@transferwise/eslint-config

:shirt: TransferWise ESLint config with Prettier

This is an extensible ESLint config used at TransferWise :money_with_wings:

It uses Airbnb's as a base, has Prettier baked in, and overrides some rules we've seen ourselves having to change often :heart:

Usage

1. Install with peer dependencies

npx install-peerdeps --dev @transferwise/eslint-config

(if it doesn't work, update npm)

2. Extend your config with @transferwise

.eslintrc

{
  "extends": "@transferwise"
}

Your own config can extend and override it however you want. If you find yourself changing a certain rule often, consider contributing.

3. Lint and format

It's recommended to:

• lint as part of the npm test script (f.e. eslint src/)
• auto-format on save in your editor/IDE (nothing specific to this config, just install ESLint for your tool)
• add auto-formatting before committing:

package.json

{
  ...,
  "lint-staged": {
    "*.js": [
      "eslint --fix",
      "git add"
    ]
  },
  "husky": {
    "hooks": {
      "pre-commit": "lint-staged"
    }
  }
}

lint-staged and husky are already installed for you as part of this package's peer dependencies :ok_hand:

4. [Optional] Set up Prettier to use our base configuration

As of version 1.17 Prettier supports shared config files. :tada:

To use the configuration provided by this package, add the following line to your package.json:

package.json

{
  ...,
  "prettier": "@transferwise/eslint-config/.prettierrc.js"
}

Read more about shared configs especially, if you need to extend/override the default configuration.

This is only required if you're running Prettier as a file watcher in your IDE to automatically format files. JS files will be formatted by eslint even if you don't configure your IDE.

Contributing

If you think a rule should be added or changed, create a pull request. The change will be discussed, and if people agree, it can be merged. Every merge automatically releases to GitHub and npm.

Bear in mind that you'll need to bump the version in package.json (major for breaking rules, minor for additions, patch for bugfixes) and add a CHANGELOG.md entry.