Rig.TUnit.Microservices.Contracts 0.1.0-beta.2

Rig.TUnit.Microservices.Contracts

Pact-style contract-test harness: ContractPact + ContractInteraction + builders that replay consumer expectations against a provider host.

What this package is

A lightweight in-process alternative to Pact.Net. A ContractPact captures the set of HTTP or gRPC interactions a consumer expects; the harness replays them against the provider's actual WebApplicationFactory host and verifies every response matches the expectation. Shipped as a family-level contract (ADR-005) so every microservice in the estate has the same verifier surface.

It does not broker files with a remote Pact Broker — the assumption is that contracts are versioned alongside the consumer code in a shared package.

When to use it

• Provider-side verification: "does my microservice still satisfy what the consumer recorded last week?"
• Consumer-side recording: capture the expected interactions inside a unit test; commit the .contract.json.
• Not for: end-to-end tests where you want a real network between parties — that's an integration test, not a contract test.

Prerequisites

• .NET 10 SDK
• Consumer project has Rig.TUnit.Http for building interactions.

Quick start

using Rig.TUnit.Microservices.Contracts;

var pact = new ContractPact(
    consumer: "orders-web",
    provider: "orders-api",
    interactions: Array.Empty<ContractInteraction>());

// Verify against the running provider fixture.
await pact.VerifyAsync(providerBaseUri: new Uri("http://localhost:5097"));

Options

Fixture + helper APIs

• Rig.TUnit.Microservices.Contracts.ContractPact
• Rig.TUnit.Microservices.Contracts.ContractInteraction
• Rig.TUnit.Microservices.Contracts.Helpers.PactFileReader / PactFileWriter

Per-test isolation

Each ContractPact is a value-type recording; verification runs against the provider-supplied base URI. No shared state.

Parallelism + performance

• Per-interaction replay: ~2-5 ms (in-process HttpClient).
• Safe under full parallelism — each test owns its pact instance.

Troubleshooting

• Verification fails with ExtraField(s) present in response — set StrictMatching = false if the extra field is a deliberate backward- compatible addition.
• ContractInteraction.Request.Body is null after read — call ContractInteraction.ReadBodyAsync() before asserting; the raw stream is read lazily.

See docs/troubleshooting.md.

Provider quirks + edge cases

• JSON comparison is structural (property-set equality), not byte-exact — field ordering is ignored.
• gRPC interactions serialise via Protobuf wire format; message equality is byte-exact because that is what the wire sees.

Benchmarks

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

Related docs

• ADR-005 — family-level contracts
• Architecture diagram
• Glossary

License

MIT. See LICENSE.