itest: add custom channel integration test

Co-authored-by: Olaoluwa Osuntokun <laolu32@gmail.com>
Co-authored-by: Gijs van Dam <gijs@lightning.engineering>
Co-authored-by: George Tsagkarelis <george.tsagkarelis@gmail.com>

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0
 	github.com/btcsuite/btclog v0.0.0-20241003133417-09c4e92e319c
 	github.com/btcsuite/btcwallet/walletdb v1.4.4
+	github.com/davecgh/go-spew v1.1.1
 	github.com/go-errors/errors v1.0.1
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.22.0
 	github.com/improbable-eng/grpc-web v0.12.0
@@ -35,6 +36,7 @@ require (
 	github.com/urfave/cli v1.22.9
 	go.etcd.io/bbolt v1.3.11
 	golang.org/x/crypto v0.25.0
+	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8
 	golang.org/x/net v0.27.0
 	golang.org/x/sync v0.8.0
 	google.golang.org/grpc v1.65.0
@@ -73,7 +75,6 @@ require (
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf // indirect
 	github.com/coreos/go-systemd/v22 v22.3.2 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/crypto/blake256 v1.0.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 // indirect
 	github.com/decred/dcrd/lru v1.1.2 // indirect
@@ -201,7 +202,6 @@ require (
 	go.uber.org/mock v0.4.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	go.uber.org/zap v1.23.0 // indirect
-	golang.org/x/exp v0.0.0-20240325151524-a685a6edb6d8 // indirect
 	golang.org/x/mod v0.17.0 // indirect
 	golang.org/x/sys v0.22.0 // indirect
 	golang.org/x/term v0.22.0 // indirect

itest/assertions.go

@@ -3,14 +3,18 @@ package itest
 import (
 	"context"
 	"fmt"
+	"testing"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/taproot-assets/taprpc"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
 	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/proto"
 )
 
 // shutdownAndAssert shuts down the given node and asserts that no errors
@@ -172,24 +176,25 @@ func assertChannelClosed(ctx context.Context, t *harnessTest,
 	// block.
 	block := mineBlocks(t, net, 1, 1)[0]
 
-	closingTxid, err := net.WaitForChannelClose(closeUpdates)
+	closingUpdate, err := net.WaitForChannelClose(closeUpdates)
 	require.NoError(t.t, err, "error while waiting for channel close")
 
+	closingTxid, err := chainhash.NewHash(closingUpdate.ClosingTxid)
+	require.NoError(t.t, err)
 	assertTxInBlock(t, block, closingTxid)
 
 	// Finally, the transaction should no longer be in the waiting close
 	// state as we've just mined a block that should include the closing
 	// transaction.
 	err = wait.Predicate(func() bool {
-		pendingChansRequest := &lnrpc.PendingChannelsRequest{}
-		pendingChanResp, err := node.PendingChannels(
-			ctx, pendingChansRequest,
+		resp, err := node.PendingChannels(
+			ctx, &lnrpc.PendingChannelsRequest{},
 		)
 		if err != nil {
 			return false
 		}
 
-		for _, pendingClose := range pendingChanResp.WaitingCloseChannels {
+		for _, pendingClose := range resp.WaitingCloseChannels {
 			if pendingClose.Channel.ChannelPoint == chanPointStr {
 				return false
 			}
@@ -203,3 +208,34 @@ func assertChannelClosed(ctx context.Context, t *harnessTest,
 
 	return closingTxid
 }
+
+func assertSweepExists(t *testing.T, node *HarnessNode,
+	witnessType walletrpc.WitnessType) {
+
+	ctxb := context.Background()
+	err := wait.NoError(func() error {
+		pendingSweeps, err := node.WalletKitClient.PendingSweeps(
+			ctxb, &walletrpc.PendingSweepsRequest{},
+		)
+		if err != nil {
+			return err
+		}
+
+		for _, sweep := range pendingSweeps.PendingSweeps {
+			if sweep.WitnessType == witnessType {
+				return nil
+			}
+		}
+
+		return fmt.Errorf("failed to find second level sweep: %v",
+			toProtoJSON(t, pendingSweeps))
+	}, defaultTimeout)
+	require.NoError(t, err)
+}
+
+func toProtoJSON(t *testing.T, resp proto.Message) string {
+	jsonBytes, err := taprpc.ProtoJSONMarshalOpts.Marshal(resp)
+	require.NoError(t, err)
+
+	return string(jsonBytes)
+}