facebook/jestNew scan
91/ 100 · A

A top-tier open source project. Docs, tests, and CI are all in excellent shape.

Delightful JavaScript Testing.

TypeScript45,444 starsMITupdated 6d ago
DocumentationREADME, setup, examples, license
95
EngineeringTests, CI, linting, lockfiles
96
Project healthDescription, activity, stars, deps
75

What to fix first

The highest-impact improvements for this repo.

  1. 1
    Install and run instructions
    DocumentationInfo

    Add a .env.example listing all required environment variables so contributors know what to set up.

  2. 2
    Reproducibility
    EngineeringInfo

    Add a Dockerfile, .nvmrc, or .python-version to pin the runtime version and make the environment reproducible.

  3. 3
    Reproducibility
    EngineeringInfo

    Add .github/dependabot.yml with at least one package-ecosystem entry so dependencies are updated automatically.

Detailed breakdown

Documentation

95
  • README100
    • README is present.
    • README is well structured with multiple sections.
    • README includes screenshots or visuals. Great for first impressions.
    • README has code examples.
    • README links to a live demo or deployed app.
    • README includes status badges.
  • Install and run instructions90
    • README documents how to install the project.
    • README documents how to run the project.
    • If your project uses environment variables, add a .env.example listing them (+10 pts).Add a .env.example listing all required environment variables so contributors know what to set up.
  • License100
    • Licensed under MIT.
  • Contributing guide83
    • Contributing guide is detailed and thorough.
    • Contributing guide lacks a setup section (−12 pts).Show new contributors how to get a local dev environment running.
    • Contributing guide lacks a code style section (−8 pts).Describe your linting/formatting rules and how to run them (e.g. npm run lint, ruff check .).
    • Contributing guide explains how to run tests.
    • Contributing guide describes the PR/review workflow.
    • Contributing guide includes code examples.
    • Code of conduct present.

Engineering

96
  • Tests100
    • Test files detected (benchmarks/test-file-overhead/0.test.js).
  • CI/CD100

    Not applicable?

    • CI is configured (.github/workflows/check-changelog.yml).
    • CI workflow runs tests.
    • CI runs on pull requests, not just on pushes to main.
    • CI workflow runs a lint or format check.
    • CI runs type checking (tsc, mypy, cargo check, etc.).
    • CI reports or uploads test coverage.
    • CI caches dependencies for faster runs.
    • CI tests across multiple environments or versions.
    • CI includes a build step.
  • Linting and formatting95
    • Linter or formatter configured (.editorconfig).
    • Lint script wired into package.json.
    • tsconfig.json has `strict: true`. Full TypeScript type safety enabled.
  • Reproducibility70
    • Lockfile present (yarn.lock). Installs are reproducible.
    • No Dockerfile or runtime version pin found. Adding one earns +10 pts.Add a Dockerfile, .nvmrc, or .python-version to pin the runtime version and make the environment reproducible.
    • No Dependabot config (adding it earns up to +20 pts).Add .github/dependabot.yml with at least one package-ecosystem entry so dependencies are updated automatically.
  • Issue and PR templates100
    • Issue or PR templates present.
    • Security policy present.

Project health

75
  • Dependency manifest65
    • Dependency manifest found (package.json).
    • package.json is missing a description (−10 pts).Add a one-line description to package.json. It appears in npm search and on GitHub.
    • package.json has no repository field (−10 pts).Add a `repository` field pointing to the GitHub URL so npm knows where the source lives.
    • package.json has no keywords (−8 pts).Add a `keywords` array to help people find your package on npm.
    • package.json has no homepage field (−7 pts).Add a `homepage` field pointing to your docs or project website.
  • Repository metadata70
    • Repository has a description.
    • Primary language detected: TypeScript.
  • Activity100
    • Actively maintained (pushed within the last month).
    • 45,444 stars.
  • Housekeeping60
    • .gitignore present.
    • Build artifacts or local files may be committed (e2e/global-setup-node-modules/node_modules/example) (−40 pts).Remove them and add to .gitignore.
Repository files47 root entries
  • .claude
  • .eslintplugin
  • .github
    Good: CI is configured (.github/workflows/check-changelog.yml).
    Good: Issue or PR templates present.
  • .vscode
  • .yarn
  • benchmarks
    Good: Test files detected (benchmarks/test-file-overhead/0.test.js).
  • docs
  • e2e
    Warning: Build artifacts or local files may be committed (e2e/global-setup-node-modules/node_modules/example) (−40 pts).Fix: Remove them and add to .gitignore.
  • examples
  • packages
  • scripts
  • website
  • .claudeignore
  • .codecov.yml
  • .editorconfig
    Good: Linter or formatter configured (.editorconfig).
  • .gitattributes
  • .gitignore
    Good: .gitignore present.
  • .gitpod.yml
  • .prettierignore
  • .watchmanconfig
  • .yarnrc.yml
  • babel.config.js
  • CHANGELOG_PRE_v30.md
  • CHANGELOG.md
    Good: Contributing guide is detailed and thorough.
    Info: Contributing guide lacks a setup section (−12 pts).Fix: Show new contributors how to get a local dev environment running.
    Info: Contributing guide lacks a code style section (−8 pts).Fix: Describe your linting/formatting rules and how to run them (e.g. npm run lint, ruff check .).
    Good: Contributing guide explains how to run tests.
    Good: Contributing guide describes the PR/review workflow.
    Good: Contributing guide includes code examples.
  • CLAUDE.md
  • CODE_OF_CONDUCT.md
    Good: Code of conduct present.
  • CONTRIBUTING.md
  • crowdin.yaml
  • eslint.config.mjs
  • GOVERNANCE.md
  • jest
  • jest.config.ci.mjs
  • jest.config.mjs
  • jest.config.ts.mjs
  • lerna.json
  • LICENSE
    Good: Licensed under MIT.
  • netlify.toml
  • package.json
    Good: Dependency manifest found (package.json).
  • PROJECT_CHARTER.md
  • README.md
    Good: README is present.
    Good: README is well structured with multiple sections.
    Good: README includes screenshots or visuals. Great for first impressions.
    Good: README has code examples.
    Good: README links to a live demo or deployed app.
    Good: README includes status badges.
    Good: README documents how to install the project.
    Good: README documents how to run the project.
  • SECURITY.md
    Good: Security policy present.
  • tsconfig.json
  • tsconfig.test.json
  • tsconfig.typetest.json
  • tstyche.config.json
  • yarn.config.cjs
  • yarn.lock
    Good: Lockfile present (yarn.lock). Installs are reproducible.