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Tautest v1.0.0

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@canblmz1 canblmz1 released this 10 May 23:06
· 83 commits to main since this release
v1.0.0
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Tautest v1.0.0

What is Tautest?

Tautest is a PR-focused mutation testing workflow layer powered by StrykerJS.

It reads changed source lines from a Git diff, runs StrykerJS mutation testing on that focused scope, turns surviving mutants into readable reports, and generates deterministic test-fix prompts for AI coding agents such as Claude Code, Cursor, and Codex.

Tautest is not a mutation engine. StrykerJS performs the mutation testing.

Highlights

  • Changed-line mutation scoping from git diff.
  • Vitest-first workflow.
  • Jest beta support.
  • Markdown, JSON, and terminal reports.
  • Deterministic AI fix prompt generation.
  • GitHub Action with sticky PR comments.
  • .tautest artifact upload.
  • Incremental cache handling for StrykerJS reports.
  • Example projects for Vitest, Vitest React, and Jest beta.

Install

Vitest:

pnpm add -D tautest @stryker-mutator/core @stryker-mutator/vitest-runner
pnpm exec tautest init --yes --runner vitest --no-install
pnpm exec tautest doctor
pnpm exec tautest run --base origin/main

Jest beta:

pnpm add -D tautest @stryker-mutator/core @stryker-mutator/jest-runner
pnpm exec tautest init --yes --runner jest --no-install

CLI check:

npx tautest@latest --help

GitHub Action usage

After the v1 tag is created, use the monorepo action path:

name: Tautest

on:
  pull_request:

permissions:
  contents: read
  pull-requests: write

jobs:
  tautest:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: actions/setup-node@v4
        with:
          node-version: 20

      - uses: pnpm/action-setup@v4
        with:
          version: 10

      - run: pnpm install --frozen-lockfile
      - run: pnpm build

      - uses: canblmz1/tautest/packages/github-action@v1
        with:
          base: ${{ github.base_ref }}
          threshold: 60
          comment: changes
          cache: true

Important notes:

  • fetch-depth: 0 is required for reliable Git diff behavior.
  • pull-requests: write is required for sticky PR comments.

Validation before release

  • Local typecheck, lint, test, build, and production audit passed.
  • npm package versions verified:
    • tautest@1.0.0
    • @tautest/core@1.0.0
  • Main branch Release Readiness workflow passed.
  • Source-changing PR smoke passed.
  • Mutation run completed and JSON output parsed in GitHub Actions.
  • Sticky PR comment create/update verified.
  • Artifact upload verified.
  • Same-repository PR permissions verified.

Known limitations

  • Tautest uses StrykerJS; it is not a mutation engine.
  • Jest support is beta.
  • Monorepo support is detect-and-warn level in v1.
  • Runtime depends on project size and test speed.
  • Vitest browser mode and unusual runner setups may need manual StrykerJS config.
  • GitHub PR comments depend on repository token permissions.
  • Cache handling is graceful, but a real cache hit was not proven in the v1 source PR smoke.

Next roadmap

  • Harden Jest beta with more fixtures.
  • Improve monorepo package selection.
  • Add richer ESM/CJS and path alias recipes.
  • Improve GitHub Action cache observability.
  • Migrate the GitHub Action runtime from Node 20 to Node 24 after validation.
  • Explore richer review-tool and IDE integrations.
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