Rig.TUnit.Grpc 0.1.0-beta.2

Rig.TUnit.Grpc

In-process gRPC test host, client factory, and error-metadata helpers for Grpc.AspNetCore services.

What this package is

A WebApplicationFactory-style host that spins up your gRPC service in the same process as the test, so calls skip the network stack entirely while still exercising the full MVC pipeline (authentication, interceptors, problem-details translation). The GrpcTestHost owns the TestServer, wires a gRPC channel over the HttpMessageHandler, and exposes strongly-typed clients for every service you register.

The helpers also include an RpcException inspector that unpacks the binary problem-details-bin metadata key Microsoft's error-handling middleware emits, so assertions can target ProblemDetails.Status, Detail, and Type directly.

When to use it

• Testing a gRPC-first service (command side, query side, gateway).
• Verifying authentication policies behave correctly over gRPC.
• Asserting on structured error responses (RpcException + problem-details).
• Not for: testing the external HTTP/2 surface — use an integration test with a real port for that.

Prerequisites

• .NET 10 SDK
• Project under test references Grpc.AspNetCore.

Quick start

using Rig.TUnit.Grpc.Builder;
using Rig.TUnit.Core.Builder;
using Rig.TUnit.Core.Helpers;

var rig = new RigBuilder()
 .WithIsolation(IsolationKey.FromExecutionContext())
 .UseGrpc(cfg => cfg.ConfigureServices(s => s.AddLogging()))
 .Build();

await using var _ = rig;

Options

Fixture + helper APIs

• Rig.TUnit.Grpc.Builder.GrpcRigBuilder — CRTP builder
• Rig.TUnit.Grpc.Helpers.GrpcTestHost — in-process host + channel
• Rig.TUnit.Grpc.Helpers.ProblemDetailsAssert — unpack problem-details-bin

Per-test isolation

Every GrpcTestHost runs in its own TestServer; the channel's base URI includes the IsolationKey so traces and logs segregate cleanly. Services registered with DI are fresh per test.

Parallelism + performance

• Host startup: ~40 ms (cached assembly scan amortises after first test).
• Per-call overhead: ~200 µs (in-memory pipe — no TCP round-trip).
• Safe under full test parallelism — each test owns its TestServer.

Troubleshooting

• Grpc.Core.RpcException: Status(StatusCode="Internal") — inspect ex.Trailers for problem-details-bin; ProblemDetailsAssert.From(ex) does this for you.
• Host startup slow — first test in a session pays for gRPC reflection assembly scan; subsequent tests reuse the cached result.

See .

Provider quirks + edge cases

• RpcException.Trailers is empty until the call completes — probe it inside the catch branch, not during streaming.
• gRPC's exception translation interceptor (ApplicationExceptionInterceptor) serialises IProblemDetailsProvider-typed exceptions into binary metadata — non-typed exceptions become generic Internal status codes.

Benchmarks

See ; baseline in benchmarks/baseline-005.json.

Related docs

License

MIT. See .