Rig.TUnit.Observability.Tracing 0.1.0-beta.2

Rig.TUnit.Observability.Tracing

In-memory OpenTelemetry tracing fixture with InMemoryExporter and fluent TraceAssert for span / tag / status / parent-child verification.

What this package is

The tracing counterpart to Rig.TUnit.Observability.Logging. TracingFixture wires a TracerProvider with an InMemoryExporter so every Activity emitted through a known ActivitySource gets captured. TraceAssert is the fluent DSL: .HasSpan(name).WithTag(…).WithStatus (Ok).DurationLessThan(1s).

When to use it

• Integration tests verifying spans are emitted at the right code sites.
• Asserting tag values and status codes on critical-path operations.
• Verifying parent/child relationships across async boundaries.
• Not for: E2E tests against a real OTLP collector.

Prerequisites

• .NET 10 SDK
• OpenTelemetry + .Exporter.InMemory (transitive)

Quick start

using System.Diagnostics;
using Rig.TUnit.Observability.Tracing.Fixtures;
using Rig.TUnit.Observability.Tracing.Options;

await using var fx = new TracingFixture(new TracingFixtureOptions { ServiceName = "my-svc" });
await fx.InitializeAsync();

using (var act = fx.ActivitySource.StartActivity("op.work"))
{
 act?.SetStatus(ActivityStatusCode.Ok);
}

Options

Fixture + helper APIs

• Rig.TUnit.Observability.Tracing.Fixtures.TracingFixture
• Rig.TUnit.Observability.Tracing.Options.TracingFixtureOptions
• Rig.TUnit.Observability.Tracing.Builder.TracingRigBuilder
• Rig.TUnit.Observability.Tracing.Assertions.TraceAssert

Per-test isolation

Each TracingFixture owns its exporter. ServiceName includes IsolationKey so spans stay distinguishable across parallel fixtures.

Parallelism + performance

• Fixture construction: ~3 ms.
• Per-span overhead: ~2 µs (no network).
• Safe under full parallelism.

Troubleshooting

• HasSpan("name") reports not-found — ActivitySource name mismatch. Check fx.ActivitySource.Name matches what the code under test uses.
• Parent-child broken across Task.Run — Activity.Current is AsyncLocal and does cross Task.Run, but a thread-pool worker executed before the Activity started loses context. Instrument with explicit ActivityContext propagation.

See .

Provider quirks + edge cases

• Spans are immutable after Stop — mutation attempts are silently ignored by OTEL SDK.
• InMemoryExporter keeps all spans until fixture disposal; long test runs with millions of spans can OOM. Call fx.Clear() between test phases if needed.
• Span status is Unset by default; promoting to Ok or Error requires an explicit SetStatus call.

Benchmarks

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

Related docs

• Family base:

License

MIT. See .