chore(op-e2e): assert that the channel actually timed out (#11998)

* assert that the channel actually timed out

* fmt

op-e2e/actions/helpers/l2_verifier.go

@@ -49,8 +49,9 @@ type L2Verifier struct {
 	drainer event.Drainer
 
 	// L2 rollup
-	engine     *engine.EngineController
-	derivation *derive.DerivationPipeline
+	engine            *engine.EngineController
+	derivationMetrics *testutils.TestDerivationMetrics
+	derivation        *derive.DerivationPipeline
 
 	safeHeadListener rollup.SafeHeadListener
 	syncCfg          *sync.Config
@@ -88,7 +89,8 @@ type safeDB interface {
 func NewL2Verifier(t Testing, log log.Logger, l1 derive.L1Fetcher,
 	blobsSrc derive.L1BlobsFetcher, altDASrc driver.AltDAIface,
 	eng L2API, cfg *rollup.Config, syncCfg *sync.Config, safeHeadListener safeDB,
-	interopBackend interop.InteropBackend) *L2Verifier {
+	interopBackend interop.InteropBackend,
+) *L2Verifier {
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
 
@@ -162,6 +164,7 @@ func NewL2Verifier(t Testing, log log.Logger, l1 derive.L1Fetcher,
 		log:               log,
 		Eng:               eng,
 		engine:            ec,
+		derivationMetrics: metrics,
 		derivation:        pipeline,
 		safeHeadListener:  safeHeadListener,
 		syncCfg:           syncCfg,
@@ -238,6 +241,10 @@ func (s *l2VerifierBackend) OnUnsafeL2Payload(ctx context.Context, envelope *eth
 	return nil
 }
 
+func (s *L2Verifier) DerivationMetricsTracer() *testutils.TestDerivationMetrics {
+	return s.derivationMetrics
+}
+
 func (s *L2Verifier) L2Finalized() eth.L2BlockRef {
 	return s.engine.Finalized()
 }

op-e2e/actions/proofs/channel_timeout_test.go

@@ -17,6 +17,11 @@ func runChannelTimeoutTest(gt *testing.T, testCfg *helpers.TestCfg[any]) {
 	env := helpers.NewL2FaultProofEnv(t, testCfg, tp, helpers.NewBatcherCfg())
 	channelTimeout := env.Sd.ChainSpec.ChannelTimeout(0)
 
+	var timedOutChannels uint
+	env.Sequencer.DerivationMetricsTracer().FnRecordChannelTimedOut = func() {
+		timedOutChannels++
+	}
+
 	const NumL2Blocks = 10
 
 	// Build NumL2Blocks empty blocks on L2
@@ -62,6 +67,9 @@ func runChannelTimeoutTest(gt *testing.T, testCfg *helpers.TestCfg[any]) {
 	l2SafeHead = env.Engine.L2Chain().CurrentSafeBlock()
 	require.Equal(t, uint64(0), l2SafeHead.Number.Uint64())
 
+	// Ensure that the channel was timed out.
+	require.EqualValues(t, 1, timedOutChannels)
+
 	// Instruct the batcher to submit the blocks to L1 in a new channel,
 	// submitted across 2 transactions.
 	for i := 0; i < 2; i++ {
@@ -103,6 +111,11 @@ func runChannelTimeoutTest_CloseChannelLate(gt *testing.T, testCfg *helpers.Test
 	env := helpers.NewL2FaultProofEnv(t, testCfg, tp, helpers.NewBatcherCfg())
 	channelTimeout := env.Sd.ChainSpec.ChannelTimeout(0)
 
+	var timedOutChannels uint
+	env.Sequencer.DerivationMetricsTracer().FnRecordChannelTimedOut = func() {
+		timedOutChannels++
+	}
+
 	const NumL2Blocks = 10
 
 	// Build NumL2Blocks empty blocks on L2
@@ -148,6 +161,9 @@ func runChannelTimeoutTest_CloseChannelLate(gt *testing.T, testCfg *helpers.Test
 	l2SafeHead = env.Engine.L2Chain().CurrentSafeBlock()
 	require.Equal(t, uint64(0), l2SafeHead.Number.Uint64())
 
+	// Ensure that the channel was timed out.
+	require.EqualValues(t, 1, timedOutChannels)
+
 	// Cache the second and final frame of the channel from the batcher, but do not submit it yet.
 	for i := 0; i < NumL2Blocks/2; i++ {
 		env.Batcher.ActL2BatchBuffer(t)

op-service/testutils/metrics.go

@@ -14,6 +14,7 @@ type TestDerivationMetrics struct {
 	FnRecordL2Ref             func(name string, ref eth.L2BlockRef)
 	FnRecordUnsafePayloads    func(length uint64, memSize uint64, next eth.BlockID)
 	FnRecordChannelInputBytes func(inputCompressedBytes int)
+	FnRecordChannelTimedOut   func()
 }
 
 func (t *TestDerivationMetrics) CountSequencedTxs(count int) {
@@ -59,6 +60,9 @@ func (t *TestDerivationMetrics) RecordHeadChannelOpened() {
 }
 
 func (t *TestDerivationMetrics) RecordChannelTimedOut() {
+	if t.FnRecordChannelTimedOut != nil {
+		t.FnRecordChannelTimedOut()
+	}
 }
 
 func (t *TestDerivationMetrics) RecordFrame() {