@energise/style-guide

javascript-style-guide

Introduction

This repository is the home of Energise's style guide, which includes configs for popular linting and style tools.

The following configs are available, and are designed to be used together:

• Prettier
• ESLint
• TypeScript

Installation

All of our configs are contained in one package, @energise/style-guide. To install:

# If you use pnpm
pnpm add -D @energise/style-guide

# If you use npm
npm install -D @energise/style-guide

# If you use yarn
yarn add -D @energise/style-guide

Prettier

Note: Prettier is a peer-dependency of this package, and should be installed at the root of your project.

See: https://prettier.io/docs/en/install.html

To use the shared Prettier config, set the following in package.json:

{
  "prettier": "@energise/style-guide/prettier"
}

ESLint

Note: ESLint is a peer-dependency of this package, and should be installed at the root of your project.

This ESLint config is designed to be composable.

The following base configs are available. You can use one or both of these configs, but they should always be first in extends:

• @energise/style-guide/browser
• @energise/style-guide/node

Note that you can scope configs, so that configs only target specific files. For more information, see: Scoped configuration with overrides.

The following additional configs are available:

• @energise/style-guide/eslint/next (requires @next/eslint-plugin-next to be installed at the same version as next)
• @energise/style-guide/eslint/playwright-test
• @energise/style-guide/eslint/react
• @energise/style-guide/eslint/storybook
• @energise/style-guide/eslint/typescript (requires typescript to be installed and additional configuration)
• @energise/style-guide/eslint/vitest

You'll need to use require.resolve to provide ESLint with absolute paths, due to an issue around ESLint config resolution (see eslint/eslint#9188)

For example, to use the shared ESLint config(s) in a Next.js project, set the following in .eslintrc.cjs:

module.exports = {
  extends: [
    require.resolve('@energise/style-guide/eslint/browser'),
    require.resolve('@energise/style-guide/eslint/react'),
    require.resolve('@energise/style-guide/eslint/next'),
  ],
};

Configuring ESLint for TypeScript

Some of the rules enabled in the TypeScript config require additional type information, you'll need to provide the path to your tsconfig.json.

For more information, see: https://typescript-eslint.io/docs/linting/type-linting

const { resolve } = require('node:path');

const project = resolve(__dirname, 'tsconfig.json');

module.exports = {
  root: true,
  extends: [
    require.resolve('@energise/style-guide/eslint/node'),
    require.resolve('@energise/style-guide/eslint/typescript'),
  ],
  parserOptions: {
    project,
  },
  settings: {
    'import/resolver': {
      typescript: {
        project.
      },
    },
  },
};

Configuring custom components for jsx-a11y

It's common practice for React apps to have shared components like Button, which wrap native elements. You can pass this information along to jsx-a11y via the components setting.

The below list is not exhaustive.

module.exports = {
  root: true,
  extends: [require.resolve('@energise/style-guide/eslint/react')],
  settings: {
    'jsx-a11y': {
      components: {
        Article: 'article',
        Button: 'button',
        Image: 'img',
        Input: 'input',
        Link: 'a',
        Video: 'video',
      },
    },
  },
};

Scoped configuration with overrides

ESLint configs can be scoped to include/exclude specific paths. This ensures that rules don't leak into places where those rules don't apply.

In this example, Vitest rules are only being applied to files matching Vitest's default test match pattern.

module.exports = {
  extends: [require.resolve('@energise/style-guide/eslint/node')],
  overrides: [
    {
      files: [],
      extends: [require.resolve('@energise/style-guide/eslint/vitest')],
    },
  ],
};

A note on file extensions

By default, all TypeScript rules are scoped to files ending with .ts and .tsx.

However, when using overrides, file extensions must be included or ESLint will only include .js files.

module.exports = {
  overrides: [
    {
      files: [`directory/**/*.[jt]s?(x)`, rules: { my-rule: 'off' }],
    },
  ],
};

TypeScript

The following configs are available:

• @energise/style-guide/tsconfig/base
• @energise/style-guide/tsconfig/cloudflare
• @energise/style-guide/tsconfig/next

For example, to use the next TypeScript config in a Next.js project, set the following in tsconfig.json:

{
  "extends": "@energise/style-guide/tsconfig/next"
}

Acknowledgements

• @vercel's style guide