multi: move itest out of lntest

This commit moves all the test cases living in `itest` out of `lntest`,
further making `lntest` an independent package for general testing.

itest/lnd_res_handoff_test.go

@@ -0,0 +1,99 @@
+package itest
+
+import (
+	"time"
+
+	"github.com/btcsuite/btcd/btcutil"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lntemp"
+	"github.com/stretchr/testify/require"
+)
+
+// testResHandoff tests that the contractcourt is able to properly hand-off
+// resolution messages to the switch.
+func testResHandoff(ht *lntemp.HarnessTest) {
+	const (
+		chanAmt    = btcutil.Amount(1000000)
+		paymentAmt = 50000
+	)
+
+	alice, bob := ht.Alice, ht.Bob
+
+	// First we'll create a channel between Alice and Bob.
+	ht.EnsureConnected(alice, bob)
+
+	params := lntemp.OpenChannelParams{Amt: chanAmt}
+	chanPointAlice := ht.OpenChannel(alice, bob, params)
+
+	// Create a new node Carol that will be in hodl mode. This is used to
+	// trigger the behavior of checkRemoteDanglingActions in the
+	// contractcourt. This will cause Bob to fail the HTLC back to Alice.
+	carol := ht.NewNode("Carol", []string{"--hodl.commit"})
+	defer ht.Shutdown(carol)
+
+	// Connect Bob to Carol.
+	ht.ConnectNodes(bob, carol)
+
+	// Open a channel between Bob and Carol.
+	chanPointCarol := ht.OpenChannel(bob, carol, params)
+
+	// Wait for Alice to see the channel edge in the graph.
+	ht.AssertTopologyChannelOpen(alice, chanPointCarol)
+
+	// We'll create an invoice for Carol that Alice will attempt to pay.
+	// Since Carol is in hodl.commit mode, she won't send back any commit
+	// sigs.
+	carolPayReqs, _, _ := ht.CreatePayReqs(carol, paymentAmt, 1)
+
+	// Alice will now attempt to fulfill the invoice.
+	ht.CompletePaymentRequestsNoWait(alice, carolPayReqs, chanPointAlice)
+
+	// Wait until Carol has received the Add, CommitSig from Bob, and has
+	// responded with a RevokeAndAck. We expect NumUpdates to be 1 meaning
+	// Carol's CommitHeight is 1.
+	ht.AssertChannelCommitHeight(carol, chanPointCarol, 1)
+
+	// Before we shutdown Alice, we'll assert that she only has 1 update.
+	ht.AssertChannelCommitHeight(alice, chanPointAlice, 1)
+
+	// We'll shutdown Alice so that Bob can't connect to her.
+	restartAlice := ht.SuspendNode(alice)
+
+	// Bob will now force close his channel with Carol such that resolution
+	// messages are created and forwarded backwards to Alice.
+	ht.CloseChannelAssertPending(bob, chanPointCarol, true)
+
+	// The channel should be listed in the PendingChannels result.
+	ht.AssertNumWaitingClose(bob, 1)
+
+	// Mine a block to confirm the closing tx.
+	ht.MineBlocks(1)
+
+	// We sleep here so we can be sure that the hand-off has occurred from
+	// Bob's contractcourt to Bob's htlcswitch. This sleep could be removed
+	// if there was some feedback (i.e. API in switch) that allowed for
+	// querying the state of resolution messages.
+	time.Sleep(10 * time.Second)
+
+	// Mine blocks until Bob has no waiting close channels. This tests that
+	// the circuit-deletion logic is skipped if a resolution message
+	// exists.
+	ht.CleanupForceClose(bob, chanPointCarol)
+
+	// We will now restart Bob so that we can test whether the resolution
+	// messages are re-forwarded on start-up.
+	ht.RestartNode(bob)
+
+	// We'll now also restart Alice and connect her with Bob.
+	require.NoError(ht, restartAlice())
+
+	ht.EnsureConnected(alice, bob)
+
+	// We'll assert that Alice has received the failure resolution message.
+	ht.AssertChannelCommitHeight(alice, chanPointAlice, 2)
+
+	// Assert that Alice's payment failed.
+	ht.AssertFirstHTLCError(alice, lnrpc.Failure_PERMANENT_CHANNEL_FAILURE)
+
+	ht.CloseChannel(alice, chanPointAlice)
+}