the mempool clean.
+	ht.MineBlocksAndAssertNumTxes(1, 1)
 }

lntest/itest/lnd_onchain_test.go

@@ -2,7 +2,6 @@ package itest
 
 import (
 	"bytes"
-	"context"
 	"fmt"
 
 	"github.com/btcsuite/btcd/btcutil"
@@ -14,7 +13,6 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
 	"github.com/lightningnetwork/lnd/lntemp"
 	"github.com/lightningnetwork/lnd/lntemp/node"
-	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/sweep"
@@ -80,35 +78,28 @@ func testChainKitGetBlockHash(ht *lntemp.HarnessTest) {
 // rate by broadcasting a Child-Pays-For-Parent (CPFP) transaction.
 //
 // TODO(wilmer): Add RBF case once btcd supports it.
-func testCPFP(net *lntest.NetworkHarness, t *harnessTest) {
-	runCPFP(net, t, net.Alice, net.Bob)
+func testCPFP(ht *lntemp.HarnessTest) {
+	runCPFP(ht, ht.Alice, ht.Bob)
 }
 
 // runCPFP ensures that the daemon can bump an unconfirmed  transaction's fee
 // rate by broadcasting a Child-Pays-For-Parent (CPFP) transaction.
-func runCPFP(net *lntest.NetworkHarness, t *harnessTest,
-	alice, bob *lntest.HarnessNode) {
-
+func runCPFP(ht *lntemp.HarnessTest, alice, bob *node.HarnessNode) {
 	// Skip this test for neutrino, as it's not aware of mempool
 	// transactions.
-	if net.BackendCfg.Name() == lntest.NeutrinoBackendName {
-		t.Skipf("skipping CPFP test for neutrino backend")
+	if ht.IsNeutrinoBackend() {
+		ht.Skipf("skipping CPFP test for neutrino backend")
 	}
 
-	// We'll start the test by sending Alice some coins, which she'll use to
-	// send to Bob.
-	ctxb := context.Background()
-	net.SendCoins(t.t, btcutil.SatoshiPerBitcoin, alice)
+	// We'll start the test by sending Alice some coins, which she'll use
+	// to send to Bob.
+	ht.FundCoins(btcutil.SatoshiPerBitcoin, alice)
 
 	// Create an address for Bob to send the coins to.
-	addrReq := &lnrpc.NewAddressRequest{
+	req := &lnrpc.NewAddressRequest{
 		Type: lnrpc.AddressType_WITNESS_PUBKEY_HASH,
 	}
-	ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-	resp, err := bob.NewAddress(ctxt, addrReq)
-	if err != nil {
-		t.Fatalf("unable to get new address for bob: %v", err)
-	}
+	resp := bob.RPC.NewAddress(req)
 
 	// Send the coins from Alice to Bob. We should expect a transaction to
 	// be broadcast and seen in the mempool.
@@ -116,46 +107,33 @@ func runCPFP(net *lntest.NetworkHarness, t *harnessTest,
 		Addr:   resp.Address,
 		Amount: btcutil.SatoshiPerBitcoin,
 	}
-	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
-	if _, err = alice.SendCoins(ctxt, sendReq); err != nil {
-		t.Fatalf("unable to send coins to bob: %v", err)
-	}
-
-	txid, err := waitForTxInMempool(net.Miner.Client, minerMempoolTimeout)
-	if err != nil {
-		t.Fatalf("expected one mempool transaction: %v", err)
-	}
+	alice.RPC.SendCoins(sendReq)
+	txid := ht.Miner.AssertNumTxsInMempool(1)[0]
 
 	// We'll then extract the raw transaction from the mempool in order to
 	// determine the index of Bob's output.
-	tx, err := net.Miner.Client.GetRawTransaction(txid)
-	if err != nil {
-		t.Fatalf("unable to extract raw transaction from mempool: %v",
-			err)
-	}
+	tx := ht.Miner.GetRawTransaction(txid)
 	bobOutputIdx := -1
 	for i, txOut := range tx.MsgTx().TxOut {
 		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
-			txOut.PkScript, net.Miner.ActiveNet,
+			txOut.PkScript, ht.Miner.ActiveNet,
 		)
-		if err != nil {
-			t.Fatalf("unable to extract address from pkScript=%x: "+
-				"%v", txOut.PkScript, err)
-		}
+		require.NoErrorf(ht, err, "unable to extract address "+
+			"from pkScript=%x: %v", txOut.PkScript, err)
+
 		if addrs[0].String() == resp.Address {
 			bobOutputIdx = i
 		}
 	}
-	if bobOutputIdx == -1 {
-		t.Fatalf("bob's output was not found within the transaction")
-	}
+	require.NotEqual(ht, -1, bobOutputIdx, "bob's output was not found "+
+		"within the transaction")
 
 	// Wait until bob has seen the tx and considers it as owned.
 	op := &lnrpc.OutPoint{
 		TxidBytes:   txid[:],
 		OutputIndex: uint32(bobOutputIdx),
 	}
-	assertWalletUnspent(t, bob, op, "")
+	ht.AssertUTXOInWallet(bob, op, "")
 
 	// We'll attempt to bump the fee of this transaction by performing a
 	// CPFP from Alice's point of view.
@@ -165,68 +143,38 @@ func runCPFP(net *lntest.NetworkHarness, t *harnessTest,
 			sweep.DefaultMaxFeeRate.FeePerKVByte() / 2000,
 		),
 	}
-	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
-	_, err = bob.WalletKitClient.BumpFee(ctxt, bumpFeeReq)
-	if err != nil {
-		t.Fatalf("unable to bump fee: %v", err)
-	}
+	bob.RPC.BumpFee(bumpFeeReq)
 
 	// We should now expect to see two transactions within the mempool, a
 	// parent and its child.
-	_, err = waitForNTxsInMempool(net.Miner.Client, 2, minerMempoolTimeout)
-	if err != nil {
-		t.Fatalf("expected two mempool transactions: %v", err)
-	}
+	ht.Miner.AssertNumTxsInMempool(2)
 
 	// We should also expect to see the output being swept by the
 	// UtxoSweeper. We'll ensure it's using the fee rate specified.
-	pendingSweepsReq := &walletrpc.PendingSweepsRequest{}
-	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
-	pendingSweepsResp, err := bob.WalletKitClient.PendingSweeps(
-		ctxt, pendingSweepsReq,
-	)
-	if err != nil {
-		t.Fatalf("unable to retrieve pending sweeps: %v", err)
-	}
-	if len(pendingSweepsResp.PendingSweeps) != 1 {
-		t.Fatalf("expected to find %v pending sweep(s), found %v", 1,
-			len(pendingSweepsResp.PendingSweeps))
-	}
+	pendingSweepsResp := bob.RPC.PendingSweeps()
+	require.Len(ht, pendingSweepsResp.PendingSweeps, 1,
+		"expected to find 1 pending sweep")
 	pendingSweep := pendingSweepsResp.PendingSweeps[0]
-	if !bytes.Equal(pendingSweep.Outpoint.TxidBytes, op.TxidBytes) {
-		t.Fatalf("expected output txid %x, got %x", op.TxidBytes,
-			pendingSweep.Outpoint.TxidBytes)
-	}
-	if pendingSweep.Outpoint.OutputIndex != op.OutputIndex {
-		t.Fatalf("expected output index %v, got %v", op.OutputIndex,
-			pendingSweep.Outpoint.OutputIndex)
-	}
-	if pendingSweep.SatPerVbyte != bumpFeeReq.SatPerVbyte {
-		t.Fatalf("expected sweep sat per vbyte %v, got %v",
-			bumpFeeReq.SatPerVbyte, pendingSweep.SatPerVbyte)
-	}
+	require.Equal(ht, pendingSweep.Outpoint.TxidBytes, op.TxidBytes,
+		"output txid not matched")
+	require.Equal(ht, pendingSweep.Outpoint.OutputIndex, op.OutputIndex,
+		"output index not matched")
+	require.Equal(ht, pendingSweep.SatPerVbyte, bumpFeeReq.SatPerVbyte,
+		"sweep sat per vbyte not matched")
 
 	// Mine a block to clean up the unconfirmed transactions.
-	mineBlocks(t, net, 1, 2)
+	ht.MineBlocksAndAssertNumTxes(1, 2)
 
 	// The input used to CPFP should no longer be pending.
-	err = wait.NoError(func() error {
-		req := &walletrpc.PendingSweepsRequest{}
-		ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
-		resp, err := bob.WalletKitClient.PendingSweeps(ctxt, req)
-		if err != nil {
-			return fmt.Errorf("unable to retrieve bob's pending "+
-				"sweeps: %v", err)
-		}
+	err := wait.NoError(func() error {
+		resp := bob.RPC.PendingSweeps()
 		if len(resp.PendingSweeps) != 0 {
 			return fmt.Errorf("expected 0 pending sweeps, found %d",
 				len(resp.PendingSweeps))
 		}
 		return nil
 	}, defaultTimeout)
-	if err != nil {
-		t.Fatalf(err.Error())
-	}
+	require.NoError(ht, err, "timeout checking bob's pending sweeps")
 }
 
 // testAnchorReservedValue tests that we won't allow sending transactions when

lntest/itest/lnd_open_channel_test.go

@@ -1,9 +1,8 @@
 package itest
 
 import (
-	"context"
 	"fmt"
-	"time"
+	"testing"
 
 	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
@@ -12,7 +11,8 @@ import (
 	"github.com/lightningnetwork/lnd/funding"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntemp"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp/node"
+	"github.com/lightningnetwork/lnd/lntemp/rpc"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/stretchr/testify/require"
 )
@@ -172,9 +172,7 @@ func testOpenChannelAfterReorg(ht *lntemp.HarnessTest) {
 // ChannelUpdate --> defaultBaseFee, provided FeeRate
 // 4.) baseFee and feeRate provided to OpenChannelRequest
 // ChannelUpdate --> provided baseFee, provided feeRate.
-func testOpenChannelUpdateFeePolicy(net *lntest.NetworkHarness,
-	t *harnessTest) {
-
+func testOpenChannelUpdateFeePolicy(ht *lntemp.HarnessTest) {
 	const (
 		defaultBaseFee       = 1000
 		defaultFeeRate       = 1
@@ -189,7 +187,7 @@ func testOpenChannelUpdateFeePolicy(net *lntest.NetworkHarness,
 	chanAmt := funding.MaxBtcFundingAmount
 	pushAmt := chanAmt / 2
 
-	feeScenarios := []lntest.OpenChannelParams{
+	feeScenarios := []lntemp.OpenChannelParams{
 		{
 			Amt:        chanAmt,
 			PushAmt:    pushAmt,
@@ -259,89 +257,79 @@ func testOpenChannelUpdateFeePolicy(net *lntest.NetworkHarness,
 		MaxHtlcMsat:      defaultMaxHtlc,
 	}
 
-	for i, feeScenario := range feeScenarios {
+	alice, bob := ht.Alice, ht.Bob
+
+	runTestCase := func(ht *lntemp.HarnessTest,
+		fs lntemp.OpenChannelParams,
+		alicePolicy, bobPolicy *lnrpc.RoutingPolicy) {
+
 		// Create a channel Alice->Bob.
-		chanPoint := openChannelAndAssert(
-			t, net, net.Alice, net.Bob,
-			feeScenario,
-		)
+		chanPoint := ht.OpenChannel(alice, bob, fs)
+		defer ht.CloseChannel(alice, chanPoint)
 
-		defer closeChannelAndAssert(t, net, net.Alice, chanPoint, false)
+		// We add all the nodes' update channels to a slice, such that
+		// we can make sure they all receive the expected updates.
+		nodes := []*node.HarnessNode{alice, bob}
 
-		// We add all the nodes' update channels to a slice, such that we can
-		// make sure they all receive the expected updates.
-		nodes := []*lntest.HarnessNode{net.Alice, net.Bob}
-
-		// Alice and Bob should see each other's ChannelUpdates, advertising
-		// the preferred routing policies.
-		assertPolicyUpdate(
-			t, nodes, net.Alice.PubKeyStr,
-			&expectedPolicies[i], chanPoint,
-		)
-		assertPolicyUpdate(
-			t, nodes, net.Bob.PubKeyStr,
-			&bobExpectedPolicy, chanPoint,
+		// Alice and Bob should see each other's ChannelUpdates,
+		// advertising the preferred routing policies.
+		assertNodesPolicyUpdate(
+			ht, nodes, alice, alicePolicy, chanPoint,
 		)
+		assertNodesPolicyUpdate(ht, nodes, bob, bobPolicy, chanPoint)
 
 		// They should now know about the default policies.
 		for _, node := range nodes {
-			assertChannelPolicy(
-				t, node, net.Alice.PubKeyStr,
-				&expectedPolicies[i], chanPoint,
+			ht.AssertChannelPolicy(
+				node, alice.PubKeyStr, alicePolicy, chanPoint,
 			)
-			assertChannelPolicy(
-				t, node, net.Bob.PubKeyStr,
-				&bobExpectedPolicy, chanPoint,
+			ht.AssertChannelPolicy(
+				node, bob.PubKeyStr, bobPolicy, chanPoint,
 			)
 		}
+	}
 
-		require.NoError(
-			t.t, net.Alice.WaitForNetworkChannelOpen(chanPoint),
-			"alice reports channel opening",
-		)
+	for i, feeScenario := range feeScenarios {
+		ht.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			st := ht.Subtest(t)
+			ht.EnsureConnected(alice, bob)
 
-		require.NoError(
-			t.t, net.Bob.WaitForNetworkChannelOpen(chanPoint),
-			"bob reports channel opening",
-		)
+			runTestCase(
+				st, feeScenario,
+				&expectedPolicies[i], &bobExpectedPolicy,
+			)
+		})
 	}
 }
 
 // testBasicChannelCreationAndUpdates tests multiple channel opening and
-// closing, and ensures that if a node is subscribed to channel updates
-// they will be received correctly for both cooperative and force closed
-// channels.
-func testBasicChannelCreationAndUpdates(net *lntest.NetworkHarness,
-	t *harnessTest) {
-
-	runBasicChannelCreationAndUpdates(net, t, net.Alice, net.Bob)
+// closing, and ensures that if a node is subscribed to channel updates they
+// will be received correctly for both cooperative and force closed channels.
+func testBasicChannelCreationAndUpdates(ht *lntemp.HarnessTest) {
+	runBasicChannelCreationAndUpdates(ht, ht.Alice, ht.Bob)
 }
 
 // runBasicChannelCreationAndUpdates tests multiple channel opening and closing,
 // and ensures that if a node is subscribed to channel updates they will be
 // received correctly for both cooperative and force closed channels.
-func runBasicChannelCreationAndUpdates(net *lntest.NetworkHarness,
-	t *harnessTest, alice, bob *lntest.HarnessNode) {
+func runBasicChannelCreationAndUpdates(ht *lntemp.HarnessTest,
+	alice, bob *node.HarnessNode) {
 
-	ctxb := context.Background()
 	const (
 		numChannels = 2
 		amount      = funding.MaxBtcFundingAmount
 	)
 
 	// Subscribe Bob and Alice to channel event notifications.
-	bobChanSub := subscribeChannelNotifications(ctxb, t, bob)
-	defer close(bobChanSub.quit)
-
-	aliceChanSub := subscribeChannelNotifications(ctxb, t, alice)
-	defer close(aliceChanSub.quit)
+	bobChanSub := bob.RPC.SubscribeChannelEvents()
+	aliceChanSub := alice.RPC.SubscribeChannelEvents()
 
 	// Open the channels between Alice and Bob, asserting that the channels
 	// have been properly opened on-chain.
 	chanPoints := make([]*lnrpc.ChannelPoint, numChannels)
 	for i := 0; i < numChannels; i++ {
-		chanPoints[i] = openChannelAndAssert(
-			t, net, alice, bob, lntest.OpenChannelParams{
+		chanPoints[i] = ht.OpenChannel(
+			alice, bob, lntemp.OpenChannelParams{
 				Amt: amount,
 			},
 		)
@@ -350,112 +338,93 @@ func runBasicChannelCreationAndUpdates(net *lntest.NetworkHarness,
 	// Since each of the channels just became open, Bob and Alice should
 	// each receive an open and an active notification for each channel.
 	const numExpectedOpenUpdates = 3 * numChannels
-	verifyOpenUpdatesReceived := func(sub channelSubscription) error {
-		numChannelUpds := 0
-		for numChannelUpds < numExpectedOpenUpdates {
-			select {
-			case update := <-sub.updateChan:
-				switch update.Type {
-				case lnrpc.ChannelEventUpdate_PENDING_OPEN_CHANNEL:
-					if numChannelUpds%3 != 0 {
-						return fmt.Errorf("expected " +
-							"open or active" +
-							"channel ntfn, got pending open " +
-							"channel ntfn instead")
-					}
-				case lnrpc.ChannelEventUpdate_OPEN_CHANNEL:
-					if numChannelUpds%3 != 1 {
-						return fmt.Errorf("expected " +
-							"pending open or active" +
-							"channel ntfn, got open" +
-							"channel ntfn instead")
-					}
-				case lnrpc.ChannelEventUpdate_ACTIVE_CHANNEL:
-					if numChannelUpds%3 != 2 {
-						return fmt.Errorf("expected " +
-							"pending open or open" +
-							"channel ntfn, got active " +
-							"channel ntfn instead")
-					}
-				default:
-					return fmt.Errorf("update type mismatch: "+
-						"expected open or active channel "+
-						"notification, got: %v",
-						update.Type)
-				}
-				numChannelUpds++
+	verifyOpenUpdatesReceived := func(sub rpc.ChannelEventsClient) error {
+		for i := 0; i < numExpectedOpenUpdates; i++ {
+			update := ht.ReceiveChannelEvent(sub)
 
-			case <-time.After(time.Second * 10):
-				return fmt.Errorf("timeout waiting for channel "+
-					"notifications, only received %d/%d "+
-					"chanupds", numChannelUpds,
-					numExpectedOpenUpdates)
+			switch update.Type {
+			case lnrpc.ChannelEventUpdate_PENDING_OPEN_CHANNEL:
+				if i%3 == 0 {
+					continue
+				}
+
+				return fmt.Errorf("expected open or active" +
+					"channel ntfn, got pending open " +
+					"channel ntfn instead")
+
+			case lnrpc.ChannelEventUpdate_OPEN_CHANNEL:
+				if i%3 == 1 {
+					continue
+				}
+
+				return fmt.Errorf("expected pending open or " +
+					"active channel ntfn, got open" +
+					"channel ntfn instead")
+
+			case lnrpc.ChannelEventUpdate_ACTIVE_CHANNEL:
+				if i%3 == 2 {
+					continue
+				}
+
+				return fmt.Errorf("expected pending open or " +
+					"open channel ntfn, got active " +
+					"channel ntfn instead")
+
+			default:
+				return fmt.Errorf("update type mismatch: "+
+					"expected open or active channel "+
+					"notification, got: %v", update.Type)
 			}
 		}
 
 		return nil
 	}
 
-	require.NoError(
-		t.t, verifyOpenUpdatesReceived(bobChanSub), "bob open channels",
-	)
-	require.NoError(
-		t.t, verifyOpenUpdatesReceived(aliceChanSub), "alice open "+
-			"channels",
-	)
+	require.NoError(ht, verifyOpenUpdatesReceived(bobChanSub),
+		"bob open channels")
+	require.NoError(ht, verifyOpenUpdatesReceived(aliceChanSub),
+		"alice open channels")
 
-	// Close the channels between Alice and Bob, asserting that the channels
-	// have been properly closed on-chain.
+	// Close the channels between Alice and Bob, asserting that the
+	// channels have been properly closed on-chain.
 	for i, chanPoint := range chanPoints {
 		// Force close the first of the two channels.
 		force := i%2 == 0
-		closeChannelAndAssert(t, net, alice, chanPoint, force)
 		if force {
-			cleanupForceClose(t, net, alice, chanPoint)
+			ht.ForceCloseChannel(alice, chanPoint)
+		} else {
+			ht.CloseChannel(alice, chanPoint)
 		}
 	}
 
 	// verifyCloseUpdatesReceived is used to verify that Alice and Bob
 	// receive the correct channel updates in order.
 	const numExpectedCloseUpdates = 3 * numChannels
-	verifyCloseUpdatesReceived := func(sub channelSubscription,
+	verifyCloseUpdatesReceived := func(sub rpc.ChannelEventsClient,
 		forceType lnrpc.ChannelCloseSummary_ClosureType,
 		closeInitiator lnrpc.Initiator) error {
 
 		// Ensure one inactive and one closed notification is received
 		// for each closed channel.
-		numChannelUpds := 0
-		for numChannelUpds < numExpectedCloseUpdates {
-			expectedCloseType := lnrpc.ChannelCloseSummary_COOPERATIVE_CLOSE
+		for i := 0; i < numExpectedCloseUpdates; i++ {
+			expectedCloseType := lnrpc.
+				ChannelCloseSummary_COOPERATIVE_CLOSE
 
 			// Every other channel should be force closed. If this
 			// channel was force closed, set the expected close type
 			// to the type passed in.
-			force := (numChannelUpds/3)%2 == 0
+			force := (i/3)%2 == 0
 			if force {
 				expectedCloseType = forceType
 			}
 
-			select {
-			case chanUpdate := <-sub.updateChan:
-				err := verifyCloseUpdate(
-					chanUpdate, expectedCloseType,
-					closeInitiator,
-				)
-				if err != nil {
-					return err
-				}
-
-				numChannelUpds++
-
-			case err := <-sub.errChan:
+			chanUpdate := ht.ReceiveChannelEvent(sub)
+			err := verifyCloseUpdate(
+				chanUpdate, expectedCloseType,
+				closeInitiator,
+			)
+			if err != nil {
 				return err
-
-			case <-time.After(time.Second * 10):
-				return fmt.Errorf("timeout waiting "+
-					"for channel notifications, only "+
-					"received %d/%d chanupds",
-					numChannelUpds, numChannelUpds)
 			}
 		}
 
@@ -467,7 +436,7 @@ func runBasicChannelCreationAndUpdates(net *lntest.NetworkHarness,
 	// All channels (cooperatively and force closed) should have a remote
 	// close initiator because Alice closed the channels.
 	require.NoError(
-		t.t, verifyCloseUpdatesReceived(
+		ht, verifyCloseUpdatesReceived(
 			bobChanSub,
 			lnrpc.ChannelCloseSummary_REMOTE_FORCE_CLOSE,
 			lnrpc.Initiator_INITIATOR_REMOTE,
@@ -479,7 +448,7 @@ func runBasicChannelCreationAndUpdates(net *lntest.NetworkHarness,
 	// All channels (cooperatively and force closed) should have a local
 	// close initiator because Alice closed the channels.
 	require.NoError(
-		t.t, verifyCloseUpdatesReceived(
+		ht, verifyCloseUpdatesReceived(
 			aliceChanSub,
 			lnrpc.ChannelCloseSummary_LOCAL_FORCE_CLOSE,
 			lnrpc.Initiator_INITIATOR_LOCAL,
@@ -516,3 +485,64 @@ func assertMinerBlockHeightDelta(ht *lntemp.HarnessTest,
 	}, defaultTimeout)
 	require.NoError(ht, err, "failed to assert block height delta")
 }
+
+// verifyCloseUpdate is used to verify that a closed channel update is of the
+// expected type.
+func verifyCloseUpdate(chanUpdate *lnrpc.ChannelEventUpdate,
+	closeType lnrpc.ChannelCloseSummary_ClosureType,
+	closeInitiator lnrpc.Initiator) error {
+
+	// We should receive one inactive and one closed notification
+	// for each channel.
+	switch update := chanUpdate.Channel.(type) {
+	case *lnrpc.ChannelEventUpdate_InactiveChannel:
+		if chanUpdate.Type !=
+			lnrpc.ChannelEventUpdate_INACTIVE_CHANNEL {
+
+			return fmt.Errorf("update type mismatch: "+
+				"expected %v, got %v",
+				lnrpc.ChannelEventUpdate_INACTIVE_CHANNEL,
+				chanUpdate.Type)
+		}
+
+	case *lnrpc.ChannelEventUpdate_ClosedChannel:
+		if chanUpdate.Type !=
+			lnrpc.ChannelEventUpdate_CLOSED_CHANNEL {
+
+			return fmt.Errorf("update type mismatch: "+
+				"expected %v, got %v",
+				lnrpc.ChannelEventUpdate_CLOSED_CHANNEL,
+				chanUpdate.Type)
+		}
+
+		if update.ClosedChannel.CloseType != closeType {
+			return fmt.Errorf("channel closure type "+
+				"mismatch: expected %v, got %v",
+				closeType,
+				update.ClosedChannel.CloseType)
+		}
+
+		if update.ClosedChannel.CloseInitiator != closeInitiator {
+			return fmt.Errorf("expected close intiator: %v, "+
+				"got: %v", closeInitiator,
+				update.ClosedChannel.CloseInitiator)
+		}
+
+	case *lnrpc.ChannelEventUpdate_FullyResolvedChannel:
+		if chanUpdate.Type !=
+			lnrpc.ChannelEventUpdate_FULLY_RESOLVED_CHANNEL {
+
+			return fmt.Errorf("update type mismatch: "+
+				"expected %v, got %v",
+				lnrpc.ChannelEventUpdate_FULLY_RESOLVED_CHANNEL,
+				chanUpdate.Type)
+		}
+
+	default:
+		return fmt.Errorf("channel update channel of wrong type, "+
+			"expected closed channel, got %T",
+			update)
+	}
+
+	return nil
+}

lntest/itest/lnd_payment_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
 	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/stretchr/testify/require"
@@ -225,35 +226,31 @@ func testPaymentFollowingChannelOpen(ht *lntemp.HarnessTest) {
 }
 
 // testAsyncPayments tests the performance of the async payments.
-func testAsyncPayments(net *lntest.NetworkHarness, t *harnessTest) {
-	runAsyncPayments(net, t, net.Alice, net.Bob)
+func testAsyncPayments(ht *lntemp.HarnessTest) {
+	// We use new nodes here as the benchmark test creates lots of data
+	// which can be costly to be carried on.
+	alice := ht.NewNode("Alice", []string{"--pending-commit-interval=3m"})
+	bob := ht.NewNode("Bob", []string{"--pending-commit-interval=3m"})
+
+	ht.EnsureConnected(alice, bob)
+	ht.FundCoins(btcutil.SatoshiPerBitcoin, alice)
+
+	runAsyncPayments(ht, alice, bob)
 }
 
 // runAsyncPayments tests the performance of the async payments.
-func runAsyncPayments(net *lntest.NetworkHarness, t *harnessTest, alice,
-	bob *lntest.HarnessNode) {
-
-	ctxb := context.Background()
-
-	const (
-		paymentAmt = 100
-	)
+func runAsyncPayments(ht *lntemp.HarnessTest, alice, bob *node.HarnessNode) {
+	const paymentAmt = 100
 
 	// First establish a channel with a capacity equals to the overall
 	// amount of payments, between Alice and Bob, at the end of the test
 	// Alice should send all money from her side to Bob.
 	channelCapacity := btcutil.Amount(paymentAmt * 2000)
-	chanPoint := openChannelAndAssert(
-		t, net, alice, bob,
-		lntest.OpenChannelParams{
-			Amt: channelCapacity,
-		},
+	chanPoint := ht.OpenChannel(
+		alice, bob, lntemp.OpenChannelParams{Amt: channelCapacity},
 	)
 
-	info, err := getChanInfo(alice)
-	if err != nil {
-		t.Fatalf("unable to get alice channel info: %v", err)
-	}
+	info := ht.QueryChannelByChanPoint(alice, chanPoint)
 
 	// We'll create a number of invoices equal the max number of HTLCs that
 	// can be carried in one direction. The number on the commitment will
@@ -267,128 +264,95 @@ func runAsyncPayments(net *lntest.NetworkHarness, t *harnessTest, alice,
 
 	// With the channel open, we'll create invoices for Bob that Alice
 	// will pay to in order to advance the state of the channel.
-	bobPayReqs, _, _, err := createPayReqs(
-		bob, paymentAmt, numInvoices,
-	)
-	if err != nil {
-		t.Fatalf("unable to create pay reqs: %v", err)
-	}
+	bobPayReqs, _, _ := ht.CreatePayReqs(bob, paymentAmt, numInvoices)
 
-	// Wait for Alice to receive the channel edge from the funding manager.
-	err = alice.WaitForNetworkChannelOpen(chanPoint)
-	if err != nil {
-		t.Fatalf("alice didn't see the alice->bob channel before "+
-			"timeout: %v", err)
-	}
-
-	// Simultaneously send payments from Alice to Bob using of Bob's payment
-	// hashes generated above.
+	// Simultaneously send payments from Alice to Bob using of Bob's
+	// payment hashes generated above.
 	now := time.Now()
-	errChan := make(chan error)
-	statusChan := make(chan *lnrpc.Payment)
+
+	settled := make(chan struct{})
+	defer close(settled)
+
+	timeout := lntest.AsyncBenchmarkTimeout * 2
 	for i := 0; i < numInvoices; i++ {
 		payReq := bobPayReqs[i]
 		go func() {
-			ctxt, _ := context.WithTimeout(ctxb, lntest.AsyncBenchmarkTimeout)
-			stream, err := alice.RouterClient.SendPaymentV2(
-				ctxt,
-				&routerrpc.SendPaymentRequest{
-					PaymentRequest: payReq,
-					TimeoutSeconds: 60,
-					FeeLimitMsat:   noFeeLimitMsat,
-				},
-			)
-			if err != nil {
-				errChan <- err
-			}
-			result, err := getPaymentResult(stream)
-			if err != nil {
-				errChan <- err
+			req := &routerrpc.SendPaymentRequest{
+				PaymentRequest: payReq,
+				TimeoutSeconds: int32(timeout.Seconds()),
+				FeeLimitMsat:   noFeeLimitMsat,
 			}
+			// AssertPaymentStatusWithTimeout will assert that the
+			// payment is settled.
+			stream := alice.RPC.SendPayment(req)
+			ht.AssertPaymentSucceedWithTimeout(stream, timeout)
 
-			statusChan <- result
+			settled <- struct{}{}
 		}()
 	}
 
 	// Wait until all the payments have settled.
+	timer := time.After(timeout)
 	for i := 0; i < numInvoices; i++ {
 		select {
-		case result := <-statusChan:
-			if result.Status == lnrpc.Payment_SUCCEEDED {
-				continue
-			}
-
-		case err := <-errChan:
-			t.Fatalf("payment error: %v", err)
+		case <-settled:
+		case <-timer:
+			require.Fail(ht, "timeout", "wait payment failed")
 		}
 	}
 
 	// All payments have been sent, mark the finish time.
 	timeTaken := time.Since(now)
 
-	// Next query for Bob's and Alice's channel states, in order to confirm
-	// that all payment have been successful transmitted.
+	// assertChannelState asserts the channel state by checking the values
+	// in fields, LocalBalance, RemoteBalance and num of PendingHtlcs.
+	assertChannelState := func(hn *node.HarnessNode, cp *lnrpc.ChannelPoint,
+		localBalance, remoteBalance int64, numPendingHtlcs int) {
 
-	// Wait for the revocation to be received so alice no longer has pending
-	// htlcs listed and has correct balances. This is needed due to the fact
-	// that we now pipeline the settles.
-	err = wait.Predicate(func() bool {
-		aliceChan, err := getChanInfo(alice)
-		if err != nil {
-			return false
-		}
-		if len(aliceChan.PendingHtlcs) != 0 {
-			return false
-		}
-		if aliceChan.RemoteBalance != bobAmt {
-			return false
-		}
-		if aliceChan.LocalBalance != aliceAmt {
-			return false
-		}
+		// Get the funding point.
+		err := wait.NoError(func() error {
+			// Find the target channel first.
+			target := ht.GetChannelByChanPoint(hn, cp)
 
-		return true
-	}, defaultTimeout)
-	if err != nil {
-		t.Fatalf("failed to assert alice's pending htlcs and/or remote/local balance")
+			if len(target.PendingHtlcs) != numPendingHtlcs {
+				return fmt.Errorf("pending htlcs is "+
+					"incorrect, got %v, expected %v",
+					len(target.PendingHtlcs), 0)
+			}
+
+			if target.LocalBalance != localBalance {
+				return fmt.Errorf("local balance is "+
+					"incorrect, got %v, expected %v",
+					target.LocalBalance, localBalance)
+			}
+
+			if target.RemoteBalance != remoteBalance {
+				return fmt.Errorf("remote balance is "+
+					"incorrect, got %v, expected %v",
+					target.RemoteBalance, remoteBalance)
+			}
+
+			return nil
+		}, lntemp.DefaultTimeout)
+		require.NoError(ht, err, "timeout while chekcing for balance")
 	}
 
+	// Wait for the revocation to be received so alice no longer has
+	// pending htlcs listed and has correct balances. This is needed due to
+	// the fact that we now pipeline the settles.
+	assertChannelState(alice, chanPoint, aliceAmt, bobAmt, 0)
+
 	// Wait for Bob to receive revocation from Alice.
-	err = wait.NoError(func() error {
-		bobChan, err := getChanInfo(bob)
-		if err != nil {
-			t.Fatalf("unable to get bob's channel info: %v", err)
-		}
+	assertChannelState(bob, chanPoint, bobAmt, aliceAmt, 0)
 
-		if len(bobChan.PendingHtlcs) != 0 {
-			return fmt.Errorf("bob's pending htlcs is incorrect, "+
-				"got %v, expected %v",
-				len(bobChan.PendingHtlcs), 0)
-		}
-
-		if bobChan.LocalBalance != bobAmt {
-			return fmt.Errorf("bob's local balance is incorrect, "+
-				"got %v, expected %v", bobChan.LocalBalance,
-				bobAmt)
-		}
-
-		if bobChan.RemoteBalance != aliceAmt {
-			return fmt.Errorf("bob's remote balance is incorrect, "+
-				"got %v, expected %v", bobChan.RemoteBalance,
-				aliceAmt)
-		}
-
-		return nil
-	}, defaultTimeout)
-	require.NoError(t.t, err)
-
-	t.Log("\tBenchmark info: Elapsed time: ", timeTaken)
-	t.Log("\tBenchmark info: TPS: ", float64(numInvoices)/timeTaken.Seconds())
+	ht.Log("\tBenchmark info: Elapsed time: ", timeTaken)
+	ht.Log("\tBenchmark info: TPS: ",
+		float64(numInvoices)/timeTaken.Seconds())
 
 	// Finally, immediately close the channel. This function will also
 	// block until the channel is closed and will additionally assert the
 	// relevant channel closing post conditions.
-	closeChannelAndAssert(t, net, alice, chanPoint, false)
+	ht.CloseChannel(alice, chanPoint)
 }
 
 // testBidirectionalAsyncPayments tests that nodes are able to send the

lntest/itest/lnd_remote_signer_test.go

@@ -1,7 +1,6 @@
 package itest
 
 import (
-	"context"
 	"fmt"
 	"testing"
 
@@ -11,7 +10,8 @@ import (
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/stretchr/testify/require"
 )
 
@@ -54,105 +54,94 @@ var (
 
 // testRemoteSigner tests that a watch-only wallet can use a remote signing
 // wallet to perform any signing or ECDH operations.
-func testRemoteSigner(net *lntest.NetworkHarness, t *harnessTest) {
-	ctxb := context.Background()
-
-	subTests := []struct {
+func testRemoteSigner(ht *lntemp.HarnessTest) {
+	type testCase struct {
 		name       string
 		randomSeed bool
 		sendCoins  bool
-		fn         func(tt *harnessTest, wo, carol *lntest.HarnessNode)
-	}{{
+		fn         func(tt *lntemp.HarnessTest,
+			wo, carol *node.HarnessNode)
+	}
+
+	subTests := []testCase{{
 		name:       "random seed",
 		randomSeed: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
 			// Nothing more to test here.
 		},
 	}, {
 		name: "account import",
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
 			runWalletImportAccountScenario(
-				net, tt,
-				walletrpc.AddressType_WITNESS_PUBKEY_HASH,
+				tt, walletrpc.AddressType_WITNESS_PUBKEY_HASH,
 				carol, wo,
 			)
 		},
 	}, {
 		name:      "basic channel open close",
 		sendCoins: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runBasicChannelCreationAndUpdates(
-				net, tt, wo, carol,
-			)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runBasicChannelCreationAndUpdates(tt, wo, carol)
 		},
 	}, {
 		name:      "async payments",
 		sendCoins: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runAsyncPayments(net, tt, wo, carol)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runAsyncPayments(tt, wo, carol)
 		},
 	}, {
 		name: "shared key",
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
 			runDeriveSharedKey(tt, wo)
 		},
 	}, {
 		name:      "cpfp",
 		sendCoins: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runCPFP(net, tt, wo, carol)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runCPFP(tt, wo, carol)
 		},
 	}, {
 		name:       "psbt",
 		randomSeed: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runPsbtChanFunding(net, tt, carol, wo)
-			runSignPsbtSegWitV0P2WKH(tt, net, wo)
-			runSignPsbtSegWitV1KeySpendBip86(tt, net, wo)
-			runSignPsbtSegWitV1KeySpendRootHash(tt, net, wo)
-			runSignPsbtSegWitV1ScriptSpend(tt, net, wo)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runPsbtChanFunding(tt, carol, wo)
+			runSignPsbtSegWitV0P2WKH(tt, wo)
+			runSignPsbtSegWitV1KeySpendBip86(tt, wo)
+			runSignPsbtSegWitV1KeySpendRootHash(tt, wo)
+			runSignPsbtSegWitV1ScriptSpend(tt, wo)
 		},
 	}, {
 		name:      "sign output raw",
 		sendCoins: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runSignOutputRaw(tt, net, wo)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runSignOutputRaw(tt, wo)
 		},
 	}, {
 		name:      "sign verify msg",
 		sendCoins: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			runSignVerifyMessage(tt, net, wo)
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			runSignVerifyMessage(tt, wo)
 		},
 	}, {
 		name:       "taproot",
 		sendCoins:  true,
 		randomSeed: true,
-		fn: func(tt *harnessTest, wo, carol *lntest.HarnessNode) {
-			longTimeout := 3 * defaultTimeout
-			ctxt, cancel := context.WithTimeout(ctxb, longTimeout)
-			testTaprootSendCoinsKeySpendBip86(ctxt, tt, wo, net)
-			testTaprootComputeInputScriptKeySpendBip86(
-				ctxt, tt, wo, net,
-			)
-			testTaprootSignOutputRawScriptSpend(ctxt, tt, wo, net)
-			testTaprootSignOutputRawKeySpendBip86(ctxt, tt, wo, net)
-			testTaprootSignOutputRawKeySpendRootHash(
-				ctxt, tt, wo, net,
-			)
-			cancel()
-
-			ctxt, cancel = context.WithTimeout(ctxb, longTimeout)
-			testTaprootMuSig2KeySpendRootHash(ctxt, tt, wo, net)
-			testTaprootMuSig2ScriptSpend(ctxt, tt, wo, net)
-			testTaprootMuSig2KeySpendBip86(ctxt, tt, wo, net)
-			testTaprootMuSig2CombinedLeafKeySpend(ctxt, tt, wo, net)
-			cancel()
+		fn: func(tt *lntemp.HarnessTest, wo, carol *node.HarnessNode) {
+			testTaprootSendCoinsKeySpendBip86(tt, wo)
+			testTaprootComputeInputScriptKeySpendBip86(tt, wo)
+			testTaprootSignOutputRawScriptSpend(tt, wo)
+			testTaprootSignOutputRawKeySpendBip86(tt, wo)
+			testTaprootSignOutputRawKeySpendRootHash(tt, wo)
+			testTaprootMuSig2KeySpendRootHash(tt, wo)
+			testTaprootMuSig2ScriptSpend(tt, wo)
+			testTaprootMuSig2KeySpendBip86(tt, wo)
+			testTaprootMuSig2CombinedLeafKeySpend(tt, wo)
 		},
 	}}
 
-	for _, st := range subTests {
-		subTest := st
+	prepareTest := func(st *lntemp.HarnessTest,
+		subTest testCase) (*node.HarnessNode,
+		*node.HarnessNode, *node.HarnessNode) {
 
 		// Signer is our signing node and has the wallet with the full
 		// master private key. We test that we can create the watch-only
@@ -162,34 +151,32 @@ func testRemoteSigner(net *lntest.NetworkHarness, t *harnessTest) {
 		password := []byte("itestpassword")
 		var (
 			signerNodePubKey  = nodePubKey
-			watchOnlyAccounts = deriveCustomScopeAccounts(t.t)
-			signer            *lntest.HarnessNode
+			watchOnlyAccounts = deriveCustomScopeAccounts(ht.T)
+			signer            *node.HarnessNode
 			err               error
 		)
 		if !subTest.randomSeed {
-			signer, err = net.RestoreNodeWithSeed(
+			signer = st.RestoreNodeWithSeed(
 				"Signer", nil, password, nil, rootKey, 0, nil,
 			)
-			require.NoError(t.t, err)
 		} else {
-			signer = net.NewNode(t.t, "Signer", nil)
+			signer = st.NewNode("Signer", nil)
 			signerNodePubKey = signer.PubKeyStr
 
-			rpcAccts, err := signer.WalletKitClient.ListAccounts(
-				ctxb, &walletrpc.ListAccountsRequest{},
+			rpcAccts := signer.RPC.ListAccounts(
+				&walletrpc.ListAccountsRequest{},
 			)
-			require.NoError(t.t, err)
 
 			watchOnlyAccounts, err = walletrpc.AccountsToWatchOnly(
 				rpcAccts.Accounts,
 			)
-			require.NoError(t.t, err)
+			require.NoError(st, err)
 		}
 
 		// WatchOnly is the node that has a watch-only wallet and uses
 		// the Signer node for any operation that requires access to
 		// private keys.
-		watchOnly, err := net.NewNodeRemoteSigner(
+		watchOnly := st.NewNodeRemoteSigner(
 			"WatchOnly", []string{
 				"--remotesigner.enable",
 				fmt.Sprintf(
@@ -210,33 +197,35 @@ func testRemoteSigner(net *lntest.NetworkHarness, t *harnessTest) {
 				Accounts:                   watchOnlyAccounts,
 			},
 		)
-		require.NoError(t.t, err)
 
-		resp, err := watchOnly.GetInfo(ctxb, &lnrpc.GetInfoRequest{})
-		require.NoError(t.t, err)
-
-		require.Equal(t.t, signerNodePubKey, resp.IdentityPubkey)
+		resp := watchOnly.RPC.GetInfo()
+		require.Equal(st, signerNodePubKey, resp.IdentityPubkey)
 
 		if subTest.sendCoins {
-			net.SendCoins(t.t, btcutil.SatoshiPerBitcoin, watchOnly)
-			assertAccountBalance(
-				t.t, watchOnly, "default",
+			st.FundCoins(btcutil.SatoshiPerBitcoin, watchOnly)
+			ht.AssertWalletAccountBalance(
+				watchOnly, "default",
 				btcutil.SatoshiPerBitcoin, 0,
 			)
 		}
 
-		carol := net.NewNode(t.t, "carol", nil)
-		net.EnsureConnected(t.t, watchOnly, carol)
+		carol := st.NewNode("carol", nil)
+		st.EnsureConnected(watchOnly, carol)
 
-		success := t.t.Run(subTest.name, func(tt *testing.T) {
-			ht := newHarnessTest(tt, net)
-			subTest.fn(ht, watchOnly, carol)
+		return signer, watchOnly, carol
+	}
+
+	for _, testCase := range subTests {
+		subTest := testCase
+
+		success := ht.Run(subTest.name, func(tt *testing.T) {
+			// Skip the cleanup here as no standby node is used.
+			st := ht.Subtest(tt)
+
+			_, watchOnly, carol := prepareTest(st, subTest)
+			subTest.fn(st, watchOnly, carol)
 		})
 
-		shutdownAndAssert(net, t, carol)
-		shutdownAndAssert(net, t, watchOnly)
-		shutdownAndAssert(net, t, signer)
-
 		if !success {
 			return
 		}

lntest/itest/lnd_rpc_middleware_interceptor_test.go

@@ -560,7 +560,7 @@ func middlewareMandatoryTest(ht *lntemp.HarnessTest, node *node.HarnessNode) {
 	// test case. So we need to do the wait and client setup manually here.
 	conn, err := node.ConnectRPC()
 	require.NoError(ht, err)
-	node.InitRPCClients(conn)
+	node.Initialize(conn)
 	err = node.WaitUntilServerActive()
 	require.NoError(ht, err)
 

lntest/itest/lnd_send_multi_path_payment_test.go

@@ -1,22 +1,19 @@
 package itest
 
 import (
-	"context"
 	"encoding/hex"
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/stretchr/testify/require"
 )
 
 // testSendMultiPathPayment tests that we are able to successfully route a
 // payment using multiple shards across different paths.
-func testSendMultiPathPayment(net *lntest.NetworkHarness, t *harnessTest) {
-	ctxb := context.Background()
-
-	ctx := newMppTestContext(t, net)
-	defer ctx.shutdownNodes()
+func testSendMultiPathPayment(ht *lntemp.HarnessTest) {
+	mts := newMppTestScenario(ht)
 
 	const paymentAmt = btcutil.Amount(300000)
 
@@ -30,57 +27,45 @@ func testSendMultiPathPayment(net *lntest.NetworkHarness, t *harnessTest) {
 	//      \              /
 	//       \__ Dave ____/
 	//
-	ctx.openChannel(ctx.carol, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.carol, 235000)
-	ctx.openChannel(ctx.dave, ctx.bob, 135000)
-	ctx.openChannel(ctx.alice, ctx.dave, 135000)
-	ctx.openChannel(ctx.eve, ctx.bob, 135000)
-	ctx.openChannel(ctx.carol, ctx.eve, 135000)
-
-	defer ctx.closeChannels()
-
-	ctx.waitForChannels()
+	req := &mppOpenChannelRequest{
+		amtAliceCarol: 235000,
+		amtAliceDave:  135000,
+		amtCarolBob:   135000,
+		amtCarolEve:   135000,
+		amtDaveBob:    135000,
+		amtEveBob:     135000,
+	}
+	mts.openChannels(req)
+	chanPointAliceDave := mts.channelPoints[1]
 
 	// Increase Dave's fee to make the test deterministic. Otherwise it
 	// would be unpredictable whether pathfinding would go through Charlie
 	// or Dave for the first shard.
-	_, err := ctx.dave.UpdateChannelPolicy(
-		context.Background(),
-		&lnrpc.PolicyUpdateRequest{
-			Scope:         &lnrpc.PolicyUpdateRequest_Global{Global: true},
-			BaseFeeMsat:   500000,
-			FeeRate:       0.001,
-			TimeLockDelta: 40,
-		},
+	expectedPolicy := mts.updateDaveGlobalPolicy()
+
+	// Make sure Alice has heard it.
+	ht.AssertChannelPolicyUpdate(
+		mts.alice, mts.dave, expectedPolicy, chanPointAliceDave, false,
 	)
-	if err != nil {
-		t.Fatalf("dave policy update: %v", err)
-	}
+
 	// Our first test will be Alice paying Bob using a SendPayment call.
 	// Let Bob create an invoice for Alice to pay.
-	payReqs, rHashes, invoices, err := createPayReqs(
-		ctx.bob, paymentAmt, 1,
-	)
-	if err != nil {
-		t.Fatalf("unable to create pay reqs: %v", err)
-	}
+	payReqs, rHashes, invoices := ht.CreatePayReqs(mts.bob, paymentAmt, 1)
 
 	rHash := rHashes[0]
 	payReq := payReqs[0]
 
-	payment := sendAndAssertSuccess(
-		t, ctx.alice, &routerrpc.SendPaymentRequest{
-			PaymentRequest: payReq,
-			MaxParts:       10,
-			TimeoutSeconds: 60,
-			FeeLimitMsat:   noFeeLimitMsat,
-		},
-	)
+	sendReq := &routerrpc.SendPaymentRequest{
+		PaymentRequest: payReq,
+		MaxParts:       10,
+		TimeoutSeconds: 60,
+		FeeLimitMsat:   noFeeLimitMsat,
+	}
+	payment := ht.SendPaymentAssertSettled(mts.alice, sendReq)
 
 	// Make sure we got the preimage.
-	if payment.PaymentPreimage != hex.EncodeToString(invoices[0].RPreimage) {
-		t.Fatalf("preimage doesn't match")
-	}
+	require.Equal(ht, hex.EncodeToString(invoices[0].RPreimage),
+		payment.PaymentPreimage, "preimage doesn't match")
 
 	// Check that Alice split the payment in at least three shards. Because
 	// the hand-off of the htlc to the link is asynchronous (via a mailbox),
@@ -97,32 +82,17 @@ func testSendMultiPathPayment(net *lntest.NetworkHarness, t *harnessTest) {
 	}
 
 	const minExpectedShards = 3
-	if succeeded < minExpectedShards {
-		t.Fatalf("expected at least %v shards, but got %v",
-			minExpectedShards, succeeded)
-	}
+	require.GreaterOrEqual(ht, succeeded, minExpectedShards,
+		"expected shards not reached")
 
-	// Make sure Bob show the invoice as settled for the full
-	// amount.
-	ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-	inv, err := ctx.bob.LookupInvoice(
-		ctxt, &lnrpc.PaymentHash{
-			RHash: rHash,
-		},
-	)
-	if err != nil {
-		t.Fatalf("error when obtaining invoice: %v", err)
-	}
+	// Make sure Bob show the invoice as settled for the full amount.
+	inv := mts.bob.RPC.LookupInvoice(rHash)
 
-	if inv.AmtPaidSat != int64(paymentAmt) {
-		t.Fatalf("incorrect payment amt for invoice"+
-			"want: %d, got %d",
-			paymentAmt, inv.AmtPaidSat)
-	}
+	require.EqualValues(ht, paymentAmt, inv.AmtPaidSat,
+		"incorrect payment amt")
 
-	if inv.State != lnrpc.Invoice_SETTLED {
-		t.Fatalf("Invoice not settled: %v", inv.State)
-	}
+	require.Equal(ht, lnrpc.Invoice_SETTLED, inv.State,
+		"Invoice not settled")
 
 	settled := 0
 	for _, htlc := range inv.Htlcs {
@@ -130,8 +100,9 @@ func testSendMultiPathPayment(net *lntest.NetworkHarness, t *harnessTest) {
 			settled++
 		}
 	}
-	if settled != succeeded {
-		t.Fatalf("expected invoice to be settled "+
-			"with %v HTLCs, had %v", succeeded, settled)
-	}
+	require.Equal(ht, succeeded, settled,
+		"num of HTLCs wrong")
+
+	// Finally, close all channels.
+	mts.closeChannels()
 }

lntest/itest/lnd_signer_test.go

@@ -2,9 +2,7 @@ package itest
 
 import (
 	"bytes"
-	"context"
 	"crypto/sha256"
-	"fmt"
 
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcec/v2/schnorr"
@@ -15,7 +13,8 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/signrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/stretchr/testify/require"
 )
 
@@ -23,21 +22,19 @@ import (
 // DeriveSharedKey. It creates an ephemeral private key, performing an ECDH with
 // the node's pubkey and a customized public key to check the validity of the
 // result.
-func testDeriveSharedKey(net *lntest.NetworkHarness, t *harnessTest) {
-	runDeriveSharedKey(t, net.Alice)
+func testDeriveSharedKey(ht *lntemp.HarnessTest) {
+	runDeriveSharedKey(ht, ht.Alice)
 }
 
 // runDeriveSharedKey checks the ECDH performed by the endpoint
 // DeriveSharedKey. It creates an ephemeral private key, performing an ECDH with
 // the node's pubkey and a customized public key to check the validity of the
 // result.
-func runDeriveSharedKey(t *harnessTest, alice *lntest.HarnessNode) {
-	ctxb := context.Background()
-
+func runDeriveSharedKey(ht *lntemp.HarnessTest, alice *node.HarnessNode) {
 	// Create an ephemeral key, extracts its public key, and make a
 	// PrivKeyECDH using the ephemeral key.
 	ephemeralPriv, err := btcec.NewPrivateKey()
-	require.NoError(t.t, err, "failed to create ephemeral key")
+	require.NoError(ht, err, "failed to create ephemeral key")
 
 	ephemeralPubBytes := ephemeralPriv.PubKey().SerializeCompressed()
 	privKeyECDH := &keychain.PrivKeyECDH{PrivKey: ephemeralPriv}
@@ -47,30 +44,27 @@ func runDeriveSharedKey(t *harnessTest, alice *lntest.HarnessNode) {
 	assertECDHMatch := func(pub *btcec.PublicKey,
 		req *signrpc.SharedKeyRequest) {
 
-		ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-		resp, err := alice.SignerClient.DeriveSharedKey(ctxt, req)
-		require.NoError(t.t, err, "calling DeriveSharedKey failed")
+		resp := alice.RPC.DeriveSharedKey(req)
 
 		sharedKey, _ := privKeyECDH.ECDH(pub)
-		require.Equal(
-			t.t, sharedKey[:], resp.SharedKey,
-			"failed to derive the expected key",
-		)
+		require.Equal(ht, sharedKey[:], resp.SharedKey,
+			"failed to derive the expected key")
 	}
 
 	nodePub, err := btcec.ParsePubKey(alice.PubKey[:])
-	require.NoError(t.t, err, "failed to parse node pubkey")
+	require.NoError(ht, err, "failed to parse node pubkey")
 
 	customizedKeyFamily := int32(keychain.KeyFamilyMultiSig)
 	customizedIndex := int32(1)
 
-	customizedPub, err := deriveCustomizedKey(
-		ctxb, alice, &signrpc.KeyLocator{
-			KeyFamily: customizedKeyFamily,
-			KeyIndex:  customizedIndex,
-		},
-	)
-	require.NoError(t.t, err, "failed to create customized pubkey")
+	// Derive a customized key.
+	deriveReq := &signrpc.KeyLocator{
+		KeyFamily: customizedKeyFamily,
+		KeyIndex:  customizedIndex,
+	}
+	resp := alice.RPC.DeriveKey(deriveReq)
+	customizedPub, err := btcec.ParsePubKey(resp.RawKeyBytes)
+	require.NoError(ht, err, "failed to parse node pubkey")
 
 	// Test DeriveSharedKey with no optional arguments. It will result in
 	// performing an ECDH between the ephemeral key and the node's pubkey.
@@ -154,12 +148,8 @@ func runDeriveSharedKey(t *harnessTest, alice *lntest.HarnessNode) {
 	// assertErrorMatch checks when calling DeriveSharedKey with invalid
 	// params, the expected error is returned.
 	assertErrorMatch := func(match string, req *signrpc.SharedKeyRequest) {
-		ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
-		_, err := alice.SignerClient.DeriveSharedKey(ctxt, req)
-		require.Error(t.t, err, "expected to have an error")
-		require.Contains(
-			t.t, err.Error(), match, "error failed to match",
-		)
+		err := alice.RPC.DeriveSharedKeyErr(req)
+		require.Contains(ht, err.Error(), match, "error not match")
 	}
 
 	// Test that EphemeralPubkey must be supplied.
@@ -204,43 +194,35 @@ func runDeriveSharedKey(t *harnessTest, alice *lntest.HarnessNode) {
 
 // testSignOutputRaw makes sure that the SignOutputRaw RPC can be used with all
 // custom ways of specifying the signing key in the key descriptor/locator.
-func testSignOutputRaw(net *lntest.NetworkHarness, t *harnessTest) {
-	runSignOutputRaw(t, net, net.Alice)
+func testSignOutputRaw(ht *lntemp.HarnessTest) {
+	runSignOutputRaw(ht, ht.Alice)
 }
 
 // runSignOutputRaw makes sure that the SignOutputRaw RPC can be used with all
 // custom ways of specifying the signing key in the key descriptor/locator.
-func runSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
-	alice *lntest.HarnessNode) {
-
-	ctxb := context.Background()
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-
+func runSignOutputRaw(ht *lntemp.HarnessTest, alice *node.HarnessNode) {
 	// For the next step, we need a public key. Let's use a special family
 	// for this. We want this to be an index of zero.
 	const testCustomKeyFamily = 44
-	keyDesc, err := alice.WalletKitClient.DeriveNextKey(
-		ctxt, &walletrpc.KeyReq{
-			KeyFamily: testCustomKeyFamily,
-		},
-	)
-	require.NoError(t.t, err)
-	require.Equal(t.t, int32(0), keyDesc.KeyLoc.KeyIndex)
+	req := &walletrpc.KeyReq{
+		KeyFamily: testCustomKeyFamily,
+	}
+	keyDesc := alice.RPC.DeriveNextKey(req)
+	require.Equal(ht, int32(0), keyDesc.KeyLoc.KeyIndex)
 
 	targetPubKey, err := btcec.ParsePubKey(keyDesc.RawKeyBytes)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	// First, try with a key descriptor that only sets the public key.
 	assertSignOutputRaw(
-		t, net, alice, targetPubKey, &signrpc.KeyDescriptor{
+		ht, alice, targetPubKey, &signrpc.KeyDescriptor{
 			RawKeyBytes: keyDesc.RawKeyBytes,
 		},
 	)
 
 	// Now try again, this time only with the (0 index!) key locator.
 	assertSignOutputRaw(
-		t, net, alice, targetPubKey, &signrpc.KeyDescriptor{
+		ht, alice, targetPubKey, &signrpc.KeyDescriptor{
 			KeyLoc: &signrpc.KeyLocator{
 				KeyFamily: keyDesc.KeyLoc.KeyFamily,
 				KeyIndex:  keyDesc.KeyLoc.KeyIndex,
@@ -250,29 +232,25 @@ func runSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
 
 	// And now test everything again with a new key where we know the index
 	// is not 0.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	keyDesc, err = alice.WalletKitClient.DeriveNextKey(
-		ctxt, &walletrpc.KeyReq{
-			KeyFamily: testCustomKeyFamily,
-		},
-	)
-	require.NoError(t.t, err)
-	require.Equal(t.t, int32(1), keyDesc.KeyLoc.KeyIndex)
+	req = &walletrpc.KeyReq{
+		KeyFamily: testCustomKeyFamily,
+	}
+	keyDesc = alice.RPC.DeriveNextKey(req)
+	require.Equal(ht, int32(1), keyDesc.KeyLoc.KeyIndex)
 
 	targetPubKey, err = btcec.ParsePubKey(keyDesc.RawKeyBytes)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	// First, try with a key descriptor that only sets the public key.
 	assertSignOutputRaw(
-		t, net, alice, targetPubKey, &signrpc.KeyDescriptor{
+		ht, alice, targetPubKey, &signrpc.KeyDescriptor{
 			RawKeyBytes: keyDesc.RawKeyBytes,
 		},
 	)
 
 	// Now try again, this time only with the key locator.
 	assertSignOutputRaw(
-		t, net, alice, targetPubKey, &signrpc.KeyDescriptor{
+		ht, alice, targetPubKey, &signrpc.KeyDescriptor{
 			KeyLoc: &signrpc.KeyLocator{
 				KeyFamily: keyDesc.KeyLoc.KeyFamily,
 				KeyIndex:  keyDesc.KeyLoc.KeyIndex,
@@ -284,53 +262,44 @@ func runSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
 // assertSignOutputRaw sends coins to a p2wkh address derived from the given
 // target public key and then tries to spend that output again by invoking the
 // SignOutputRaw RPC with the key descriptor provided.
-func assertSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
-	alice *lntest.HarnessNode, targetPubKey *btcec.PublicKey,
+func assertSignOutputRaw(ht *lntemp.HarnessTest,
+	alice *node.HarnessNode, targetPubKey *btcec.PublicKey,
 	keyDesc *signrpc.KeyDescriptor) {
 
-	ctxb := context.Background()
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-
 	pubKeyHash := btcutil.Hash160(targetPubKey.SerializeCompressed())
 	targetAddr, err := btcutil.NewAddressWitnessPubKeyHash(
 		pubKeyHash, harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 	targetScript, err := txscript.PayToAddrScript(targetAddr)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	// Send some coins to the generated p2wpkh address.
-	_, err = alice.SendCoins(ctxt, &lnrpc.SendCoinsRequest{
+	req := &lnrpc.SendCoinsRequest{
 		Addr:   targetAddr.String(),
 		Amount: 800_000,
-	})
-	require.NoError(t.t, err)
+	}
+	alice.RPC.SendCoins(req)
 
 	// Wait until the TX is found in the mempool.
-	txid, err := waitForTxInMempool(net.Miner.Client, minerMempoolTimeout)
-	require.NoError(t.t, err)
+	txid := ht.Miner.AssertNumTxsInMempool(1)[0]
 
-	targetOutputIndex := getOutputIndex(
-		t, net.Miner, txid, targetAddr.String(),
-	)
+	targetOutputIndex := ht.GetOutputIndex(txid, targetAddr.String())
 
 	// Clear the mempool.
-	mineBlocks(t, net, 1, 1)
+	ht.MineBlocksAndAssertNumTxes(1, 1)
 
 	// Try to spend the output now to a new p2wkh address.
-	p2wkhResp, err := alice.NewAddress(ctxt, &lnrpc.NewAddressRequest{
-		Type: lnrpc.AddressType_WITNESS_PUBKEY_HASH,
-	})
-	require.NoError(t.t, err)
+	addrReq := &lnrpc.NewAddressRequest{Type: AddrTypeWitnessPubkeyHash}
+	p2wkhResp := alice.RPC.NewAddress(addrReq)
 
 	p2wkhAdrr, err := btcutil.DecodeAddress(
 		p2wkhResp.Address, harnessNetParams,
 	)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	p2wkhPkScript, err := txscript.PayToAddrScript(p2wkhAdrr)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	tx := wire.NewMsgTx(2)
 	tx.TxIn = []*wire.TxIn{{
@@ -346,24 +315,22 @@ func assertSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
 	}}
 
 	var buf bytes.Buffer
-	require.NoError(t.t, tx.Serialize(&buf))
+	require.NoError(ht, tx.Serialize(&buf))
 
-	signResp, err := alice.SignerClient.SignOutputRaw(
-		ctxt, &signrpc.SignReq{
-			RawTxBytes: buf.Bytes(),
-			SignDescs: []*signrpc.SignDescriptor{{
-				Output: &signrpc.TxOut{
-					PkScript: targetScript,
-					Value:    800_000,
-				},
-				InputIndex:    0,
-				KeyDesc:       keyDesc,
-				Sighash:       uint32(txscript.SigHashAll),
-				WitnessScript: targetScript,
-			}},
-		},
-	)
-	require.NoError(t.t, err)
+	signReq := &signrpc.SignReq{
+		RawTxBytes: buf.Bytes(),
+		SignDescs: []*signrpc.SignDescriptor{{
+			Output: &signrpc.TxOut{
+				PkScript: targetScript,
+				Value:    800_000,
+			},
+			InputIndex:    0,
+			KeyDesc:       keyDesc,
+			Sighash:       uint32(txscript.SigHashAll),
+			WitnessScript: targetScript,
+		}},
+	}
+	signResp := alice.RPC.SignOutputRaw(signReq)
 
 	tx.TxIn[0].Witness = wire.TxWitness{
 		append(signResp.RawSigs[0], byte(txscript.SigHashAll)),
@@ -371,68 +338,38 @@ func assertSignOutputRaw(t *harnessTest, net *lntest.NetworkHarness,
 	}
 
 	buf.Reset()
-	require.NoError(t.t, tx.Serialize(&buf))
+	require.NoError(ht, tx.Serialize(&buf))
 
-	_, err = alice.WalletKitClient.PublishTransaction(
-		ctxt, &walletrpc.Transaction{
-			TxHex: buf.Bytes(),
-		},
-	)
-	require.NoError(t.t, err)
+	alice.RPC.PublishTransaction(&walletrpc.Transaction{
+		TxHex: buf.Bytes(),
+	})
 
 	// Wait until the spending tx is found.
-	txid, err = waitForTxInMempool(net.Miner.Client, minerMempoolTimeout)
-	require.NoError(t.t, err)
-	p2wkhOutputIndex := getOutputIndex(
-		t, net.Miner, txid, p2wkhAdrr.String(),
-	)
+	txid = ht.Miner.AssertNumTxsInMempool(1)[0]
+	p2wkhOutputIndex := ht.GetOutputIndex(txid, p2wkhAdrr.String())
+
 	op := &lnrpc.OutPoint{
 		TxidBytes:   txid[:],
 		OutputIndex: uint32(p2wkhOutputIndex),
 	}
-	assertWalletUnspent(t, alice, op, "")
+	ht.AssertUTXOInWallet(alice, op, "")
 
-	// Mine another block to clean up the mempool and to make sure the spend
-	// tx is actually included in a block.
-	mineBlocks(t, net, 1, 1)
-}
-
-// deriveCustomizedKey uses the family and index to derive a public key from
-// the node's walletkit client.
-func deriveCustomizedKey(ctx context.Context, node *lntest.HarnessNode,
-	keyLoc *signrpc.KeyLocator) (*btcec.PublicKey, error) {
-
-	ctxt, cancel := context.WithTimeout(ctx, defaultTimeout)
-	defer cancel()
-
-	resp, err := node.WalletKitClient.DeriveKey(ctxt, keyLoc)
-	if err != nil {
-		return nil, fmt.Errorf("failed to derive key: %v", err)
-	}
-	pub, err := btcec.ParsePubKey(resp.RawKeyBytes)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse node pubkey: %v", err)
-	}
-	return pub, nil
+	// Mine another block to clean up the mempool and to make sure the
+	// spend tx is actually included in a block.
+	ht.MineBlocksAndAssertNumTxes(1, 1)
 }
 
 // testSignVerifyMessage makes sure that the SignMessage RPC can be used with
 // all custom flags by verifying with VerifyMessage. Tests both ECDSA and
 // Schnorr signatures.
-func testSignVerifyMessage(net *lntest.NetworkHarness, t *harnessTest) {
-	runSignVerifyMessage(t, net, net.Alice)
+func testSignVerifyMessage(ht *lntemp.HarnessTest) {
+	runSignVerifyMessage(ht, ht.Alice)
 }
 
-// runSignVerifyMessage makes sure that the SignMessage RPC can be used with all
-// custom flags by verifying with VerifyMessage. Tests both ECDSA and Schnorr
-// signatures.
-func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
-	alice *lntest.HarnessNode) {
-
-	ctxb := context.Background()
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-
+// runSignVerifyMessage makes sure that the SignMessage RPC can be used with
+// all custom flags by verifying with VerifyMessage. Tests both ECDSA and
+// Schnorr signatures.
+func runSignVerifyMessage(ht *lntemp.HarnessTest, alice *node.HarnessNode) {
 	aliceMsg := []byte("alice msg")
 	keyLoc := &signrpc.KeyLocator{
 		KeyFamily: int32(keychain.KeyFamilyNodeKey),
@@ -446,11 +383,17 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 		SchnorrSig: false,
 	}
 
-	signMsgResp, err := alice.SignerClient.SignMessage(ctxt, signMsgReq)
-	require.NoError(t.t, err, "failed to sign message")
+	signMsgResp := alice.RPC.SignMessageSigner(signMsgReq)
 
-	customPubKey, err := deriveCustomizedKey(ctxt, alice, keyLoc)
-	require.NoError(t.t, err, "failed to create customized pubkey")
+	deriveCustomizedKey := func() *btcec.PublicKey {
+		resp := alice.RPC.DeriveKey(keyLoc)
+		pub, err := btcec.ParsePubKey(resp.RawKeyBytes)
+		require.NoError(ht, err, "failed to parse node pubkey")
+
+		return pub
+	}
+
+	customPubKey := deriveCustomizedKey()
 
 	verifyReq := &signrpc.VerifyMessageReq{
 		Msg:          aliceMsg,
@@ -458,10 +401,8 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 		Pubkey:       customPubKey.SerializeCompressed(),
 		IsSchnorrSig: false,
 	}
-	verifyResp, err := alice.SignerClient.VerifyMessage(ctxt, verifyReq)
-	require.NoError(t.t, err)
-
-	require.True(t.t, verifyResp.Valid, "failed to verify message")
+	verifyResp := alice.RPC.VerifyMessageSigner(verifyReq)
+	require.True(ht, verifyResp.Valid, "failed to verify message")
 
 	// Use a different key locator.
 	keyLoc = &signrpc.KeyLocator{
@@ -475,12 +416,8 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 		KeyLoc:     keyLoc,
 		SchnorrSig: true,
 	}
-
-	signMsgResp, err = alice.SignerClient.SignMessage(ctxt, signMsgReq)
-	require.NoError(t.t, err)
-
-	customPubKey, err = deriveCustomizedKey(ctxt, alice, keyLoc)
-	require.NoError(t.t, err, "failed to create customized pubkey")
+	signMsgResp = alice.RPC.SignMessageSigner(signMsgReq)
+	customPubKey = deriveCustomizedKey()
 
 	// Verify the Schnorr signature.
 	verifyReq = &signrpc.VerifyMessageReq{
@@ -489,10 +426,8 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 		Pubkey:       schnorr.SerializePubKey(customPubKey),
 		IsSchnorrSig: true,
 	}
-	verifyResp, err = alice.SignerClient.VerifyMessage(ctxt, verifyReq)
-	require.NoError(t.t, err)
-
-	require.True(t.t, verifyResp.Valid, "failed to verify message")
+	verifyResp = alice.RPC.VerifyMessageSigner(verifyReq)
+	require.True(ht, verifyResp.Valid, "failed to verify message")
 
 	// Also test that we can tweak a private key and verify the message
 	// against the tweaked public key.
@@ -502,8 +437,7 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 	)
 
 	signMsgReq.SchnorrSigTapTweak = tweakBytes[:]
-	signMsgResp, err = alice.SignerClient.SignMessage(ctxt, signMsgReq)
-	require.NoError(t.t, err)
+	signMsgResp = alice.RPC.SignMessageSigner(signMsgReq)
 
 	verifyReq = &signrpc.VerifyMessageReq{
 		Msg:          aliceMsg,
@@ -511,8 +445,6 @@ func runSignVerifyMessage(t *harnessTest, net *lntest.NetworkHarness,
 		Pubkey:       schnorr.SerializePubKey(tweakedPubKey),
 		IsSchnorrSig: true,
 	}
-	verifyResp, err = alice.SignerClient.VerifyMessage(ctxt, verifyReq)
-	require.NoError(t.t, err)
-
-	require.True(t.t, verifyResp.Valid, "failed to verify message")
+	verifyResp = alice.RPC.VerifyMessageSigner(verifyReq)
+	require.True(ht, verifyResp.Valid, "failed to verify message")
 }

lntest/itest/lnd_test_list_on_test.go

@@ -4,140 +4,8 @@
 package itest
 
 var allTestCases = []*testCase{
-	{
-		name: "multiple channel creation and update subscription",
-		test: testBasicChannelCreationAndUpdates,
-	},
-	{
-		name: "derive shared key",
-		test: testDeriveSharedKey,
-	},
-	{
-		name: "sign output raw",
-		test: testSignOutputRaw,
-	},
-	{
-		name: "sign verify message",
-		test: testSignVerifyMessage,
-	},
-	{
-		name: "async payments benchmark",
-		test: testAsyncPayments,
-	},
 	{
 		name: "async bidirectional payments",
 		test: testBidirectionalAsyncPayments,
 	},
-	{
-		name: "switch circuit persistence",
-		test: testSwitchCircuitPersistence,
-	},
-	{
-		name: "switch offline delivery",
-		test: testSwitchOfflineDelivery,
-	},
-	{
-		name: "switch offline delivery persistence",
-		test: testSwitchOfflineDeliveryPersistence,
-	},
-	{
-		name: "switch offline delivery outgoing offline",
-		test: testSwitchOfflineDeliveryOutgoingOffline,
-	},
-	{
-		name: "cpfp",
-		test: testCPFP,
-	},
-	{
-		name: "psbt channel funding",
-		test: testPsbtChanFunding,
-	},
-	{
-		name: "sign psbt",
-		test: testSignPsbt,
-	},
-	{
-		name: "sendtoroute multi path payment",
-		test: testSendToRouteMultiPath,
-	},
-	{
-		name: "sendtoroute amp",
-		test: testSendToRouteAMP,
-	},
-	{
-		name: "sendpayment amp",
-		test: testSendPaymentAMP,
-	},
-	{
-		name: "sendpayment amp invoice",
-		test: testSendPaymentAMPInvoice,
-	},
-	{
-		name: "sendpayment amp invoice repeat",
-		test: testSendPaymentAMPInvoiceRepeat,
-	},
-	{
-		name: "send multi path payment",
-		test: testSendMultiPathPayment,
-	},
-	{
-		name: "forward interceptor",
-		test: testForwardInterceptorBasic,
-	},
-	{
-		name: "forward interceptor dedup htlcs",
-		test: testForwardInterceptorDedupHtlc,
-	},
-	{
-		name: "wallet import account",
-		test: testWalletImportAccount,
-	},
-	{
-		name: "wallet import pubkey",
-		test: testWalletImportPubKey,
-	},
-	{
-		name: "remote signer",
-		test: testRemoteSigner,
-	},
-	{
-		name: "taproot",
-		test: testTaproot,
-	},
-	{
-		name: "zero conf channel open",
-		test: testZeroConfChannelOpen,
-	},
-	{
-		name: "option scid alias",
-		test: testOptionScidAlias,
-	},
-	{
-		name: "scid alias channel update",
-		test: testUpdateChannelPolicyScidAlias,
-	},
-	{
-		name: "scid alias upgrade",
-		test: testOptionScidUpgrade,
-	},
-	{
-		name: "nonstd sweep",
-		test: testNonstdSweep,
-	},
-	{
-		name: "taproot coop close",
-		test: testTaprootCoopClose,
-	},
-	{
-		name: "trackpayments",
-		test: testTrackPayments,
-	},
-	{
-		name: "open channel fee policy",
-		test: testOpenChannelUpdateFeePolicy,
-	},
-	{
-		name: "custom messaging",
-		test: testCustomMessage,
-	},
 }

lntest/itest/lnd_trackpayments_test.go

@@ -1,102 +1,89 @@
 package itest
 
 import (
-	"context"
 	"encoding/hex"
+	"time"
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
-	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/lntemp"
 	"github.com/stretchr/testify/require"
 )
 
 // testTrackPayments tests whether a client that calls the TrackPayments api
 // receives payment updates.
-func testTrackPayments(net *lntest.NetworkHarness, t *harnessTest) {
+func testTrackPayments(ht *lntemp.HarnessTest) {
 	// Open a channel between alice and bob.
-	net.EnsureConnected(t.t, net.Alice, net.Bob)
-	channel := openChannelAndAssert(
-		t, net, net.Alice, net.Bob,
-		lntest.OpenChannelParams{
+	alice, bob := ht.Alice, ht.Bob
+	channel := ht.OpenChannel(
+		alice, bob, lntemp.OpenChannelParams{
 			Amt: btcutil.Amount(300000),
 		},
 	)
-	defer closeChannelAndAssert(t, net, net.Alice, channel, true)
-
-	err := net.Alice.WaitForNetworkChannelOpen(channel)
-	require.NoError(t.t, err, "unable to wait for channel to open")
-
-	ctxb := context.Background()
-	ctxt, cancelTracker := context.WithCancel(ctxb)
-	defer cancelTracker()
 
 	// Call the TrackPayments api to listen for payment updates.
-	tracker, err := net.Alice.RouterClient.TrackPayments(
-		ctxt,
-		&routerrpc.TrackPaymentsRequest{
-			NoInflightUpdates: false,
-		},
-	)
-	require.NoError(t.t, err, "failed to call TrackPayments successfully.")
+	req := &routerrpc.TrackPaymentsRequest{
+		NoInflightUpdates: false,
+	}
+	tracker := alice.RPC.TrackPayments(req)
 
 	// Create an invoice from bob.
 	var amountMsat int64 = 1000
-	invoiceResp, err := net.Bob.AddInvoice(
-		ctxb,
+	invoiceResp := bob.RPC.AddInvoice(
 		&lnrpc.Invoice{
 			ValueMsat: amountMsat,
 		},
 	)
-	require.NoError(t.t, err, "unable to add invoice.")
-
-	invoice, err := net.Bob.LookupInvoice(
-		ctxb,
-		&lnrpc.PaymentHash{
-			RHashStr: hex.EncodeToString(invoiceResp.RHash),
-		},
-	)
-	require.NoError(t.t, err, "unable to find invoice.")
+	invoice := bob.RPC.LookupInvoice(invoiceResp.RHash)
 
 	// Send payment from alice to bob.
-	paymentClient, err := net.Alice.RouterClient.SendPaymentV2(
-		ctxb,
+	paymentClient := alice.RPC.SendPayment(
 		&routerrpc.SendPaymentRequest{
 			PaymentRequest: invoice.PaymentRequest,
 			TimeoutSeconds: 60,
 		},
 	)
-	require.NoError(t.t, err, "unable to send payment.")
 
 	// Make sure the payment doesn't error due to invalid parameters or so.
-	_, err = paymentClient.Recv()
-	require.NoError(t.t, err, "unable to get payment update.")
+	_, err := paymentClient.Recv()
+	require.NoError(ht, err, "unable to get payment update.")
 
 	// Assert the first payment update is an inflight update.
 	update1, err := tracker.Recv()
-	require.NoError(t.t, err, "unable to receive payment update 1.")
+	require.NoError(ht, err, "unable to receive payment update 1.")
 
 	require.Equal(
-		t.t, lnrpc.PaymentFailureReason_FAILURE_REASON_NONE,
+		ht, lnrpc.PaymentFailureReason_FAILURE_REASON_NONE,
 		update1.FailureReason,
 	)
-	require.Equal(t.t, lnrpc.Payment_IN_FLIGHT, update1.Status)
-	require.Equal(t.t, invoice.PaymentRequest, update1.PaymentRequest)
-	require.Equal(t.t, amountMsat, update1.ValueMsat)
+	require.Equal(ht, lnrpc.Payment_IN_FLIGHT, update1.Status)
+	require.Equal(ht, invoice.PaymentRequest, update1.PaymentRequest)
+	require.Equal(ht, amountMsat, update1.ValueMsat)
 
 	// Assert the second payment update is a payment success update.
 	update2, err := tracker.Recv()
-	require.NoError(t.t, err, "unable to receive payment update 2.")
+	require.NoError(ht, err, "unable to receive payment update 2.")
 
 	require.Equal(
-		t.t, lnrpc.PaymentFailureReason_FAILURE_REASON_NONE,
+		ht, lnrpc.PaymentFailureReason_FAILURE_REASON_NONE,
 		update2.FailureReason,
 	)
-	require.Equal(t.t, lnrpc.Payment_SUCCEEDED, update2.Status)
-	require.Equal(t.t, invoice.PaymentRequest, update2.PaymentRequest)
-	require.Equal(t.t, amountMsat, update2.ValueMsat)
+	require.Equal(ht, lnrpc.Payment_SUCCEEDED, update2.Status)
+	require.Equal(ht, invoice.PaymentRequest, update2.PaymentRequest)
+	require.Equal(ht, amountMsat, update2.ValueMsat)
 	require.Equal(
-		t.t, hex.EncodeToString(invoice.RPreimage),
+		ht, hex.EncodeToString(invoice.RPreimage),
 		update2.PaymentPreimage,
 	)
+
+	// TODO(yy): remove the sleep once the following bug is fixed.
+	// When the invoice is reported settled, the commitment dance is not
+	// yet finished, which can cause an error when closing the channel,
+	// saying there's active HTLCs. We need to investigate this issue and
+	// reverse the order to, first finish the commitment dance, then report
+	// the invoice as settled.
+	time.Sleep(2 * time.Second)
+
+	ht.CloseChannel(alice, channel)
 }

lntest/itest/lnd_wallet_import_test.go

@@ -2,10 +2,6 @@ package itest
 
 import (
 	"bytes"
-	"context"
-	"crypto/rand"
-	"fmt"
-	"math"
 	"testing"
 	"time"
 
@@ -20,8 +16,8 @@ import (
 	"github.com/lightningnetwork/lnd/funding"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
-	"github.com/lightningnetwork/lnd/lntest"
-	"github.com/lightningnetwork/lnd/lntest/wait"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/lightningnetwork/lnd/lntemp/node"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/stretchr/testify/require"
 )
@@ -55,30 +51,27 @@ func walletToLNAddrType(t *testing.T,
 
 // newExternalAddr generates a new external address of an imported account for a
 // pair of nodes, where one acts as the funder and the other as the signer.
-func newExternalAddr(t *testing.T, funder, signer *lntest.HarnessNode,
+func newExternalAddr(ht *lntemp.HarnessTest, funder, signer *node.HarnessNode,
 	importedAccount string, addrType walletrpc.AddressType) string {
 
 	// We'll generate a new address for Carol from Dave's node to receive
 	// and fund a new channel.
-	ctxb := context.Background()
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	funderResp, err := funder.NewAddress(ctxt, &lnrpc.NewAddressRequest{
-		Type:    walletToLNAddrType(t, addrType),
+	req := &lnrpc.NewAddressRequest{
+		Type:    walletToLNAddrType(ht.T, addrType),
 		Account: importedAccount,
-	})
-	require.NoError(t, err)
+	}
+	funderResp := funder.RPC.NewAddress(req)
 
-	// Carol also needs to generate the address for the sake of this test to
-	// be able to sign the channel funding input.
-	signerResp, err := signer.NewAddress(ctxt, &lnrpc.NewAddressRequest{
-		Type: walletToLNAddrType(t, addrType),
-	})
-	require.NoError(t, err)
+	// Carol also needs to generate the address for the sake of this test
+	// to be able to sign the channel funding input.
+	req = &lnrpc.NewAddressRequest{
+		Type: walletToLNAddrType(ht.T, addrType),
+	}
+	signerResp := signer.RPC.NewAddress(req)
 
 	// Sanity check that the generated addresses match.
-	require.Equal(t, funderResp.Address, signerResp.Address)
-	assertExternalAddrType(t, funderResp.Address, addrType)
+	require.Equal(ht, funderResp.Address, signerResp.Address)
+	assertExternalAddrType(ht.T, funderResp.Address, addrType)
 
 	return funderResp.Address
 }
@@ -130,108 +123,21 @@ func assertOutputScriptType(t *testing.T, expType txscript.ScriptClass,
 		spew.Sdump(tx))
 }
 
-// assertAccountBalance asserts that the unconfirmed and confirmed balance for
-// the given account is satisfied by the WalletBalance and ListUnspent RPCs. The
-// unconfirmed balance is not checked for neutrino nodes.
-func assertAccountBalance(t *testing.T, node *lntest.HarnessNode, account string,
-	confirmedBalance, unconfirmedBalance int64) {
-
-	err := wait.NoError(func() error {
-		balanceResp, err := node.WalletBalance(
-			context.Background(), &lnrpc.WalletBalanceRequest{},
-		)
-		if err != nil {
-			return err
-		}
-		require.Contains(t, balanceResp.AccountBalance, account)
-		accountBalance := balanceResp.AccountBalance[account]
-
-		// Check confirmed balance.
-		if accountBalance.ConfirmedBalance != confirmedBalance {
-			return fmt.Errorf("expected confirmed balance %v, "+
-				"got %v", confirmedBalance,
-				accountBalance.ConfirmedBalance)
-		}
-		listUtxosReq := &lnrpc.ListUnspentRequest{
-			MinConfs: 1,
-			MaxConfs: math.MaxInt32,
-			Account:  account,
-		}
-		confirmedUtxosResp, err := node.ListUnspent(
-			context.Background(), listUtxosReq,
-		)
-		if err != nil {
-			return err
-		}
-		var totalConfirmedVal int64
-		for _, utxo := range confirmedUtxosResp.Utxos {
-			totalConfirmedVal += utxo.AmountSat
-		}
-		if totalConfirmedVal != confirmedBalance {
-			return fmt.Errorf("expected total confirmed utxo "+
-				"balance %v, got %v", confirmedBalance,
-				totalConfirmedVal)
-		}
-
-		// Skip unconfirmed balance checks for neutrino nodes.
-		if node.Cfg.BackendCfg.Name() == lntest.NeutrinoBackendName {
-			return nil
-		}
-
-		// Check unconfirmed balance.
-		if accountBalance.UnconfirmedBalance != unconfirmedBalance {
-			return fmt.Errorf("expected unconfirmed balance %v, "+
-				"got %v", unconfirmedBalance,
-				accountBalance.UnconfirmedBalance)
-		}
-		listUtxosReq.MinConfs = 0
-		listUtxosReq.MaxConfs = 0
-		unconfirmedUtxosResp, err := node.ListUnspent(
-			context.Background(), listUtxosReq,
-		)
-		require.NoError(t, err)
-		var totalUnconfirmedVal int64
-		for _, utxo := range unconfirmedUtxosResp.Utxos {
-			totalUnconfirmedVal += utxo.AmountSat
-		}
-		if totalUnconfirmedVal != unconfirmedBalance {
-			return fmt.Errorf("expected total unconfirmed utxo "+
-				"balance %v, got %v", unconfirmedBalance,
-				totalUnconfirmedVal)
-		}
-
-		return nil
-	}, defaultTimeout)
-	require.NoError(t, err)
-}
-
 // psbtSendFromImportedAccount attempts to fund a PSBT from the given imported
 // account, originating from the source node to the destination.
-func psbtSendFromImportedAccount(t *harnessTest, srcNode, destNode,
-	signer *lntest.HarnessNode, account string,
+func psbtSendFromImportedAccount(ht *lntemp.HarnessTest, srcNode, destNode,
+	signer *node.HarnessNode, account string,
 	accountAddrType walletrpc.AddressType) {
 
-	ctxb := context.Background()
-
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	balanceResp, err := srcNode.WalletBalance(
-		ctxt, &lnrpc.WalletBalanceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Contains(t.t, balanceResp.AccountBalance, account)
+	balanceResp := srcNode.RPC.WalletBalance()
+	require.Contains(ht, balanceResp.AccountBalance, account)
 	confBalance := balanceResp.AccountBalance[account].ConfirmedBalance
 
 	destAmt := confBalance - 10000
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	destAddrResp, err := destNode.NewAddress(ctxt, &lnrpc.NewAddressRequest{
+	destAddrResp := destNode.RPC.NewAddress(&lnrpc.NewAddressRequest{
 		Type: lnrpc.AddressType_WITNESS_PUBKEY_HASH,
 	})
-	require.NoError(t.t, err)
 
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	fundReq := &walletrpc.FundPsbtRequest{
 		Template: &walletrpc.FundPsbtRequest_Raw{
 			Raw: &walletrpc.TxTemplate{
@@ -245,29 +151,20 @@ func psbtSendFromImportedAccount(t *harnessTest, srcNode, destNode,
 		},
 		Account: account,
 	}
-	fundResp, err := srcNode.WalletKitClient.FundPsbt(ctxt, fundReq)
-	require.NoError(t.t, err)
+	fundResp := srcNode.RPC.FundPsbt(fundReq)
 
 	// Have Carol sign the PSBT input since Dave doesn't have any private
 	// key information.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	finalizeReq := &walletrpc.FinalizePsbtRequest{
 		FundedPsbt: fundResp.FundedPsbt,
 	}
-	finalizeResp, err := signer.WalletKitClient.FinalizePsbt(
-		ctxt, finalizeReq,
-	)
-	require.NoError(t.t, err)
+	finalizeResp := signer.RPC.FinalizePsbt(finalizeReq)
 
 	// With the PSBT signed, we can broadcast the resulting transaction.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	publishReq := &walletrpc.Transaction{
 		TxHex: finalizeResp.RawFinalTx,
 	}
-	_, err = srcNode.WalletKitClient.PublishTransaction(ctxt, publishReq)
-	require.NoError(t.t, err)
+	srcNode.RPC.PublishTransaction(publishReq)
 
 	// Carol's balance from Dave's perspective should update accordingly.
 	var (
@@ -304,7 +201,7 @@ func psbtSendFromImportedAccount(t *harnessTest, srcNode, destNode,
 		expChangeScriptType = txscript.WitnessV1TaprootTy
 
 	default:
-		t.Fatalf("unsupported addr type %v", accountAddrType)
+		ht.Fatalf("unsupported addr type %v", accountAddrType)
 	}
 	changeUtxoAmt := confBalance - destAmt - expTxFee
 
@@ -314,16 +211,20 @@ func psbtSendFromImportedAccount(t *harnessTest, srcNode, destNode,
 	if account == defaultImportedAccount {
 		accountWithBalance = defaultAccount
 	}
-	assertAccountBalance(t.t, srcNode, accountWithBalance, 0, changeUtxoAmt)
-	_ = mineBlocks(t, t.lndHarness, 1, 1)
-	assertAccountBalance(t.t, srcNode, accountWithBalance, changeUtxoAmt, 0)
+	ht.AssertWalletAccountBalance(
+		srcNode, accountWithBalance, 0, changeUtxoAmt,
+	)
+	ht.MineBlocksAndAssertNumTxes(1, 1)
+	ht.AssertWalletAccountBalance(
+		srcNode, accountWithBalance, changeUtxoAmt, 0,
+	)
 
 	// Finally, assert that the transaction has the expected change address
 	// type based on the account.
 	var tx wire.MsgTx
-	err = tx.Deserialize(bytes.NewReader(finalizeResp.RawFinalTx))
-	require.NoError(t.t, err)
-	assertOutputScriptType(t.t, expChangeScriptType, &tx, changeUtxoAmt)
+	err := tx.Deserialize(bytes.NewReader(finalizeResp.RawFinalTx))
+	require.NoError(ht, err)
+	assertOutputScriptType(ht.T, expChangeScriptType, &tx, changeUtxoAmt)
 }
 
 // fundChanAndCloseFromImportedAccount attempts to a fund a channel from the
@@ -331,21 +232,14 @@ func psbtSendFromImportedAccount(t *harnessTest, srcNode, destNode,
 // node. To ensure the channel is operational before closing it, a test payment
 // is made. Several balance assertions are made along the way for the sake of
 // correctness.
-func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
-	signer *lntest.HarnessNode, account string,
+func fundChanAndCloseFromImportedAccount(ht *lntemp.HarnessTest, srcNode,
+	destNode, signer *node.HarnessNode, account string,
 	accountAddrType walletrpc.AddressType, utxoAmt, chanSize int64) {
 
-	ctxb := context.Background()
-
 	// Retrieve the current confirmed balance to make some assertions later
 	// on.
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	balanceResp, err := srcNode.WalletBalance(
-		ctxt, &lnrpc.WalletBalanceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Contains(t.t, balanceResp.AccountBalance, account)
+	balanceResp := srcNode.RPC.WalletBalance()
+	require.Contains(ht, balanceResp.AccountBalance, account)
 	accountConfBalance := balanceResp.
 		AccountBalance[account].ConfirmedBalance
 	defaultAccountConfBalance := balanceResp.
@@ -353,31 +247,23 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 
 	// Now, start the channel funding process. We'll need to connect both
 	// nodes first.
-	t.lndHarness.EnsureConnected(t.t, srcNode, destNode)
+	ht.EnsureConnected(srcNode, destNode)
 
 	// The source node will then fund the channel through a PSBT shim.
-	var pendingChanID [32]byte
-	_, err = rand.Read(pendingChanID[:])
-	require.NoError(t.t, err)
-
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	chanUpdates, rawPsbt, err := openChannelPsbt(
-		ctxt, srcNode, destNode, lntest.OpenChannelParams{
+	pendingChanID := ht.Random32Bytes()
+	chanUpdates, rawPsbt := ht.OpenChannelPsbt(
+		srcNode, destNode, lntemp.OpenChannelParams{
 			Amt: btcutil.Amount(chanSize),
 			FundingShim: &lnrpc.FundingShim{
 				Shim: &lnrpc.FundingShim_PsbtShim{
 					PsbtShim: &lnrpc.PsbtShim{
-						PendingChanId: pendingChanID[:],
+						PendingChanId: pendingChanID,
 					},
 				},
 			},
 		},
 	)
-	require.NoError(t.t, err)
 
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	fundReq := &walletrpc.FundPsbtRequest{
 		Template: &walletrpc.FundPsbtRequest_Psbt{
 			Psbt: rawPsbt,
@@ -387,49 +273,40 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 		},
 		Account: account,
 	}
-	fundResp, err := srcNode.WalletKitClient.FundPsbt(ctxt, fundReq)
-	require.NoError(t.t, err)
+	fundResp := srcNode.RPC.FundPsbt(fundReq)
 
-	_, err = srcNode.FundingStateStep(ctxb, &lnrpc.FundingTransitionMsg{
+	srcNode.RPC.FundingStateStep(&lnrpc.FundingTransitionMsg{
 		Trigger: &lnrpc.FundingTransitionMsg_PsbtVerify{
 			PsbtVerify: &lnrpc.FundingPsbtVerify{
-				PendingChanId: pendingChanID[:],
+				PendingChanId: pendingChanID,
 				FundedPsbt:    fundResp.FundedPsbt,
 			},
 		},
 	})
-	require.NoError(t.t, err)
 
 	// Now that we have a PSBT to fund the channel, our signer needs to sign
 	// it.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	finalizeReq := &walletrpc.FinalizePsbtRequest{
 		FundedPsbt: fundResp.FundedPsbt,
 	}
-	finalizeResp, err := signer.WalletKitClient.FinalizePsbt(ctxt, finalizeReq)
-	require.NoError(t.t, err)
+	finalizeResp := signer.RPC.FinalizePsbt(finalizeReq)
 
 	// The source node can then submit the signed PSBT and complete the
 	// channel funding process.
-	_, err = srcNode.FundingStateStep(ctxb, &lnrpc.FundingTransitionMsg{
+	srcNode.RPC.FundingStateStep(&lnrpc.FundingTransitionMsg{
 		Trigger: &lnrpc.FundingTransitionMsg_PsbtFinalize{
 			PsbtFinalize: &lnrpc.FundingPsbtFinalize{
-				PendingChanId: pendingChanID[:],
+				PendingChanId: pendingChanID,
 				SignedPsbt:    finalizeResp.SignedPsbt,
 			},
 		},
 	})
-	require.NoError(t.t, err)
 
 	// We should receive a notification of the channel funding transaction
 	// being broadcast.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	updateResp, err := receiveChanUpdate(ctxt, chanUpdates)
-	require.NoError(t.t, err)
+	updateResp := ht.ReceiveOpenChannelUpdate(chanUpdates)
 	upd, ok := updateResp.Update.(*lnrpc.OpenStatusUpdate_ChanPending)
-	require.True(t.t, ok)
+	require.True(ht, ok)
 
 	// Mine enough blocks to announce the channel to the network, making
 	// balance assertions along the way.
@@ -467,11 +344,11 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 		expChangeScriptType = txscript.WitnessV1TaprootTy
 
 	default:
-		t.Fatalf("unsupported addr type %v", accountAddrType)
+		ht.Fatalf("unsupported addr type %v", accountAddrType)
 	}
 	chanChangeUtxoAmt := utxoAmt - chanSize - expChanTxFee
 	txHash, err := chainhash.NewHash(upd.ChanPending.Txid)
-	require.NoError(t.t, err)
+	require.NoError(ht, err)
 
 	// If we're spending from the default imported account, then any change
 	// outputs produced are moved to the default wallet account, so we
@@ -479,35 +356,35 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 	var confBalanceAfterChan int64
 	if account == defaultImportedAccount {
 		confBalanceAfterChan = defaultAccountConfBalance
-		assertAccountBalance(t.t, srcNode, account, 0, 0)
-		assertAccountBalance(
-			t.t, srcNode, defaultAccount, defaultAccountConfBalance,
+		ht.AssertWalletAccountBalance(srcNode, account, 0, 0)
+		ht.AssertWalletAccountBalance(
+			srcNode, defaultAccount, defaultAccountConfBalance,
 			chanChangeUtxoAmt,
 		)
 
-		block := mineBlocks(t, t.lndHarness, 6, 1)[0]
-		assertTxInBlock(t, block, txHash)
+		block := ht.MineBlocksAndAssertNumTxes(6, 1)[0]
+		ht.Miner.AssertTxInBlock(block, txHash)
 
 		confBalanceAfterChan += chanChangeUtxoAmt
-		assertAccountBalance(t.t, srcNode, account, 0, 0)
-		assertAccountBalance(
-			t.t, srcNode, defaultAccount, confBalanceAfterChan, 0,
+		ht.AssertWalletAccountBalance(srcNode, account, 0, 0)
+		ht.AssertWalletAccountBalance(
+			srcNode, defaultAccount, confBalanceAfterChan, 0,
 		)
 	} else {
 		// Otherwise, all interactions remain within Carol's imported
 		// account.
 		confBalanceAfterChan = accountConfBalance - utxoAmt
-		assertAccountBalance(
-			t.t, srcNode, account, confBalanceAfterChan,
+		ht.AssertWalletAccountBalance(
+			srcNode, account, confBalanceAfterChan,
 			chanChangeUtxoAmt,
 		)
 
-		block := mineBlocks(t, t.lndHarness, 6, 1)[0]
-		assertTxInBlock(t, block, txHash)
+		block := ht.MineBlocksAndAssertNumTxes(6, 1)[0]
+		ht.Miner.AssertTxInBlock(block, txHash)
 
 		confBalanceAfterChan += chanChangeUtxoAmt
-		assertAccountBalance(
-			t.t, srcNode, account, confBalanceAfterChan, 0,
+		ht.AssertWalletAccountBalance(
+			srcNode, account, confBalanceAfterChan, 0,
 		)
 	}
 
@@ -515,8 +392,10 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 	// based on the account.
 	var tx wire.MsgTx
 	err = tx.Deserialize(bytes.NewReader(finalizeResp.RawFinalTx))
-	require.NoError(t.t, err)
-	assertOutputScriptType(t.t, expChangeScriptType, &tx, chanChangeUtxoAmt)
+	require.NoError(ht, err)
+	assertOutputScriptType(
+		ht.T, expChangeScriptType, &tx, chanChangeUtxoAmt,
+	)
 
 	// Wait for the channel to be announced by both parties.
 	chanPoint := &lnrpc.ChannelPoint{
@@ -525,29 +404,30 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 		},
 		OutputIndex: upd.ChanPending.OutputIndex,
 	}
-	err = srcNode.WaitForNetworkChannelOpen(chanPoint)
-	require.NoError(t.t, err)
-	err = destNode.WaitForNetworkChannelOpen(chanPoint)
-	require.NoError(t.t, err)
+	ht.AssertTopologyChannelOpen(srcNode, chanPoint)
+	ht.AssertTopologyChannelOpen(destNode, chanPoint)
 
 	// Send a test payment to ensure the channel is operating as normal.
 	const invoiceAmt = 100000
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	resp, err := destNode.AddInvoice(ctxt, &lnrpc.Invoice{
+	invoice := &lnrpc.Invoice{
 		Memo:  "psbt import chan",
 		Value: invoiceAmt,
-	})
-	require.NoError(t.t, err)
+	}
+	resp := destNode.RPC.AddInvoice(invoice)
 
-	err = completePaymentRequests(
-		srcNode, srcNode.RouterClient,
-		[]string{resp.PaymentRequest}, true,
-	)
-	require.NoError(t.t, err)
+	ht.CompletePaymentRequests(srcNode, []string{resp.PaymentRequest})
+
+	// TODO(yy): remove the sleep once the following bug is fixed. When the
+	// payment is reported as settled by srcNode, it's expected the
+	// commitment dance is finished and all subsequent states have been
+	// updated. Yet we'd receive the error `cannot co-op close channel with
+	// active htlcs` or `link failed to shutdown` if we close the channel.
+	// We need to investigate the order of settling the payments and
+	// updating commitments to understand and fix .
+	time.Sleep(2 * time.Second)
 
 	// Now that we've confirmed the opened channel works, we'll close it.
-	closeChannelAndAssert(t, t.lndHarness, srcNode, chanPoint, false)
+	ht.CloseChannel(srcNode, chanPoint)
 
 	// Since the channel still had funds left on the source node's side,
 	// they must've been redeemed after the close. Without a pre-negotiated
@@ -557,17 +437,17 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 	balanceFromClosedChan := chanSize - invoiceAmt - chanCloseTxFee
 
 	if account == defaultImportedAccount {
-		assertAccountBalance(t.t, srcNode, account, 0, 0)
-		assertAccountBalance(
-			t.t, srcNode, defaultAccount,
+		ht.AssertWalletAccountBalance(srcNode, account, 0, 0)
+		ht.AssertWalletAccountBalance(
+			srcNode, defaultAccount,
 			confBalanceAfterChan+balanceFromClosedChan, 0,
 		)
 	} else {
-		assertAccountBalance(
-			t.t, srcNode, account, confBalanceAfterChan, 0,
+		ht.AssertWalletAccountBalance(
+			srcNode, account, confBalanceAfterChan, 0,
 		)
-		assertAccountBalance(
-			t.t, srcNode, defaultAccount, balanceFromClosedChan, 0,
+		ht.AssertWalletAccountBalance(
+			srcNode, defaultAccount, balanceFromClosedChan, 0,
 		)
 	}
 }
@@ -575,18 +455,20 @@ func fundChanAndCloseFromImportedAccount(t *harnessTest, srcNode, destNode,
 // testWalletImportAccount tests that an imported account can fund transactions
 // and channels through PSBTs, by having one node (the one with the imported
 // account) craft the transactions and another node act as the signer.
-func testWalletImportAccount(net *lntest.NetworkHarness, t *harnessTest) {
+func testWalletImportAccount(ht *lntemp.HarnessTest) {
 	testCases := []struct {
 		name     string
 		addrType walletrpc.AddressType
 	}{
 		{
-			name:     "standard BIP-0049",
-			addrType: walletrpc.AddressType_NESTED_WITNESS_PUBKEY_HASH,
+			name: "standard BIP-0049",
+			addrType: walletrpc.
+				AddressType_NESTED_WITNESS_PUBKEY_HASH,
 		},
 		{
-			name:     "lnd BIP-0049 variant",
-			addrType: walletrpc.AddressType_HYBRID_NESTED_WITNESS_PUBKEY_HASH,
+			name: "lnd BIP-0049 variant",
+			addrType: walletrpc.
+				AddressType_HYBRID_NESTED_WITNESS_PUBKEY_HASH,
 		},
 		{
 			name:     "standard BIP-0084",
@@ -600,23 +482,24 @@ func testWalletImportAccount(net *lntest.NetworkHarness, t *harnessTest) {
 
 	for _, tc := range testCases {
 		tc := tc
-		success := t.t.Run(tc.name, func(tt *testing.T) {
-			ht := newHarnessTest(tt, net)
-			ht.RunTestCase(&testCase{
-				name: tc.name,
-				test: func(net1 *lntest.NetworkHarness,
-					t1 *harnessTest) {
+		success := ht.Run(tc.name, func(tt *testing.T) {
+			testFunc := func(ht *lntemp.HarnessTest) {
+				testWalletImportAccountScenario(
+					ht, tc.addrType,
+				)
+			}
 
-					testWalletImportAccountScenario(
-						net, t, tc.addrType,
-					)
-				},
+			st := ht.Subtest(tt)
+
+			st.RunTestCase(&lntemp.TestCase{
+				Name:     tc.name,
+				TestFunc: testFunc,
 			})
 		})
 		if !success {
 			// Log failure time to help relate the lnd logs to the
 			// failure.
-			t.Logf("Failure time: %v", time.Now().Format(
+			ht.Logf("Failure time: %v", time.Now().Format(
 				"2006-01-02 15:04:05.000",
 			))
 			break
@@ -624,115 +507,103 @@ func testWalletImportAccount(net *lntest.NetworkHarness, t *harnessTest) {
 	}
 }
 
-func testWalletImportAccountScenario(net *lntest.NetworkHarness, t *harnessTest,
+func testWalletImportAccountScenario(ht *lntemp.HarnessTest,
 	addrType walletrpc.AddressType) {
 
 	// We'll start our test by having two nodes, Carol and Dave. Carol's
 	// default wallet account will be imported into Dave's node.
-	carol := net.NewNode(t.t, "carol", nil)
-	defer shutdownAndAssert(net, t, carol)
+	//
+	// NOTE: we won't use standby nodes here since the test will change
+	// each of the node's wallet state.
+	carol := ht.NewNode("carol", nil)
+	dave := ht.NewNode("dave", nil)
 
-	dave := net.NewNode(t.t, "dave", nil)
-	defer shutdownAndAssert(net, t, dave)
-
-	runWalletImportAccountScenario(net, t, addrType, carol, dave)
+	runWalletImportAccountScenario(ht, addrType, carol, dave)
 }
 
-func runWalletImportAccountScenario(net *lntest.NetworkHarness, t *harnessTest,
-	addrType walletrpc.AddressType, carol, dave *lntest.HarnessNode) {
+func runWalletImportAccountScenario(ht *lntemp.HarnessTest,
+	addrType walletrpc.AddressType, carol, dave *node.HarnessNode) {
 
-	ctxb := context.Background()
 	const utxoAmt int64 = btcutil.SatoshiPerBitcoin
 
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	listReq := &walletrpc.ListAccountsRequest{
 		Name:        "default",
 		AddressType: addrType,
 	}
-	listResp, err := carol.WalletKitClient.ListAccounts(ctxt, listReq)
-	require.NoError(t.t, err)
-	require.Equal(t.t, len(listResp.Accounts), 1)
+	listResp := carol.RPC.ListAccounts(listReq)
+	require.Len(ht, listResp.Accounts, 1)
 	carolAccount := listResp.Accounts[0]
 
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
 	const importedAccount = "carol"
 	importReq := &walletrpc.ImportAccountRequest{
 		Name:              importedAccount,
 		ExtendedPublicKey: carolAccount.ExtendedPublicKey,
 		AddressType:       addrType,
 	}
-	_, err = dave.WalletKitClient.ImportAccount(ctxt, importReq)
-	require.NoError(t.t, err)
+	dave.RPC.ImportAccount(importReq)
 
 	// We'll generate an address for Carol from Dave's node to receive some
 	// funds.
 	externalAddr := newExternalAddr(
-		t.t, dave, carol, importedAccount, addrType,
+		ht, dave, carol, importedAccount, addrType,
 	)
 
 	// Send coins to Carol's address and confirm them, making sure the
 	// balance updates accordingly.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	_, err = net.Alice.SendCoins(ctxt, &lnrpc.SendCoinsRequest{
+	alice := ht.Alice
+	req := &lnrpc.SendCoinsRequest{
 		Addr:       externalAddr,
 		Amount:     utxoAmt,
 		SatPerByte: 1,
-	})
-	require.NoError(t.t, err)
+	}
+	alice.RPC.SendCoins(req)
 
-	assertAccountBalance(t.t, dave, importedAccount, 0, utxoAmt)
-	_ = mineBlocks(t, net, 1, 1)
-	assertAccountBalance(t.t, dave, importedAccount, utxoAmt, 0)
+	ht.AssertWalletAccountBalance(dave, importedAccount, 0, utxoAmt)
+	ht.MineBlocksAndAssertNumTxes(1, 1)
+	ht.AssertWalletAccountBalance(dave, importedAccount, utxoAmt, 0)
 
 	// To ensure that Dave can use Carol's account as watch-only, we'll
 	// construct a PSBT that sends funds to Alice, which we'll then hand
 	// over to Carol to sign.
 	psbtSendFromImportedAccount(
-		t, dave, net.Alice, carol, importedAccount, addrType,
+		ht, dave, alice, carol, importedAccount, addrType,
 	)
 
 	// We'll generate a new address for Carol from Dave's node to receive
 	// and fund a new channel.
 	externalAddr = newExternalAddr(
-		t.t, dave, carol, importedAccount, addrType,
+		ht, dave, carol, importedAccount, addrType,
 	)
 
 	// Retrieve the current confirmed balance of the imported account for
 	// some assertions we'll make later on.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	balanceResp, err := dave.WalletBalance(
-		ctxt, &lnrpc.WalletBalanceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Contains(t.t, balanceResp.AccountBalance, importedAccount)
-	confBalance := balanceResp.AccountBalance[importedAccount].ConfirmedBalance
+	balanceResp := dave.RPC.WalletBalance()
+	require.Contains(ht, balanceResp.AccountBalance, importedAccount)
+	confBalance := balanceResp.AccountBalance[importedAccount].
+		ConfirmedBalance
 
 	// Send coins to Carol's address and confirm them, making sure the
 	// balance updates accordingly.
-	ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	_, err = net.Alice.SendCoins(ctxt, &lnrpc.SendCoinsRequest{
+	req = &lnrpc.SendCoinsRequest{
 		Addr:       externalAddr,
 		Amount:     utxoAmt,
 		SatPerByte: 1,
-	})
-	require.NoError(t.t, err)
+	}
+	alice.RPC.SendCoins(req)
 
-	assertAccountBalance(t.t, dave, importedAccount, confBalance, utxoAmt)
-	_ = mineBlocks(t, net, 1, 1)
-	assertAccountBalance(
-		t.t, dave, importedAccount, confBalance+utxoAmt, 0,
+	ht.AssertWalletAccountBalance(
+		dave, importedAccount, confBalance, utxoAmt,
+	)
+	ht.MineBlocksAndAssertNumTxes(1, 1)
+	ht.AssertWalletAccountBalance(
+		dave, importedAccount, confBalance+utxoAmt, 0,
 	)
 
 	// Now that we have enough funds, it's time to fund the channel, make a
 	// test payment, and close it. This contains several balance assertions
 	// along the way.
 	fundChanAndCloseFromImportedAccount(
-		t, dave, net.Alice, carol, importedAccount, addrType, utxoAmt,
+		ht, dave, alice, carol, importedAccount, addrType, utxoAmt,
 		int64(funding.MaxBtcFundingAmount),
 	)
 }
@@ -740,14 +611,15 @@ func runWalletImportAccountScenario(net *lntest.NetworkHarness, t *harnessTest,
 // testWalletImportPubKey tests that an imported public keys can fund
 // transactions and channels through PSBTs, by having one node (the one with the
 // imported account) craft the transactions and another node act as the signer.
-func testWalletImportPubKey(net *lntest.NetworkHarness, t *harnessTest) {
+func testWalletImportPubKey(ht *lntemp.HarnessTest) {
 	testCases := []struct {
 		name     string
 		addrType walletrpc.AddressType
 	}{
 		{
-			name:     "BIP-0049",
-			addrType: walletrpc.AddressType_NESTED_WITNESS_PUBKEY_HASH,
+			name: "BIP-0049",
+			addrType: walletrpc.
+				AddressType_NESTED_WITNESS_PUBKEY_HASH,
 		},
 		{
 			name:     "BIP-0084",
@@ -761,23 +633,24 @@ func testWalletImportPubKey(net *lntest.NetworkHarness, t *harnessTest) {
 
 	for _, tc := range testCases {
 		tc := tc
-		success := t.t.Run(tc.name, func(tt *testing.T) {
-			ht := newHarnessTest(tt, net)
-			ht.RunTestCase(&testCase{
-				name: tc.name,
-				test: func(net1 *lntest.NetworkHarness,
-					t1 *harnessTest) {
+		success := ht.Run(tc.name, func(tt *testing.T) {
+			testFunc := func(ht *lntemp.HarnessTest) {
+				testWalletImportPubKeyScenario(
+					ht, tc.addrType,
+				)
+			}
 
-					testWalletImportPubKeyScenario(
-						net, t, tc.addrType,
-					)
-				},
+			st := ht.Subtest(tt)
+
+			st.RunTestCase(&lntemp.TestCase{
+				Name:     tc.name,
+				TestFunc: testFunc,
 			})
 		})
 		if !success {
 			// Log failure time to help relate the lnd logs to the
 			// failure.
-			t.Logf("Failure time: %v", time.Now().Format(
+			ht.Logf("Failure time: %v", time.Now().Format(
 				"2006-01-02 15:04:05.000",
 			))
 			break
@@ -785,18 +658,18 @@ func testWalletImportPubKey(net *lntest.NetworkHarness, t *harnessTest) {
 	}
 }
 
-func testWalletImportPubKeyScenario(net *lntest.NetworkHarness, t *harnessTest,
+func testWalletImportPubKeyScenario(ht *lntemp.HarnessTest,
 	addrType walletrpc.AddressType) {
 
-	ctxb := context.Background()
 	const utxoAmt int64 = btcutil.SatoshiPerBitcoin
+	alice := ht.Alice
 
 	// We'll start our test by having two nodes, Carol and Dave.
-	carol := net.NewNode(t.t, "carol", nil)
-	defer shutdownAndAssert(net, t, carol)
-
-	dave := net.NewNode(t.t, "dave", nil)
-	defer shutdownAndAssert(net, t, dave)
+	//
+	// NOTE: we won't use standby nodes here since the test will change
+	// each of the node's wallet state.
+	carol := ht.NewNode("carol", nil)
+	dave := ht.NewNode("dave", nil)
 
 	// We'll define a helper closure that we'll use throughout the test to
 	// generate a new address of the given type from Carol's perspective,
@@ -806,30 +679,27 @@ func testWalletImportPubKeyScenario(net *lntest.NetworkHarness, t *harnessTest,
 
 		// Retrieve Carol's account public key for the corresponding
 		// address type.
-		ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-		defer cancel()
 		listReq := &walletrpc.ListAccountsRequest{
 			Name:        "default",
 			AddressType: addrType,
 		}
-		listResp, err := carol.WalletKitClient.ListAccounts(
-			ctxt, listReq,
-		)
-		require.NoError(t.t, err)
-		require.Equal(t.t, len(listResp.Accounts), 1)
+		listResp := carol.RPC.ListAccounts(listReq)
+		require.Len(ht, listResp.Accounts, 1)
 		p2wkhAccount := listResp.Accounts[0]
 
 		// Derive the external address at the given index.
 		accountPubKey, err := hdkeychain.NewKeyFromString(
 			p2wkhAccount.ExtendedPublicKey,
 		)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 		externalAccountExtKey, err := accountPubKey.Derive(0)
-		require.NoError(t.t, err)
-		externalAddrExtKey, err := externalAccountExtKey.Derive(keyIndex)
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
+		externalAddrExtKey, err := externalAccountExtKey.Derive(
+			keyIndex,
+		)
+		require.NoError(ht, err)
 		externalAddrPubKey, err := externalAddrExtKey.ECPubKey()
-		require.NoError(t.t, err)
+		require.NoError(ht, err)
 
 		// Serialize as 32-byte x-only pubkey for Taproot addresses.
 		serializedPubKey := externalAddrPubKey.SerializeCompressed()
@@ -840,44 +710,34 @@ func testWalletImportPubKeyScenario(net *lntest.NetworkHarness, t *harnessTest,
 		}
 
 		// Import the public key into Dave.
-		ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-		defer cancel()
 		importReq := &walletrpc.ImportPublicKeyRequest{
 			PublicKey:   serializedPubKey,
 			AddressType: addrType,
 		}
-		_, err = dave.WalletKitClient.ImportPublicKey(ctxt, importReq)
-		require.NoError(t.t, err)
+		dave.RPC.ImportPublicKey(importReq)
 
 		// We'll also generate the same address for Carol, as it'll be
 		// required later when signing.
-		ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-		defer cancel()
-		carolAddrResp, err := carol.NewAddress(
-			ctxt, &lnrpc.NewAddressRequest{
-				Type: walletToLNAddrType(t.t, addrType),
-			},
-		)
-		require.NoError(t.t, err)
+		carolAddrResp := carol.RPC.NewAddress(&lnrpc.NewAddressRequest{
+			Type: walletToLNAddrType(ht.T, addrType),
+		})
 
 		// Send coins to Carol's address and confirm them, making sure
 		// the balance updates accordingly.
-		ctxt, cancel = context.WithTimeout(ctxb, defaultTimeout)
-		defer cancel()
-		_, err = net.Alice.SendCoins(ctxt, &lnrpc.SendCoinsRequest{
+		req := &lnrpc.SendCoinsRequest{
 			Addr:       carolAddrResp.Address,
 			Amount:     utxoAmt,
 			SatPerByte: 1,
-		})
-		require.NoError(t.t, err)
+		}
+		alice.RPC.SendCoins(req)
 
-		assertAccountBalance(
-			t.t, dave, defaultImportedAccount, prevConfBalance,
+		ht.AssertWalletAccountBalance(
+			dave, defaultImportedAccount, prevConfBalance,
 			prevUnconfBalance+utxoAmt,
 		)
-		_ = mineBlocks(t, net, 1, 1)
-		assertAccountBalance(
-			t.t, dave, defaultImportedAccount,
+		ht.MineBlocksAndAssertNumTxes(1, 1)
+		ht.AssertWalletAccountBalance(
+			dave, defaultImportedAccount,
 			prevConfBalance+utxoAmt, prevUnconfBalance,
 		)
 	}
@@ -890,22 +750,15 @@ func testWalletImportPubKeyScenario(net *lntest.NetworkHarness, t *harnessTest,
 	// construct a PSBT that sends funds to Alice, which we'll then hand
 	// over to Carol to sign.
 	psbtSendFromImportedAccount(
-		t, dave, net.Alice, carol, defaultImportedAccount, addrType,
+		ht, dave, alice, carol, defaultImportedAccount, addrType,
 	)
 
 	// We'll now attempt to fund a channel.
 	//
 	// We'll have Carol generate another external address, which we'll
 	// import into Dave again.
-	ctxt, cancel := context.WithTimeout(ctxb, defaultTimeout)
-	defer cancel()
-	balanceResp, err := dave.WalletBalance(
-		ctxt, &lnrpc.WalletBalanceRequest{},
-	)
-	require.NoError(t.t, err)
-	require.Contains(
-		t.t, balanceResp.AccountBalance, defaultImportedAccount,
-	)
+	balanceResp := dave.RPC.WalletBalance()
+	require.Contains(ht, balanceResp.AccountBalance, defaultImportedAccount)
 	confBalance := balanceResp.
 		AccountBalance[defaultImportedAccount].ConfirmedBalance
 	importPubKey(1, confBalance, 0)
@@ -914,7 +767,7 @@ func testWalletImportPubKeyScenario(net *lntest.NetworkHarness, t *harnessTest,
 	// test payment, and close it. This contains several balance assertions
 	// along the way.
 	fundChanAndCloseFromImportedAccount(
-		t, dave, net.Alice, carol, defaultImportedAccount, addrType,
+		ht, dave, alice, carol, defaultImportedAccount, addrType,
 		utxoAmt, int64(funding.MaxBtcFundingAmount),
 	)
 }

lntest/itest/utils.go

@@ -5,20 +5,16 @@ import (
 	"crypto/rand"
 	"fmt"
 	"io"
-	"testing"
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil"
-	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/rpcclient"
-	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/go-errors/errors"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
 	"github.com/lightningnetwork/lnd/lntemp"
-	"github.com/lightningnetwork/lnd/lntemp/rpc"
 	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/lightningnetwork/lnd/lnwallet"
@@ -470,49 +466,3 @@ func findTxAtHeight(t *harnessTest, height int32,
 
 	return nil
 }
-
-// getOutputIndex returns the output index of the given address in the given
-// transaction.
-func getOutputIndex(t *harnessTest, miner *lntest.HarnessMiner,
-	txid *chainhash.Hash, addr string) int {
-
-	t.t.Helper()
-
-	// We'll then extract the raw transaction from the mempool in order to
-	// determine the index of the p2tr output.
-	tx, err := miner.Client.GetRawTransaction(txid)
-	require.NoError(t.t, err)
-
-	p2trOutputIndex := -1
-	for i, txOut := range tx.MsgTx().TxOut {
-		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
-			txOut.PkScript, miner.ActiveNet,
-		)
-		require.NoError(t.t, err)
-
-		if addrs[0].String() == addr {
-			p2trOutputIndex = i
-		}
-	}
-	require.Greater(t.t, p2trOutputIndex, -1)
-
-	return p2trOutputIndex
-}
-
-// acceptChannel is used to accept a single channel that comes across. This
-// should be run in a goroutine and is used to test nodes with the zero-conf
-// feature bit.
-func acceptChannel(t *testing.T, zeroConf bool, stream rpc.AcceptorClient) {
-	t.Helper()
-
-	req, err := stream.Recv()
-	require.NoError(t, err)
-
-	resp := &lnrpc.ChannelAcceptResponse{
-		Accept:        true,
-		PendingChanId: req.PendingChanId,
-		ZeroConf:      zeroConf,
-	}
-	err = stream.Send(resp)
-	require.NoError(t, err)
-}

lnwallet/channel.go

@@ -3566,9 +3566,12 @@ func (lc *LightningChannel) validateCommitmentSanity(theirLogCounter,
 	// balance to satisfy the final evaluated HTLC's.
 	switch {
 	case int64(ourBalance) < 0:
-		return ErrBelowChanReserve
+		return fmt.Errorf("%w: negative local balance",
+			ErrBelowChanReserve)
+
 	case int64(theirBalance) < 0:
-		return ErrBelowChanReserve
+		return fmt.Errorf("%w: negative remote balance",
+			ErrBelowChanReserve)
 	}
 
 	// Ensure that the fee being applied is enough to be relayed across the
@@ -3580,17 +3583,25 @@ func (lc *LightningChannel) validateCommitmentSanity(theirLogCounter,
 
 	// If the added HTLCs will decrease the balance, make sure they won't
 	// dip the local and remote balances below the channel reserves.
+	ourReserve := lnwire.NewMSatFromSatoshis(
+		lc.channelState.LocalChanCfg.ChanReserve,
+	)
+	theirReserve := lnwire.NewMSatFromSatoshis(
+		lc.channelState.RemoteChanCfg.ChanReserve,
+	)
+
 	switch {
-	case ourBalance < ourInitialBalance &&
-		ourBalance < lnwire.NewMSatFromSatoshis(
-			lc.channelState.LocalChanCfg.ChanReserve):
+	case ourBalance < ourInitialBalance && ourBalance < ourReserve:
+		lc.log.Debugf("Funds below chan reserve: ourBalance=%v, "+
+			"ourReserve=%v", ourBalance, ourReserve)
+		return fmt.Errorf("%w: our balance below chan reserve",
+			ErrBelowChanReserve)
 
-		return ErrBelowChanReserve
-	case theirBalance < theirInitialBalance &&
-		theirBalance < lnwire.NewMSatFromSatoshis(
-			lc.channelState.RemoteChanCfg.ChanReserve):
-
-		return ErrBelowChanReserve
+	case theirBalance < theirInitialBalance && theirBalance < theirReserve:
+		lc.log.Debugf("Funds below chan reserve: theirBalance=%v, "+
+			"theirReserve=%v", theirBalance, theirReserve)
+		return fmt.Errorf("%w: their balance below chan reserve",
+			ErrBelowChanReserve)
 	}
 
 	// validateUpdates take a set of updates, and validates them against

lnwallet/channel_test.go

@@ -2737,10 +2737,7 @@ func TestAddHTLCNegativeBalance(t *testing.T) {
 	htlcAmt = lnwire.NewMSatFromSatoshis(2 * btcutil.SatoshiPerBitcoin)
 	htlc, _ := createHTLC(numHTLCs+1, htlcAmt)
 	_, err = aliceChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected balance below channel reserve, instead "+
-			"got: %v", err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 }
 
 // assertNoChanSyncNeeded is a helper function that asserts that upon restart,
@@ -5642,10 +5639,8 @@ func TestDesyncHTLCs(t *testing.T) {
 	// balance is unavailable.
 	htlcAmt = lnwire.NewMSatFromSatoshis(1 * btcutil.SatoshiPerBitcoin)
 	htlc, _ = createHTLC(1, htlcAmt)
-	if _, err = aliceChannel.AddHTLC(htlc, nil); err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrInsufficientBalance, instead received: %v",
-			err)
-	}
+	_, err = aliceChannel.AddHTLC(htlc, nil)
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// Now do a state transition, which will ACK the FailHTLC, making Alice
 	// able to add the new HTLC.
@@ -6063,14 +6058,11 @@ func TestChanReserve(t *testing.T) {
 	htlc, _ = createHTLC(bobIndex, htlcAmt)
 	bobIndex++
 	_, err := bobChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// Alice will reject this htlc upon receiving the htlc.
-	if _, err := aliceChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	_, err = aliceChannel.ReceiveHTLC(htlc)
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// We must setup the channels again, since a violation of the channel
 	// constraints leads to channel shutdown.
@@ -6105,14 +6097,11 @@ func TestChanReserve(t *testing.T) {
 	htlc, _ = createHTLC(aliceIndex, htlcAmt)
 	aliceIndex++
 	_, err = aliceChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// Likewise, Bob will reject receiving the htlc because of the same reason.
-	if _, err := bobChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	_, err = bobChannel.ReceiveHTLC(htlc)
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// We must setup the channels again, since a violation of the channel
 	// constraints leads to channel shutdown.
@@ -6218,22 +6207,15 @@ func TestChanReserveRemoteInitiator(t *testing.T) {
 	// Bob should refuse to add this HTLC, since he realizes it will create
 	// an invalid commitment.
 	_, err = bobChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v",
-			err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// Of course Alice will also not have enough balance to add it herself.
 	_, err = aliceChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v",
-			err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 
 	// Same for Alice, she should refuse to accept this second HTLC.
-	if _, err := aliceChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	_, err = aliceChannel.ReceiveHTLC(htlc)
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 }
 
 // TestChanReserveLocalInitiatorDustHtlc tests that fee the initiator must pay
@@ -6276,9 +6258,7 @@ func TestChanReserveLocalInitiatorDustHtlc(t *testing.T) {
 	// Alice should realize that the fee she must pay to add this HTLC to
 	// the local commitment would take her below the channel reserve.
 	_, err = aliceChannel.AddHTLC(htlc, nil)
-	if err != ErrBelowChanReserve {
-		t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err)
-	}
+	require.ErrorIs(t, err, ErrBelowChanReserve)
 }
 
 // TestMinHTLC tests that the ErrBelowMinHTLC error is thrown if an HTLC is added