lntest: add CPFP integration test

lntest/itest/lnd_test.go

@@ -13733,6 +13733,10 @@ var testsCases = []*testCase{
 		name: "hold invoice sender persistence",
 		test: testHoldInvoicePersistence,
 	},
+	{
+		name: "cpfp",
+		test: testCPFP,
+	},
 }
 
 // TestLightningNetworkDaemon performs a series of integration tests amongst a

lntest/itest/onchain.go

@@ -0,0 +1,160 @@
+// +build rpctest
+
+package itest
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	"github.com/btcsuite/btcd/txscript"
+	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
+	"github.com/lightningnetwork/lnd/lntest"
+	"github.com/lightningnetwork/lnd/sweep"
+)
+
+// testCPFP ensures that the daemon can bump an unconfirmed  transaction's fee
+// 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) {
+	// Skip this test for neutrino, as it's not aware of mempool
+	// transactions.
+	if net.BackendCfg.Name() == "neutrino" {
+		t.Skipf("skipping reorg 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()
+	ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
+	err := net.SendCoins(ctxt, btcutil.SatoshiPerBitcoin, net.Alice)
+	if err != nil {
+		t.Fatalf("unable to send coins to alice: %v", err)
+	}
+
+	// Create an address for Bob to send the coins to.
+	addrReq := &lnrpc.NewAddressRequest{
+		Type: lnrpc.AddressType_WITNESS_PUBKEY_HASH,
+	}
+	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
+	resp, err := net.Bob.NewAddress(ctxt, addrReq)
+	if err != nil {
+		t.Fatalf("unable to get new address for bob: %v", err)
+	}
+
+	// Send the coins from Alice to Bob. We should expect a transaction to
+	// be broadcast and seen in the mempool.
+	sendReq := &lnrpc.SendCoinsRequest{
+		Addr:   resp.Address,
+		Amount: btcutil.SatoshiPerBitcoin,
+	}
+	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
+	if _, err = net.Alice.SendCoins(ctxt, sendReq); err != nil {
+		t.Fatalf("unable to send coins to bob: %v", err)
+	}
+
+	txid, err := waitForTxInMempool(net.Miner.Node, minerMempoolTimeout)
+	if err != nil {
+		t.Fatalf("expected one mempool transaction: %v", err)
+	}
+
+	// We'll then extract the raw transaction from the mempool in order to
+	// determine the index of Bob's output.
+	tx, err := net.Miner.Node.GetRawTransaction(txid)
+	if err != nil {
+		t.Fatalf("unable to extract raw transaction from mempool: %v",
+			err)
+	}
+	bobOutputIdx := -1
+	for i, txOut := range tx.MsgTx().TxOut {
+		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+			txOut.PkScript, net.Miner.ActiveNet,
+		)
+		if err != nil {
+			t.Fatalf("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")
+	}
+
+	// We'll attempt to bump the fee of this transaction by performing a
+	// CPFP from Alice's point of view.
+	op := &lnrpc.OutPoint{
+		TxidBytes:   txid[:],
+		OutputIndex: uint32(bobOutputIdx),
+	}
+	bumpFeeReq := &walletrpc.BumpFeeRequest{
+		Outpoint:   op,
+		SatPerByte: uint32(sweep.DefaultMaxFeeRate.FeePerKVByte() / 1000),
+	}
+	ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
+	_, err = net.Bob.WalletKitClient.BumpFee(ctxt, bumpFeeReq)
+	if err != nil {
+		t.Fatalf("unable to bump fee: %v", err)
+	}
+
+	// We should now expect to see two transactions within the mempool, a
+	// parent and its child.
+	_, err = waitForNTxsInMempool(net.Miner.Node, 2, minerMempoolTimeout)
+	if err != nil {
+		t.Fatalf("expected two mempool transactions: %v", err)
+	}
+
+	// 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 := net.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))
+	}
+	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.SatPerByte != bumpFeeReq.SatPerByte {
+		t.Fatalf("expected sweep sat per byte %v, got %v",
+			bumpFeeReq.SatPerByte, pendingSweep.SatPerByte)
+	}
+
+	// Mine a block to clean up the unconfirmed transactions.
+	mineBlocks(t, net, 1, 2)
+
+	// The input used to CPFP should no longer be pending.
+	err = lntest.WaitNoError(func() error {
+		req := &walletrpc.PendingSweepsRequest{}
+		ctxt, _ = context.WithTimeout(ctxb, defaultTimeout)
+		resp, err := net.Bob.WalletKitClient.PendingSweeps(ctxt, req)
+		if err != nil {
+			return fmt.Errorf("unable to retrieve bob's pending "+
+				"sweeps: %v", err)
+		}
+		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())
+	}
+}

lntest/node.go

@@ -15,11 +15,6 @@ import (
 	"sync"
 	"time"
 
-	"golang.org/x/net/context"
-	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials"
-	macaroon "gopkg.in/macaroon.v2"
-
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
@@ -29,7 +24,12 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/invoicesrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
 	"github.com/lightningnetwork/lnd/macaroons"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	macaroon "gopkg.in/macaroon.v2"
 )
 
 var (
@@ -250,9 +250,10 @@ type HarnessNode struct {
 
 	invoicesrpc.InvoicesClient
 
-	// RouterClient cannot be embedded, because a name collision would occur
-	// on the main rpc SendPayment.
+	// RouterClient and WalletKitClient cannot be embedded, because a name
+	// collision would occur with LightningClient.
 	RouterClient    routerrpc.RouterClient
+	WalletKitClient walletrpc.WalletKitClient
 }
 
 // Assert *HarnessNode implements the lnrpc.LightningClient interface.
@@ -503,6 +504,7 @@ func (hn *HarnessNode) initLightningClient(conn *grpc.ClientConn) error {
 	hn.LightningClient = lnrpc.NewLightningClient(conn)
 	hn.InvoicesClient = invoicesrpc.NewInvoicesClient(conn)
 	hn.RouterClient = routerrpc.NewRouterClient(conn)
+	hn.WalletKitClient = walletrpc.NewWalletKitClient(conn)
 
 	// Set the harness node's pubkey to what the node claims in GetInfo.
 	err := hn.FetchNodeInfo()