Add Polly resilience policies

src/MxGateway.Worker.Tests/Ipc/WorkerPipeClientTests.cs

@@ -80,6 +80,65 @@ public sealed class WorkerPipeClientTests
         await clientTask;
     }
 
+    [Fact]
+    public async Task RunAsync_RetriesUntilPipeServerAppears()
+    {
+        string pipeName = $"mxaccess-gateway-test-{Guid.NewGuid():N}";
+        WorkerOptions workerOptions = new(
+            "session-1",
+            pipeName,
+            GatewayContractInfo.WorkerProtocolVersion,
+            "nonce-secret");
+        WorkerFrameProtocolOptions frameOptions = new(workerOptions);
+
+        WorkerPipeClient client = new(
+            logger: null,
+            connectTimeoutMilliseconds: 1000,
+            connectAttemptTimeoutMilliseconds: 50,
+            (stream, options, _) => CreateSession(stream, options));
+        Task clientTask = client.RunAsync(workerOptions);
+
+        await Task.Delay(150);
+
+        using NamedPipeServerStream server = new(
+            pipeName,
+            PipeDirection.InOut,
+            1,
+            PipeTransmissionMode.Byte,
+            PipeOptions.Asynchronous);
+
+        await Task.Factory.FromAsync(server.BeginWaitForConnection, server.EndWaitForConnection, null);
+
+        WorkerFrameReader reader = new(server, frameOptions);
+        WorkerFrameWriter writer = new(server, frameOptions);
+
+        await writer.WriteAsync(CreateGatewayHello());
+        Assert.Equal(WorkerEnvelope.BodyOneofCase.WorkerHello, (await reader.ReadAsync()).BodyCase);
+        Assert.Equal(WorkerEnvelope.BodyOneofCase.WorkerReady, (await reader.ReadAsync()).BodyCase);
+        await writer.WriteAsync(CreateShutdown());
+
+        Assert.Equal(WorkerEnvelope.BodyOneofCase.WorkerShutdownAck, (await reader.ReadAsync()).BodyCase);
+        await clientTask;
+    }
+
+    [Fact]
+    public async Task RunAsync_WhenPipeNeverAppears_ThrowsTimeoutException()
+    {
+        WorkerOptions workerOptions = new(
+            "session-1",
+            $"mxaccess-gateway-test-{Guid.NewGuid():N}",
+            GatewayContractInfo.WorkerProtocolVersion,
+            "nonce-secret");
+
+        WorkerPipeClient client = new(
+            logger: null,
+            connectTimeoutMilliseconds: 100,
+            connectAttemptTimeoutMilliseconds: 50,
+            (stream, options, _) => CreateSession(stream, options));
+
+        await Assert.ThrowsAsync<TimeoutException>(async () => await client.RunAsync(workerOptions));
+    }
+
     private static WorkerPipeSession CreateSession(
         Stream stream,
         WorkerFrameProtocolOptions options)
@@ -97,6 +156,37 @@ public sealed class WorkerPipeClientTests
             () => new FakeRuntimeSession());
     }
 
+    private static WorkerEnvelope CreateGatewayHello()
+    {
+        return new WorkerEnvelope
+        {
+            ProtocolVersion = GatewayContractInfo.WorkerProtocolVersion,
+            SessionId = "session-1",
+            Sequence = 1,
+            GatewayHello = new GatewayHello
+            {
+                SupportedProtocolVersion = GatewayContractInfo.WorkerProtocolVersion,
+                Nonce = "nonce-secret",
+                GatewayVersion = "test-gateway",
+            },
+        };
+    }
+
+    private static WorkerEnvelope CreateShutdown()
+    {
+        return new WorkerEnvelope
+        {
+            ProtocolVersion = GatewayContractInfo.WorkerProtocolVersion,
+            SessionId = "session-1",
+            Sequence = 2,
+            WorkerShutdown = new WorkerShutdown
+            {
+                GracePeriod = Duration.FromTimeSpan(TimeSpan.FromSeconds(1)),
+                Reason = "test-complete",
+            },
+        };
+    }
+
     private sealed class FakeRuntimeSession : IWorkerRuntimeSession
     {
         public Task<WorkerReady> StartAsync(