contractcourt test: add TestChannelArbitratorCommitFailure

contractcourt/channel_arbitrator_test.go

@@ -14,10 +14,12 @@ import (
 )
 
 type mockArbitratorLog struct {
-	state     ArbitratorState
-	newStates chan ArbitratorState
-	failLog   bool
-	failFetch error
+	state           ArbitratorState
+	newStates       chan ArbitratorState
+	failLog         bool
+	failFetch       error
+	failCommit      bool
+	failCommitState ArbitratorState
 }
 
 // A compile time check to ensure mockArbitratorLog meets the ArbitratorLog
@@ -29,6 +31,10 @@ func (b *mockArbitratorLog) CurrentState() (ArbitratorState, error) {
 }
 
 func (b *mockArbitratorLog) CommitState(s ArbitratorState) error {
+	if b.failCommit && s == b.failCommitState {
+		return fmt.Errorf("intentional commit error at state %v",
+			b.failCommitState)
+	}
 	b.state = s
 	b.newStates <- s
 	return nil
@@ -732,3 +738,89 @@ func TestChannelArbitratorPersistence(t *testing.T) {
 		t.Fatalf("contract was not resolved")
 	}
 }
+
+// TestChannelArbitratorCommitFailure tests that the channel arbitrator is able
+// to recover from a failed CommitState call at restart.
+func TestChannelArbitratorCommitFailure(t *testing.T) {
+	// Start out with a log that will fail committing to StateContractClosed.
+	log := &mockArbitratorLog{
+		state:           StateDefault,
+		newStates:       make(chan ArbitratorState, 5),
+		failCommit:      true,
+		failCommitState: StateContractClosed,
+	}
+
+	chanArb, resolved, err := createTestChannelArbitrator(log)
+	if err != nil {
+		t.Fatalf("unable to create ChannelArbitrator: %v", err)
+	}
+
+	if err := chanArb.Start(); err != nil {
+		t.Fatalf("unable to start ChannelArbitrator: %v", err)
+	}
+
+	// It should start in StateDefault.
+	assertState(t, chanArb, StateDefault)
+
+	closed := make(chan struct{})
+	chanArb.cfg.MarkChannelClosed = func(*channeldb.ChannelCloseSummary) error {
+		close(closed)
+		return nil
+	}
+
+	// Send a remote force close event.
+	commitSpend := &chainntnfs.SpendDetail{
+		SpenderTxHash: &chainhash.Hash{},
+	}
+
+	uniClose := &lnwallet.UnilateralCloseSummary{
+		SpendDetail:     commitSpend,
+		HtlcResolutions: &lnwallet.HtlcResolutions{},
+	}
+	chanArb.cfg.ChainEvents.RemoteUnilateralClosure <- uniClose
+
+	select {
+	case <-closed:
+	case <-time.After(5 * time.Second):
+		t.Fatalf("channel was not marked closed")
+	}
+
+	// Since the channel was marked closed in the database, but the commit
+	// to the next state failed, the state should still be StateDefault.
+	time.Sleep(100 * time.Millisecond)
+	if log.state != StateDefault {
+		t.Fatalf("expected to stay in StateDefault")
+	}
+	chanArb.Stop()
+
+	// Start the arbitrator again, with IsPendingClose reporting the
+	// channel closed in the database.
+	chanArb, resolved, err = createTestChannelArbitrator(log)
+	if err != nil {
+		t.Fatalf("unable to create ChannelArbitrator: %v", err)
+	}
+
+	log.failCommit = false
+
+	chanArb.cfg.IsPendingClose = true
+	chanArb.cfg.ClosingHeight = 100
+	chanArb.cfg.CloseType = channeldb.RemoteForceClose
+
+	if err := chanArb.Start(); err != nil {
+		t.Fatalf("unable to start ChannelArbitrator: %v", err)
+	}
+
+	// Since the channel is marked closed in the database, it should
+	// advance to StateContractClosed and StateFullyResolved.
+	assertStateTransitions(
+		t, log.newStates, StateContractClosed, StateFullyResolved,
+	)
+
+	// It should also mark the channel as resolved.
+	select {
+	case <-resolved:
+		// Expected.
+	case <-time.After(5 * time.Second):
+		t.Fatalf("contract was not resolved")
+	}
+}