Configure ESLint and Prettier

Commit

chore: configure ESLint and Prettier

Commands

npm install --save-dev eslint prettier \
  @typescript-eslint/parser @typescript-eslint/eslint-plugin \
  eslint-config-prettier

Update your package.json to enable ECMAScript modules:

{
  "type": "module",
  ...
}

Create ESLint config (ESLint v9+ compatible)

📄 eslint.config.js

import eslintPluginTs from "@typescript-eslint/eslint-plugin";
import parserTs from "@typescript-eslint/parser";
import prettier from "eslint-config-prettier";

export default [
  {
    files: ["**/*.ts"],
    languageOptions: {
      parser: parserTs
    },
    plugins: {
      "@typescript-eslint": eslintPluginTs
    },
    rules: {
      ...eslintPluginTs.configs.recommended.rules,
      "@typescript-eslint/no-unused-vars": ["warn", { argsIgnorePattern: "^_" }]
    },
    ignores: ["dist/**", "node_modules/**"]
  },
  prettier
];

Create Prettier config

📄 .prettierrc

{
  "semi": true,
  "singleQuote": false,
  "tabWidth": 2,
  "printWidth": 80,
  "trailingComma": "es5"
}

Update `package.json` scripts

"scripts": {
  "lint": "eslint 'src/**/*.ts'",
  "format": "prettier --write 'src/**/*.ts'"
}

Verification

Run ESLint

npm run lint

Run Prettier

npm run format

Optional: enable auto-formatting in VS Code 📄 .vscode/settings.json

{
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "source.fixAll": true,
    "source.fixAll.eslint": true
  },
  "eslint.validate": ["typescript"]
}