joelhooks/mutant-cafe

选用指南

AI 根据 README 整理 · 2026/11/4 05:12:09

适用场景

适用于在 CI 中检查变更代码的变异测试，可通过 --in-diff-range 和 --max-mutants 控制范围，并生成 GitHub 格式的摘要。

查看 README 依据

## CI Use a git range to check changed bodies and a mutant budget to cap the work. The budget applies after file, diff and function selection. Ordering uses repository-relative file path (lexical, not locale-dependent), start line, column, then id. `--max-mutants 0` keeps none. Budget-skipped mutants are not outcomes. This advisory GitHub Actions job writes a step summary and updates one sticky PR comment. Install mutant-cafe as a dev dependency first. Replace `npm ci` with your package manager's install command if needed; run the mutation command from the package you want to test. ```yaml

name: Mutation advisory on: pull_request permissions: contents: read pull-requests: write jobs: mutants: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 with: fetch-depth: 0 - uses: actions/setup-node@v4 with: node-version: 24 - run: npm ci - name: Check changed bodies run: >- npx --no-install mutant-cafe --in-diff-range "origin/${{ github.base_ref }}...HEAD" --max-mutants 40 --format github --advisory --summary-md mutant-summary.md

使用方式

通过命令行使用，例如使用 npx mutant-cafe --list 预览变异体，使用 --jobs 指定并行任务数。

查看 README 依据

- `Effect.succeed(value)` for plausible values of `A`, `Effect.fail` of each tag, `Effect.die`, and `Effect.never` behind a measured timeout - `Option.none()` and `Option.some(value)` - `Stream.empty`, a one-element stream, and a failing stream - a `Layer` that dies at build, even when its error type is `never`, plus one failing build per error tag - flipped booleans and cycled literal unions ## Use it Needs Node 24 or later, a `tsconfig.json`, and a vitest suite that passes. ```sh npm install -D mutant-cafe npx mutant-cafe --list # preview the mutants

npx mutant-cafe --jobs 4 # test them ``` It mutates internal functions by default, including `Effect.fn` and `Effect.fnUntraced`, object-literal arrows, service methods inside Layers, and the inner function of a curried export. Layer values and static Layer properties are targets too. Names follow their path, such as `Greeter.layer.greet`, `policy.canEdit`, and `guardFor.<inner>`. With `--exported-only`, targets must be reachable through an exported binding path: exported top-level functions, methods and functions in exported values, returned curried functions, and exported Layers with

部署要求

需要 Node 24 或更高版本，以及一个 tsconfig.json 和通过测试的 vitest 套件。

查看 README 依据

- `Effect.succeed(value)` for plausible values of `A`, `Effect.fail` of each tag, `Effect.die`, and `Effect.never` behind a measured timeout - `Option.none()` and `Option.some(value)` - `Stream.empty`, a one-element stream, and a failing stream - a `Layer` that dies at build, even when its error type is `never`, plus one failing build per error tag - flipped booleans and cycled literal unions ## Use it Needs Node 24 or later, a `tsconfig.json`, and a vitest suite that passes. ```sh npm install -D mutant-cafe npx mutant-cafe --list # preview the mutants

已知限制

不支持 node:test，且仅支持 Vitest 作为测试运行器；对于非 Vitest 运行器，结果会被标记为不可靠。

查看 README 依据

This does not add `node:test` support. Literal relative imports are traced transitively; computed imports remain subject to the full-suite fallback. Selection and partial failures come from Vitest's reporter hooks, not its human-readable messages. A reported failure still counts as caught if another test file hangs.

test` are unverified, not declared non-Vitest. Only an explicit non-Vitest runner skips the baseline and makes all results unreliable. Delegated or unknown scripts and failed selection probes warn but do not disable the Vitest baseline.