sys_test: add test for eth_syncing

arbnode/transaction_streamer.go

@@ -1066,8 +1066,9 @@ func (s *TransactionStreamer) ResultAtCount(count arbutil.MessageIndex) (*execut
 	return s.exec.ResultAtPos(count - 1)
 }
 
+// exposed for testing
 // return value: true if should be called again immediately
-func (s *TransactionStreamer) executeNextMsg(ctx context.Context, exec execution.ExecutionSequencer) bool {
+func (s *TransactionStreamer) ExecuteNextMsg(ctx context.Context, exec execution.ExecutionSequencer) bool {
 	if ctx.Err() != nil {
 		return false
 	}
@@ -1117,7 +1118,7 @@ func (s *TransactionStreamer) executeNextMsg(ctx context.Context, exec execution
 }
 
 func (s *TransactionStreamer) executeMessages(ctx context.Context, ignored struct{}) time.Duration {
-	if s.executeNextMsg(ctx, s.exec) {
+	if s.ExecuteNextMsg(ctx, s.exec) {
 		return 0
 	}
 	return s.config().ExecuteMessageLoopDelay

system_tests/eth_sync_test.go

@@ -0,0 +1,81 @@
+package arbtest
+
+import (
+	"context"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+func TestEthSyncing(t *testing.T) {
+	t.Parallel()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	builder := NewNodeBuilder(ctx).DefaultConfig(t, true)
+	builder.L2Info = nil
+	cleanup := builder.Build(t)
+	defer cleanup()
+
+	testClientB, cleanupB := builder.Build2ndNode(t, &SecondNodeParams{})
+	defer cleanupB()
+
+	// stop txstreamer so it won't feed execution messages
+	testClientB.ConsensusNode.TxStreamer.StopAndWait()
+
+	countBefore, err := testClientB.ConsensusNode.TxStreamer.GetMessageCount()
+	Require(t, err)
+
+	builder.L2Info.GenerateAccount("User2")
+
+	tx := builder.L2Info.PrepareTx("Owner", "User2", builder.L2Info.TransferGas, big.NewInt(1e12), nil)
+
+	err = builder.L2.Client.SendTransaction(ctx, tx)
+	Require(t, err)
+
+	_, err = builder.L2.EnsureTxSucceeded(tx)
+	Require(t, err)
+
+	// give the inbox reader a bit of time to pick up the delayed message
+	time.Sleep(time.Millisecond * 100)
+
+	// sending l1 messages creates l1 blocks.. make enough to get that delayed inbox message in
+	for i := 0; i < 30; i++ {
+		builder.L1.SendWaitTestTransactions(t, []*types.Transaction{
+			builder.L1Info.PrepareTx("Faucet", "User", 30000, big.NewInt(1e12), nil),
+		})
+	}
+
+	attempt := 0
+	for {
+		if attempt > 30 {
+			Fatal(t, "2nd node didn't get tx on time")
+		}
+		Require(t, ctx.Err())
+		countAfter, err := testClientB.ConsensusNode.TxStreamer.GetMessageCount()
+		Require(t, err)
+		if countAfter > countBefore {
+			break
+		}
+		select {
+		case <-time.After(time.Millisecond * 100):
+		case <-ctx.Done():
+		}
+		attempt++
+	}
+
+	progress, err := testClientB.Client.SyncProgress(ctx)
+	Require(t, err)
+	if progress == nil {
+		Fatal(t, "eth_syncing returned nil but shouldn't have")
+	}
+	for testClientB.ConsensusNode.TxStreamer.ExecuteNextMsg(ctx, testClientB.ExecNode) {
+	}
+	progress, err = testClientB.Client.SyncProgress(ctx)
+	Require(t, err)
+	if progress != nil {
+		Fatal(t, "eth_syncing did not return nil but should have")
+	}
+}