# Gateway Testing

Gateway tests run without installed MXAccess by using fake workers, fake
transports, and in-process gRPC service fakes. Live MXAccess verification belongs
in opt-in integration tests because it depends on installed COM components and
provider state.

## Fake Worker Harness

`FakeWorkerHarness` in `src/MxGateway.Tests/Gateway/Workers/Fakes/` provides an
in-process worker side for named-pipe IPC tests. It uses the same
`WorkerFrameReader`, `WorkerFrameWriter`, and `WorkerEnvelope` contract as the
gateway so tests exercise real frame validation and worker-client state changes.

Use the harness when a gateway or session test needs worker behavior without
starting `MxGateway.Worker.exe` or loading MXAccess COM. The harness scripts:

- `WorkerHello` and `WorkerReady` startup,
- command replies with matching correlation ids,
- ordered `WorkerEvent` frames,
- `WorkerHeartbeat` frames,
- `WorkerFault` frames,
- shutdown acknowledgements,
- malformed protobuf payloads and oversized frame headers,
- slow or hung workers by withholding a reply.

Session-level tests can connect the harness to the pipe created by
`SessionWorkerClientFactory` with `ConnectToGatewayPipeAsync`. Lower-level
`WorkerClient` tests can use `CreateConnectedPairAsync` to create both pipe ends
inside the test.

`GatewayEndToEndFakeWorkerSmokeTests` composes the real gRPC service,
`SessionManager`, `SessionWorkerClientFactory`, `WorkerClient`, and
`EventStreamService` with a scripted fake worker launcher. The smoke test covers
`OpenSession`, `Register`, `AddItem`, `Advise`, one streamed `OnDataChange`
event, and `CloseSession` without loading MXAccess COM.

## Live MXAccess Smoke

`WorkerLiveMxAccessSmokeTests` in `src/MxGateway.IntegrationTests/` composes the
real gRPC service, `SessionManager`, `SessionWorkerClientFactory`,
`WorkerClient`, `WorkerProcessLauncher`, and `MxGateway.Worker.exe`. It is
skipped unless `MXGATEWAY_RUN_LIVE_MXACCESS_TESTS=1` is set because it creates
the installed MXAccess COM object and depends on live provider state.

The live smoke opens a gateway session, launches the x86 worker, runs
`Register`, `AddItem`, and `Advise`, waits a bounded time for one
`OnDataChange`, and closes the session in a `finally` block so the worker gets a
graceful shutdown request even when a command or event assertion fails.

Build the worker before running the smoke:

```bash
dotnet build src/MxGateway.Worker/MxGateway.Worker.csproj -p:Platform=x86
```

Run the smoke explicitly:

```bash
$env:MXGATEWAY_RUN_LIVE_MXACCESS_TESTS = "1"
dotnet test src/MxGateway.IntegrationTests/MxGateway.IntegrationTests.csproj --filter FullyQualifiedName~WorkerLiveMxAccessSmokeTests
```

Optional live smoke variables:

| Variable | Default | Description |
|----------|---------|-------------|
| `MXGATEWAY_LIVE_MXACCESS_WORKER_EXE` | First existing `MxGateway.Worker.exe` under `src/MxGateway.Worker/bin/...` | Worker executable path. Set this when running against a packaged worker or a non-default build output. |
| `MXGATEWAY_LIVE_MXACCESS_ITEM` | `TestChildObject.TestInt` | MXAccess item reference used by `AddItem`. |
| `MXGATEWAY_LIVE_MXACCESS_CLIENT_NAME` | `MxGateway.IntegrationTests` | Client name passed to `Register`. |
| `MXGATEWAY_LIVE_MXACCESS_EVENT_TIMEOUT_SECONDS` | `15` | Maximum wait for the first `OnDataChange`. |

The test output includes session id, worker process id, command status,
HRESULT/status diagnostics, event sequence and handles, close status, and worker
stdout/stderr lines emitted during the run.

## Focused Commands

Run the cross-language smoke matrix tests after changing the documented client
smoke command list:

```bash
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~CrossLanguageSmokeMatrixTests
```

Run the parity fixture matrix tests after changing the integration parity
scenario list:

```bash
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~ParityFixtureMatrixTests
```

Run the fake worker tests after changing gateway worker IPC, session startup, or
event streaming behavior:

```bash
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~FakeWorkerHarnessTests
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~SessionWorkerClientFactoryFakeWorkerTests
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~GatewayEndToEndFakeWorkerSmokeTests
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj --filter FullyQualifiedName~WorkerClientTests
dotnet test src/MxGateway.Worker.Tests/MxGateway.Worker.Tests.csproj -p:Platform=x86 --filter FullyQualifiedName~WorkerPipeSessionTests
```

Run the gateway test project after shared gateway test infrastructure changes:

```bash
dotnet test src/MxGateway.Tests/MxGateway.Tests.csproj
```

## Related Documentation

- [Cross-Language Smoke Matrix](./CrossLanguageSmokeMatrix.md)
- [Parity Fixture Matrix](./ParityFixtureMatrix.md)
- [Gateway Process Design](./gateway-process-design.md)
- [Worker Frame Protocol](./WorkerFrameProtocol.md)
- [MXAccess Worker Instance Detailed Design](./mxaccess-worker-instance-design.md)