From f930dd42a6294f9ba31fba6e891a6a180411bd43 Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Fri, 1 Nov 2019 12:01:34 +0100
Subject: [PATCH] cnct/test: add outgoing contest resolver test

---
 .../htlc_outgoing_contest_resolver_test.go    | 187 ++++++++++++++++++
 1 file changed, 187 insertions(+)
 create mode 100644 contractcourt/htlc_outgoing_contest_resolver_test.go

diff --git a/contractcourt/htlc_outgoing_contest_resolver_test.go b/contractcourt/htlc_outgoing_contest_resolver_test.go
new file mode 100644
index 00000000..244b438d
--- /dev/null
+++ b/contractcourt/htlc_outgoing_contest_resolver_test.go
@@ -0,0 +1,187 @@
+package contractcourt
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/chainntnfs"
+	"github.com/lightningnetwork/lnd/input"
+	"github.com/lightningnetwork/lnd/lntypes"
+	"github.com/lightningnetwork/lnd/lnwallet"
+)
+
+const (
+	outgoingContestHtlcExpiry = 110
+)
+
+// TestHtlcOutgoingResolverTimeout tests resolution of an offered htlc that
+// timed out.
+func TestHtlcOutgoingResolverTimeout(t *testing.T) {
+	t.Parallel()
+	defer timeout(t)()
+
+	// Setup the resolver with our test resolution.
+	ctx := newOutgoingResolverTestContext(t)
+
+	// Start the resolution process in a goroutine.
+	ctx.resolve()
+
+	// Notify arrival of the block after which the timeout path of the htlc
+	// unlocks.
+	ctx.notifyEpoch(outgoingContestHtlcExpiry - 1)
+
+	// Assert that the resolver finishes without error and transforms in a
+	// timeout resolver.
+	ctx.waitForResult(true)
+}
+
+// TestHtlcOutgoingResolverRemoteClaim tests resolution of an offered htlc that
+// is claimed by the remote party.
+func TestHtlcOutgoingResolverRemoteClaim(t *testing.T) {
+	t.Parallel()
+	defer timeout(t)()
+
+	// Setup the resolver with our test resolution and start the resolution
+	// process.
+	ctx := newOutgoingResolverTestContext(t)
+	ctx.resolve()
+
+	// The remote party sweeps the htlc. Notify our resolver of this event.
+	preimage := lntypes.Preimage{}
+	ctx.notifier.spendChan <- &chainntnfs.SpendDetail{
+		SpendingTx: &wire.MsgTx{
+			TxIn: []*wire.TxIn{
+				{
+					Witness: [][]byte{
+						{0}, {1}, {2}, preimage[:],
+					},
+				},
+			},
+		},
+	}
+
+	// We expect the extracted preimage to be added to the witness beacon.
+	<-ctx.preimageDB.newPreimages
+
+	// We also expect a resolution message to the incoming side of the
+	// circuit.
+	<-ctx.resolutionChan
+
+	// Assert that the resolver finishes without error.
+	ctx.waitForResult(false)
+}
+
+type resolveResult struct {
+	err          error
+	nextResolver ContractResolver
+}
+
+type outgoingResolverTestContext struct {
+	resolver           *htlcOutgoingContestResolver
+	notifier           *mockNotifier
+	preimageDB         *mockWitnessBeacon
+	resolverResultChan chan resolveResult
+	resolutionChan     chan ResolutionMsg
+	t                  *testing.T
+}
+
+func newOutgoingResolverTestContext(t *testing.T) *outgoingResolverTestContext {
+	notifier := &mockNotifier{
+		epochChan: make(chan *chainntnfs.BlockEpoch),
+		spendChan: make(chan *chainntnfs.SpendDetail),
+		confChan:  make(chan *chainntnfs.TxConfirmation),
+	}
+
+	checkPointChan := make(chan struct{}, 1)
+	resolutionChan := make(chan ResolutionMsg, 1)
+
+	preimageDB := newMockWitnessBeacon()
+
+	chainCfg := ChannelArbitratorConfig{
+		ChainArbitratorConfig: ChainArbitratorConfig{
+			Notifier:   notifier,
+			PreimageDB: preimageDB,
+			DeliverResolutionMsg: func(msgs ...ResolutionMsg) error {
+				if len(msgs) != 1 {
+					return fmt.Errorf("expected 1 "+
+						"resolution msg, instead got %v",
+						len(msgs))
+				}
+
+				resolutionChan <- msgs[0]
+				return nil
+			},
+		},
+	}
+
+	outgoingRes := lnwallet.OutgoingHtlcResolution{
+		Expiry: outgoingContestHtlcExpiry,
+		SweepSignDesc: input.SignDescriptor{
+			Output: &wire.TxOut{},
+		},
+	}
+
+	resolver := &htlcOutgoingContestResolver{
+		htlcTimeoutResolver: htlcTimeoutResolver{
+			ResolverKit: ResolverKit{
+				ChannelArbitratorConfig: chainCfg,
+				Checkpoint: func(_ ContractResolver) error {
+					checkPointChan <- struct{}{}
+					return nil
+				},
+			},
+			htlcResolution: outgoingRes,
+		},
+	}
+
+	return &outgoingResolverTestContext{
+		resolver:       resolver,
+		notifier:       notifier,
+		preimageDB:     preimageDB,
+		resolutionChan: resolutionChan,
+		t:              t,
+	}
+}
+
+func (i *outgoingResolverTestContext) resolve() {
+	// Start resolver.
+	i.resolverResultChan = make(chan resolveResult, 1)
+	go func() {
+		nextResolver, err := i.resolver.Resolve()
+		i.resolverResultChan <- resolveResult{
+			nextResolver: nextResolver,
+			err:          err,
+		}
+	}()
+
+	// Notify initial block height.
+	i.notifyEpoch(testInitialBlockHeight)
+}
+
+func (i *outgoingResolverTestContext) notifyEpoch(height int32) {
+	i.notifier.epochChan <- &chainntnfs.BlockEpoch{
+		Height: height,
+	}
+}
+
+func (i *outgoingResolverTestContext) waitForResult(expectTimeoutRes bool) {
+	i.t.Helper()
+
+	result := <-i.resolverResultChan
+	if result.err != nil {
+		i.t.Fatal(result.err)
+	}
+
+	if !expectTimeoutRes {
+		if result.nextResolver != nil {
+			i.t.Fatal("expected no next resolver")
+		}
+		return
+	}
+
+	_, ok := result.nextResolver.(*htlcTimeoutResolver)
+	if !ok {
+		i.t.Fatal("expected htlcTimeoutResolver")
+	}
+}