sweep: add sweeper test

sweep/backend_mock_test.go

@@ -0,0 +1,110 @@
+package sweep
+
+import (
+	"sync"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/lnwallet"
+)
+
+// mockBackend simulates a chain backend for realistic behaviour in unit tests
+// around double spends.
+type mockBackend struct {
+	lock sync.Mutex
+
+	notifier *MockNotifier
+
+	confirmedSpendInputs map[wire.OutPoint]struct{}
+
+	unconfirmedTxes        map[chainhash.Hash]*wire.MsgTx
+	unconfirmedSpendInputs map[wire.OutPoint]struct{}
+}
+
+func newMockBackend(notifier *MockNotifier) *mockBackend {
+	return &mockBackend{
+		notifier:               notifier,
+		unconfirmedTxes:        make(map[chainhash.Hash]*wire.MsgTx),
+		confirmedSpendInputs:   make(map[wire.OutPoint]struct{}),
+		unconfirmedSpendInputs: make(map[wire.OutPoint]struct{}),
+	}
+}
+
+func (b *mockBackend) publishTransaction(tx *wire.MsgTx) error {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	txHash := tx.TxHash()
+	if _, ok := b.unconfirmedTxes[txHash]; ok {
+		// Tx already exists
+		testLog.Tracef("mockBackend duplicate tx %v", tx.TxHash())
+		return lnwallet.ErrDoubleSpend
+	}
+
+	for _, in := range tx.TxIn {
+		if _, ok := b.unconfirmedSpendInputs[in.PreviousOutPoint]; ok {
+			// Double spend
+			testLog.Tracef("mockBackend double spend tx %v", tx.TxHash())
+			return lnwallet.ErrDoubleSpend
+		}
+
+		if _, ok := b.confirmedSpendInputs[in.PreviousOutPoint]; ok {
+			// Already included in block
+			testLog.Tracef("mockBackend already in block tx %v", tx.TxHash())
+			return lnwallet.ErrDoubleSpend
+		}
+	}
+
+	b.unconfirmedTxes[txHash] = tx
+	for _, in := range tx.TxIn {
+		b.unconfirmedSpendInputs[in.PreviousOutPoint] = struct{}{}
+	}
+
+	testLog.Tracef("mockBackend publish tx %v", tx.TxHash())
+
+	return nil
+}
+
+func (b *mockBackend) deleteUnconfirmed(txHash chainhash.Hash) {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	tx, ok := b.unconfirmedTxes[txHash]
+	if !ok {
+		// Tx already exists
+		testLog.Errorf("mockBackend delete tx not existing %v", txHash)
+		return
+	}
+
+	testLog.Tracef("mockBackend delete tx %v", tx.TxHash())
+	delete(b.unconfirmedTxes, txHash)
+	for _, in := range tx.TxIn {
+		delete(b.unconfirmedSpendInputs, in.PreviousOutPoint)
+	}
+}
+
+func (b *mockBackend) mine() {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	notifications := make(map[wire.OutPoint]*wire.MsgTx)
+	for _, tx := range b.unconfirmedTxes {
+		testLog.Tracef("mockBackend mining tx %v", tx.TxHash())
+		for _, in := range tx.TxIn {
+			b.confirmedSpendInputs[in.PreviousOutPoint] = struct{}{}
+			notifications[in.PreviousOutPoint] = tx
+		}
+	}
+	b.unconfirmedSpendInputs = make(map[wire.OutPoint]struct{})
+	b.unconfirmedTxes = make(map[chainhash.Hash]*wire.MsgTx)
+
+	for outpoint, tx := range notifications {
+		testLog.Tracef("mockBackend delivering spend ntfn for %v",
+			outpoint)
+		b.notifier.SpendOutpoint(outpoint, *tx)
+	}
+}
+
+func (b *mockBackend) isDone() bool {
+	return len(b.unconfirmedTxes) == 0
+}