op-e2e: wait for observed seq reorg in TestMissingBatchE2E

op-e2e/system_test.go

@@ -393,6 +393,9 @@ func TestMissingBatchE2E(t *testing.T) {
 
 	l2Seq := sys.Clients["sequencer"]
 	l2Verif := sys.Clients["verifier"]
+	seqRollupRPCClient, err := rpc.DialContext(context.Background(), sys.RollupNodes["sequencer"].HTTPEndpoint())
+	require.Nil(t, err)
+	seqRollupClient := sources.NewRollupClient(client.NewBaseRPCClient(seqRollupRPCClient))
 
 	// Transactor Account
 	ethPrivKey := cfg.Secrets.Alice
@@ -414,8 +417,8 @@ func TestMissingBatchE2E(t *testing.T) {
 	require.Equal(t, ethereum.NotFound, err, "Found transaction in verifier when it should not have been included")
 
 	// Wait a short time for the L2 reorg to occur on the sequencer as well.
-	// The proper thing to do is to wait until the sequencer marks this block safe.
-	<-time.After(2 * time.Second)
+	err = waitForSafeHead(ctx, receipt.BlockNumber.Uint64(), seqRollupClient)
+	require.Nil(t, err, "timeout waiting for L2 reorg on sequencer safe head")
 
 	// Assert that the reconciliation process did an L2 reorg on the sequencer to remove the invalid block
 	ctx2, cancel := context.WithTimeout(context.Background(), time.Second)