feat: complete remaining jetstream parity implementation plan

tests/NATS.Server.Tests/JetStreamApiFixture.cs

@@ -63,6 +63,13 @@ internal sealed class JetStreamApiFixture : IAsyncDisposable
         return fixture;
     }
 
+    public static async Task<JetStreamApiFixture> StartWithAckAllConsumerAsync()
+    {
+        var fixture = await StartWithStreamAsync("ORDERS", "orders.*");
+        _ = await fixture.CreateConsumerAsync("ORDERS", "ACKALL", "orders.created", ackPolicy: AckPolicy.All);
+        return fixture;
+    }
+
     public static async Task<JetStreamApiFixture> StartWithMirrorSetupAsync()
     {
         var fixture = await StartWithStreamAsync("ORDERS", "orders.*");
@@ -111,6 +118,16 @@ internal sealed class JetStreamApiFixture : IAsyncDisposable
         return PublishAndGetAckAsync(subject, payload);
     }
 
+    public Task<PubAck> PublishWithExpectedLastSeqAsync(string subject, string payload, ulong expectedLastSeq)
+    {
+        if (_publisher.TryCaptureWithOptions(subject, Encoding.UTF8.GetBytes(payload), new PublishOptions { ExpectedLastSeq = expectedLastSeq }, out var ack))
+        {
+            return Task.FromResult(ack);
+        }
+
+        return Task.FromResult(new PubAck { ErrorCode = 404 });
+    }
+
     public Task<JetStreamApiResponse> RequestLocalAsync(string subject, string payload)
     {
         return Task.FromResult(_router.Route(subject, Encoding.UTF8.GetBytes(payload)));
@@ -148,6 +165,15 @@ internal sealed class JetStreamApiFixture : IAsyncDisposable
         return _consumerManager.FetchAsync(stream, durableName, batch, _streamManager, default).AsTask();
     }
 
+    public Task<PullFetchBatch> FetchWithNoWaitAsync(string stream, string durableName, int batch)
+    {
+        return _consumerManager.FetchAsync(stream, durableName, new PullFetchRequest
+        {
+            Batch = batch,
+            NoWait = true,
+        }, _streamManager, default).AsTask();
+    }
+
     public async Task<PullFetchBatch> FetchAfterDelayAsync(string stream, string durableName, int delayMs, int batch)
     {
         await Task.Delay(delayMs);
@@ -174,5 +200,22 @@ internal sealed class JetStreamApiFixture : IAsyncDisposable
         }
     }
 
+    public async Task PublishManyAsync(string subject, IReadOnlyList<string> payloads)
+    {
+        foreach (var payload in payloads)
+            _ = await PublishAndGetAckAsync(subject, payload);
+    }
+
+    public Task AckAllAsync(string stream, string durableName, ulong sequence)
+    {
+        _consumerManager.AckAll(stream, durableName, sequence);
+        return Task.CompletedTask;
+    }
+
+    public Task<int> GetPendingCountAsync(string stream, string durableName)
+    {
+        return Task.FromResult(_consumerManager.GetPendingCount(stream, durableName));
+    }
+
     public ValueTask DisposeAsync() => ValueTask.CompletedTask;
 }