multi: introduce new paymentsDB package

We introduce a new package paymentsDB and start by moving the
payment specifc errors from the channeldb package to the
paymentsDB package. We also fix linter issues which showed up
due to changing this code part.

channeldb/payments_kv_store_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
+	paymentsdb "github.com/lightningnetwork/lnd/payments/db"
 	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/tlv"
@@ -193,7 +194,7 @@ func TestKVPaymentsDBSwitchFail(t *testing.T) {
 	// Attempt a final payment, which should now fail since the prior
 	// payment succeed.
 	err = paymentDB.InitPayment(info.PaymentIdentifier, info)
-	if !errors.Is(err, ErrAlreadyPaid) {
+	if !errors.Is(err, paymentsdb.ErrAlreadyPaid) {
 		t.Fatalf("unable to send htlc message: %v", err)
 	}
 }
@@ -228,7 +229,7 @@ func TestKVPaymentsDBSwitchDoubleSend(t *testing.T) {
 	// payment hash, should result in error indicating that payment has
 	// already been sent.
 	err = paymentDB.InitPayment(info.PaymentIdentifier, info)
-	require.ErrorIs(t, err, ErrPaymentExists)
+	require.ErrorIs(t, err, paymentsdb.ErrPaymentExists)
 
 	// Record an attempt.
 	_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, attempt)
@@ -246,7 +247,7 @@ func TestKVPaymentsDBSwitchDoubleSend(t *testing.T) {
 
 	// Sends base htlc message which initiate StatusInFlight.
 	err = paymentDB.InitPayment(info.PaymentIdentifier, info)
-	if !errors.Is(err, ErrPaymentInFlight) {
+	if !errors.Is(err, paymentsdb.ErrPaymentInFlight) {
 		t.Fatalf("payment control wrong behaviour: " +
 			"double sending must trigger ErrPaymentInFlight error")
 	}
@@ -269,7 +270,7 @@ func TestKVPaymentsDBSwitchDoubleSend(t *testing.T) {
 	)
 
 	err = paymentDB.InitPayment(info.PaymentIdentifier, info)
-	if !errors.Is(err, ErrAlreadyPaid) {
+	if !errors.Is(err, paymentsdb.ErrAlreadyPaid) {
 		t.Fatalf("unable to send htlc message: %v", err)
 	}
 }
@@ -294,9 +295,7 @@ func TestKVPaymentsDBSuccessesWithoutInFlight(t *testing.T) {
 			Preimage: preimg,
 		},
 	)
-	if err != ErrPaymentNotInitiated {
-		t.Fatalf("expected ErrPaymentNotInitiated, got %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrPaymentNotInitiated)
 }
 
 // TestKVPaymentsDBFailsWithoutInFlight checks that a strict payment
@@ -314,9 +313,7 @@ func TestKVPaymentsDBFailsWithoutInFlight(t *testing.T) {
 
 	// Calling Fail should return an error.
 	_, err = paymentDB.Fail(info.PaymentIdentifier, FailureReasonNoRoute)
-	if err != ErrPaymentNotInitiated {
-		t.Fatalf("expected ErrPaymentNotInitiated, got %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrPaymentNotInitiated)
 }
 
 // TestKVPaymentsDBDeleteNonInFlight checks that calling DeletePayments only
@@ -780,7 +777,7 @@ func TestKVPaymentsDBMultiShard(t *testing.T) {
 		b := *attempt
 		b.AttemptID = 3
 		_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
-		require.ErrorIs(t, err, ErrValueExceedsAmt)
+		require.ErrorIs(t, err, paymentsdb.ErrValueExceedsAmt)
 
 		// Fail the second attempt.
 		a := attempts[1]
@@ -880,9 +877,13 @@ func TestKVPaymentsDBMultiShard(t *testing.T) {
 		b.AttemptID = 3
 		_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
 		if test.settleFirst {
-			require.ErrorIs(t, err, ErrPaymentPendingSettled)
+			require.ErrorIs(
+				t, err, paymentsdb.ErrPaymentPendingSettled,
+			)
 		} else {
-			require.ErrorIs(t, err, ErrPaymentPendingFailed)
+			require.ErrorIs(
+				t, err, paymentsdb.ErrPaymentPendingFailed,
+			)
 		}
 
 		assertPaymentStatus(
@@ -951,21 +952,21 @@ func TestKVPaymentsDBMultiShard(t *testing.T) {
 		// settled.
 		case test.settleFirst && !test.settleLast:
 			finalStatus = StatusSucceeded
-			registerErr = ErrPaymentAlreadySucceeded
+			registerErr = paymentsdb.ErrPaymentAlreadySucceeded
 
 		case !test.settleFirst && test.settleLast:
 			finalStatus = StatusSucceeded
-			registerErr = ErrPaymentAlreadySucceeded
+			registerErr = paymentsdb.ErrPaymentAlreadySucceeded
 
 		// If both failed, we end up in a failed status.
 		case !test.settleFirst && !test.settleLast:
 			finalStatus = StatusFailed
-			registerErr = ErrPaymentAlreadyFailed
+			registerErr = paymentsdb.ErrPaymentAlreadyFailed
 
 		// Otherwise, the payment has a succeed status.
 		case test.settleFirst && test.settleLast:
 			finalStatus = StatusSucceeded
-			registerErr = ErrPaymentAlreadySucceeded
+			registerErr = paymentsdb.ErrPaymentAlreadySucceeded
 		}
 
 		assertPaymentStatus(
@@ -1021,27 +1022,21 @@ func TestKVPaymentsDBMPPRecordValidation(t *testing.T) {
 	b.AttemptID = 1
 	b.Route.FinalHop().MPP = nil
 	_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
-	if err != ErrMPPayment {
-		t.Fatalf("expected ErrMPPayment, got: %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrMPPayment)
 
 	// Try to register attempt one with a different payment address.
 	b.Route.FinalHop().MPP = record.NewMPP(
 		info.Value, [32]byte{2},
 	)
 	_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
-	if err != ErrMPPPaymentAddrMismatch {
-		t.Fatalf("expected ErrMPPPaymentAddrMismatch, got: %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrMPPPaymentAddrMismatch)
 
 	// Try registering one with a different total amount.
 	b.Route.FinalHop().MPP = record.NewMPP(
 		info.Value/2, [32]byte{1},
 	)
 	_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
-	if err != ErrMPPTotalAmountMismatch {
-		t.Fatalf("expected ErrMPPTotalAmountMismatch, got: %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrMPPTotalAmountMismatch)
 
 	// Create and init a new payment. This time we'll check that we cannot
 	// register an MPP attempt if we already registered a non-MPP one.
@@ -1063,9 +1058,7 @@ func TestKVPaymentsDBMPPRecordValidation(t *testing.T) {
 	)
 
 	_, err = paymentDB.RegisterAttempt(info.PaymentIdentifier, &b)
-	if err != ErrNonMPPayment {
-		t.Fatalf("expected ErrNonMPPayment, got: %v", err)
-	}
+	require.ErrorIs(t, err, paymentsdb.ErrNonMPPayment)
 }
 
 // TestDeleteFailedAttempts checks that DeleteFailedAttempts properly removes
@@ -1171,7 +1164,7 @@ func assertPaymentStatus(t *testing.T, p *KVPaymentsDB,
 	t.Helper()
 
 	payment, err := p.FetchPayment(hash)
-	if errors.Is(err, ErrPaymentNotInitiated) {
+	if errors.Is(err, paymentsdb.ErrPaymentNotInitiated) {
 		return
 	}
 	if err != nil {
@@ -1271,7 +1264,7 @@ func fetchPaymentIndexEntry(_ *testing.T, p *KVPaymentsDB,
 
 		indexValue := indexBucket.Get(key)
 		if indexValue == nil {
-			return errNoSequenceNrIndex
+			return paymentsdb.ErrNoSequenceNrIndex
 		}
 
 		r := bytes.NewReader(indexValue)
@@ -1307,7 +1300,7 @@ func assertPaymentIndex(t *testing.T, p *KVPaymentsDB,
 // exist.
 func assertNoIndex(t *testing.T, p *KVPaymentsDB, seqNr uint64) {
 	_, err := fetchPaymentIndexEntry(t, p, seqNr)
-	require.Equal(t, errNoSequenceNrIndex, err)
+	require.Equal(t, paymentsdb.ErrNoSequenceNrIndex, err)
 }
 
 // payment is a helper structure that holds basic information on a test payment,
@@ -1669,14 +1662,14 @@ func TestFetchPaymentWithSequenceNumber(t *testing.T) {
 			name:           "lookup non-existent duplicate",
 			paymentHash:    hasDuplicates.PaymentIdentifier,
 			sequenceNumber: 999999,
-			expectedErr:    ErrDuplicateNotFound,
+			expectedErr:    paymentsdb.ErrDuplicateNotFound,
 		},
 		{
 			name: "lookup duplicate, no duplicates " +
 				"bucket",
 			paymentHash:    noDuplicates.PaymentIdentifier,
 			sequenceNumber: duplicateTwoSeqNr,
-			expectedErr:    ErrNoDuplicateBucket,
+			expectedErr:    paymentsdb.ErrNoDuplicateBucket,
 		},
 	}