vitest-evals

vitest-evals

Use the harness-backed API as the only authoring model.

First Steps

1. Read the package, app, or eval file being changed.
2. Identify the runtime target, then open only the needed reference.
3. Keep suites close to Vitest: one harness per describeEval(...), explicit run(...) inside each test, ordinary expect(...) assertions over the returned result.

Reference Router

Runtime Defaults

• Import describeEval(...), judges, and helpers from vitest-evals.
• Bind exactly one harness to a suite.
• Call run(input) where the test should execute the system.
• Assert on result.output for app-facing behavior.
• Use toolCalls(result) and message helpers for normalized session assertions.
• Use spans(result), spansByKind(result, kind), and failedSpans(result) for span assertions.
• Keep HarnessRun, NormalizedSession, usage, artifacts, and tool records JSON-serializable.
• Keep judge model calls on judges. Use createJudge("Name", assess) for custom judges; use the provider-helper overload only when multiple judges reuse setup and need curried run options.
• Put scenario-owned criteria on the input value. Put direct-check expected values in Vitest case rows. Pass per-case judge criteria through explicit matcher options, and suite-wide criteria through judge config.
• Custom judges should use createJudge(...) for stable reporter labels.

Verification

Prefer the smallest command that covers the edited files: