test(localdb): pin drift-watermark branch; guard writer loop against completed-lane spin

2026-07-17 22:50:33 -04:00
parent 92ccbac8db
commit 183901e8ac
2 changed files with 105 additions and 6 deletions
@@ -145,6 +145,12 @@ public sealed class SyncSessionTests : IDisposable
        return r[0];
    }

+    private static async Task<long> LastAppliedRemoteSeq(SqliteLocalDb db)
+    {
+        var r = await db.QueryAsync("SELECT last_applied_remote_seq FROM __localdb_peer_state WHERE id = 1", x => x.GetInt64(0));
+        return r[0];
+    }
+
    private static OplogEntry ProtoEntry(long seq, long id, string sku, long hlc, string nodeId = "peer") =>
        new()
        {
@@ -461,6 +467,82 @@ public sealed class SyncSessionTests : IDisposable
        await SwallowAsync(run);
    }

+    [Fact]
+    public async Task TopSeqDrifted_WatermarkStillAdvances()
+    {
+        // The batch's TOP seq is dead-lettered, so the applier's watermark stops below it; the
+        // session's standalone MAX update must still advance the durable watermark and the ack.
+        var a = await NewSideAsync(
+            options: new ReplicationOptions { FlushInterval = TimeSpan.FromMilliseconds(20), FailClosedOnDrift = true });
+        var (duplex, toSession, fromSession) = ScriptedPeer();
+
+        using var cts = new CancellationTokenSource(RunTimeout);
+        var run = a.Session.RunAsync(duplex, cts.Token);
+
+        await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
+
+        await toSession.WriteAsync(new SyncMessage
+        {
+            DeltaBatch = new DeltaBatch
+            {
+                Entries =
+                {
+                    ProtoEntry(1, 1, "CLEAN", 5_000_000),
+                    ProtoEntry(2, 2, "DRIFTED", AheadHlc(TimeSpan.FromMinutes(10))),
+                },
+            },
+        }, cts.Token);
+        var ack = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
+
+        Assert.Equal(2, ack.DeltaAck.AppliedThruSeq);
+        Assert.Equal(2, await LastAppliedRemoteSeq(a.Db));
+        var rows = await ReadOrders(a.Db);
+        Assert.Single(rows);
+        Assert.Equal(1, rows[0].Id);
+        var dead = await a.Db.QueryAsync("SELECT pk_json FROM __localdb_dead_letter", x => x.GetString(0));
+        Assert.Equal(["{\"id\":2}"], dead);
+
+        cts.Cancel();
+        await SwallowAsync(run);
+    }
+
+    [Fact]
+    public async Task AllEntriesDrifted_WatermarkStillAdvances()
+    {
+        // Every entry dead-lettered: the applier sees an empty batch (AppliedThruSeq 0), yet the
+        // durable watermark and the ack must still cover the batch's max seq.
+        var a = await NewSideAsync(
+            options: new ReplicationOptions { FlushInterval = TimeSpan.FromMilliseconds(20), FailClosedOnDrift = true });
+        var (duplex, toSession, fromSession) = ScriptedPeer();
+
+        using var cts = new CancellationTokenSource(RunTimeout);
+        var run = a.Session.RunAsync(duplex, cts.Token);
+
+        await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
+
+        await toSession.WriteAsync(new SyncMessage
+        {
+            DeltaBatch = new DeltaBatch
+            {
+                Entries =
+                {
+                    ProtoEntry(1, 1, "DRIFTED1", AheadHlc(TimeSpan.FromMinutes(10))),
+                    ProtoEntry(2, 2, "DRIFTED2", AheadHlc(TimeSpan.FromMinutes(11))),
+                },
+            },
+        }, cts.Token);
+        var ack = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
+
+        Assert.Equal(2, ack.DeltaAck.AppliedThruSeq);
+        Assert.Equal(2, await LastAppliedRemoteSeq(a.Db));
+        Assert.Empty(await ReadOrders(a.Db));
+        var dead = await a.Db.QueryAsync("SELECT pk_json FROM __localdb_dead_letter ORDER BY pk_json", x => x.GetString(0));
+        Assert.Equal(["{\"id\":1}", "{\"id\":2}"], dead);
+
+        cts.Cancel();
+        await SwallowAsync(run);
+    }
+
    [Fact]
    public async Task PeerNeedsSnapshot_InvokesSnapshotHooks()
    {