eslint-prettier-typescript

This repo contains an example configuration for using eslint alongside prettier in a TypeScript project.

ESLint has announced they are deprecating all formatting rules in v8.53.0 (November 3, 2023) and will remove them in a later version (likely v10.0.0).

This means that if you want to continue using ESLint for linting and also formatting, you will need to use a plugin like eslint-plugin-prettier to run Prettier as an ESLint rule.

Instead, this repo opts to use ESLint for linting and Prettier for formatting. This is a common approach and is recommended by Prettier themselves. Until ESLint removes their formatting rules, we must use eslint-config-prettier to disable ESLint formatting rules that conflict with prettier.

Installing the Prerequisites

$ npm i -D eslint prettier eslint-config-prettier

Make sure your configuration has extends: ["prettier"] in your ESLint config (it should be the last item in the extends list so it can override other plugin rules).

If you're using TypeScript:

$ npm i -D typescript @typescript-eslint/eslint-plugin

Set your ESLint parser to @typescript-eslint/parser and add "plugin:@typescript-eslint/recommended" to extends (before "prettier") if you want a solid baseline of TS rules.

Configure VSCode to run eslint --fix and prettier on save

// settings.json
{
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": true,
  },
  "[typescript]": {
    "editor.defaultFormatter": "esbenp.prettier-vscode",
    "editor.formatOnSave": true
  }
}

(optional) Install husky and lint-staged to run eslint --fix and prettier on commit

It's recommended to enforce linter and formatter rules on commit. This ensures that all code, even if it was added by a contributor who doesn't have the same configuration, is linted and formatted before being committed.

For the same reason, these checks should also be done in CI. Contributors can also bypass commit hooks by using git commit --no-verify, so CI is the last line of defense.

Reference Article

Install and Initialize husky

$ npx husky-init && npm i

Install lint-staged

$ npm i -D lint-staged

Update .husky/pre-commit

Inside .husky/pre-commit replace npm test with npx lint-staged. Your file should look as follows:

#!/bin/sh
. "$(dirname "$0")/_/husky.sh"
npx lint-staged

Configure lint-staged

{
  "*.{js,ts,tsx}": ["eslint --fix", "prettier --write"]
}