@18f/18f-eslint

18F eslint

This app wraps the eslint configuration described in the TTS engineering practices guide, to make it easier to get started. To use, first install:

npm install @18f/eslint

This will install all the appropriate base configurations, plugins, and prettier. (Since eslint 6, installing these in your local project is recommended, even if you're using a globally-installed eslint or running with npx.) It will also create (or update) a .eslintrc file with the base configuration and add a prettier configuration to your `package.json. (This is primarily to enable code editors to pick it up.)

To run the 18F-configured eslint on your application, you can either use npx, or add it as a script to your package.json. By default, it will lint all files supported by eslint starting at the current directory, but you can also specify paths to lint in the command line arguments:

# Lint all the things
npx @18f/18f-eslint

# Lint some of the things
npx @18f/18f-eslint src

Or in package.json:

{
  ...
  "scripts": {
    "lint": "18f-eslint"
  }
}

Once the script is defined, you can run it with npm run lint.

The command line arguments are passed to the eslint lintFiles method. They can be a combination of file names, directory names, or glob patterns. Note that if you're using globs, they should be wrapped in quotes so that they are not evaluated by the shell.

Configuration

By default, your application will be configured to extend the airbnb and prettier base configurations. It will also enable the es6 environment. If your project uses React, it will also extend the prettier/react configuration and enable the browser environment; otherwise, it will enable the node environment.

All of these configurations can be overridden or extended by your local .eslintrc.* file. The configuration provided by this library is presented to eslint as a base, and your local, project-level configurations will supercede it. By default, it's probably safest not to define an env or extends property in your own config file, but you certainly can if necessary.

If your project is written for ES5 or below, install eslint-config-airbnb-base/legacy) and update your eslintrc file to include it in the extends property.

The script determins whether or not your project project is a React project by finding the nearest package.json and looking for react in either your dependencies or dev-dependencies.

GitHub Action

There is a GitHub Action that makes it easy to add 18F-eslint to your CI/CD pipeline. In addition, this package can configure the action for you:

npx -p @18f/18f-eslint install-action

This will add an 18F-eslint GitHub action to your repo for each package.json file. If you have a monorepo, it should more-or-less just work. It defaults to linting all Javascript files under each path, but you can tweak the workflow to suit your needs. See the documentation for more info about configuration the action.

Under the hood

The 18F eslint wrapper imports our recommended eslint rules and plugins, those specified by the Airbnb JavaScript style guide.

• For all projects
  • eslint-config-prettier
  • prettier
• For React projects:
  • eslint-config-airbnb
  • eslint-plugin-import
  • eslint-plugin-jsx-a11y
  • eslint-plugin-react
• For ES6/2015 projects that don't use React:
  • eslint-config-airbnb-base
  • eslint-plugin-import

Public domain

This project is in the worldwide public domain. As stated in CONTRIBUTING:

This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.

All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.