fix: api: fix EthSubscribe tipsets off by one (filecoin-project#11858)

Eth subscribe tipsets API should only return tipsets that have been executed.

We do this by only returning the parent tipset of the latest tipset received by ETH Subscribe from it's TipSetFilter subscription.

Closes filecoin-project#11807
Subsumes filecoin-project#11816

itests/eth_filter_test.go

@@ -137,6 +137,41 @@ func TestEthNewPendingTransactionFilter(t *testing.T) {
 	}
 }
 
+func TestEthNewHeadsSubSimple(t *testing.T) {
+	require := require.New(t)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	kit.QuietAllLogsExcept("events", "messagepool")
+
+	client, _, ens := kit.EnsembleMinimal(t, kit.MockProofs(), kit.ThroughRPC(), kit.WithEthRPC())
+	ens.InterconnectAll().BeginMining(10 * time.Millisecond)
+
+	// install filter
+	subId, err := client.EthSubscribe(ctx, res.Wrap[jsonrpc.RawParams](json.Marshal(ethtypes.EthSubscribeParams{EventType: "newHeads"})).Assert(require.NoError))
+	require.NoError(err)
+
+	err = client.EthSubRouter.AddSub(ctx, subId, func(ctx context.Context, resp *ethtypes.EthSubscriptionResponse) error {
+		rs := *resp
+		block, ok := rs.Result.(map[string]interface{})
+		require.True(ok)
+		blockNumber, ok := block["number"].(string)
+		require.True(ok)
+
+		blk, err := client.EthGetBlockByNumber(ctx, blockNumber, false)
+		require.NoError(err)
+		require.NotNil(blk)
+		fmt.Printf("block: %v\n", blk)
+		// block hashes should match
+		require.Equal(block["hash"], blk.Hash.String())
+
+		return nil
+	})
+	require.NoError(err)
+	time.Sleep(2 * time.Second)
+}
+
 func TestEthNewPendingTransactionSub(t *testing.T) {
 	require := require.New(t)
 

node/impl/full/eth_events.go

@@ -250,6 +250,8 @@ type ethSubscription struct {
 	sendQueueLen int
 	toSend       *queue.Queue[[]byte]
 	sendCond     chan struct{}
+
+	lastSentTipset *types.TipSetKey
 }
 
 func (e *ethSubscription) addFilter(ctx context.Context, f filter.Filter) {
@@ -337,12 +339,27 @@ func (e *ethSubscription) start(ctx context.Context) {
 					e.send(ctx, r)
 				}
 			case *types.TipSet:
-				ev, err := newEthBlockFromFilecoinTipSet(ctx, vt, true, e.Chain, e.StateAPI)
-				if err != nil {
-					break
+				// Skip processing for tipset at epoch 0 as it has no parent
+				if vt.Height() == 0 {
+					continue
+				}
+				// Check if the parent has already been processed
+				parentTipSetKey := vt.Parents()
+				if e.lastSentTipset != nil && (*e.lastSentTipset) == parentTipSetKey {
+					continue
+				}
+				parentTipSet, loadErr := e.Chain.LoadTipSet(ctx, parentTipSetKey)
+				if loadErr != nil {
+					log.Warnw("failed to load parent tipset", "tipset", parentTipSetKey, "error", loadErr)
+					continue
+				}
+				ethBlock, ethBlockErr := newEthBlockFromFilecoinTipSet(ctx, parentTipSet, true, e.Chain, e.StateAPI)
+				if ethBlockErr != nil {
+					continue
 				}
 
-				e.send(ctx, ev)
+				e.send(ctx, ethBlock)
+				e.lastSentTipset = &parentTipSetKey
 			case *types.SignedMessage: // mpool txid
 				evs, err := ethFilterResultFromMessages([]*types.SignedMessage{vt})
 				if err != nil {