@ncontiero/eslint-config NPM

@ncontiero/eslint-config

Nicolas's ESLint config preset for JavaScript, TypeScript, and Prettier.

Features

Double quotes, with semi.
Format with Prettier.
Sort imports, package.json, tsconfig.json...
Reasonable defaults, best practices, only one line of config.
Designed to work with TypeScript out-of-box.
Support JSON(5), YAML, TOML, Markdown...
ESLint Flat config, compose easily!
Ignores common files like dist, node_modules, coverage, and files in .gitignore.
Optional React, NextJs, TailwindCSS, TanStack Query support.
Requires ESLint v9.20.0+.

Usage

Install the dependencies:

npm i -D eslint @ncontiero/eslint-config

Require Node.js >= 18.18, and ESLint >= 9.20.0.

Create eslint.config.mjs in your project root:

// eslint.config.mjs
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero(
  // Features: it'll detect installed dependency and enable necessary features automatically
  {
    prettier: true,
    markdown: true,
    react: true, // auto detection
    nextjs: false, // auto detection
    tailwindcss: false, // auto detection
    reactQuery: false,  // auto detection
  },
  {
    /* your custom config */
  },
);

Add script for package.json:

{
  "scripts": {
    "lint": "eslint .",
    "lint:fix": "eslint . --fix"
  }
}

VS Code support (auto fix on save)

Install VS Code ESLint extension

Add the following settings to your .vscode/settings.json:

{
  // Disable the default formatter, use eslint instead
  "prettier.enable": false,
  "editor.formatOnSave": false,

  // Auto fix
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": "explicit",
    "source.organizeImports": "never"
  },

  // Enable eslint for all supported languages
  "eslint.validate": [
    "javascript",
    "javascriptreact",
    "typescript",
    "typescriptreact",
    "html",
    "markdown",
    "json",
    "jsonc",
    "yaml",
    "toml",
    "gql",
    "graphql",
    "css",
    "less",
    "scss",
    "pcss",
    "postcss"
  ]
}

Customization

Normally you only need to import the ncontiero preset:

// eslint.config.js
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero();

And that's it! Or you can configure each integration individually, for example:

// eslint.config.js
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero({
  // TypeScript, React, NextJs, TailwindCSS and TanStack Query are auto-detected,
  // you can also explicitly enable them:
  typescript: true,
  react: true,
  nextjs: true,
  tailwindcss: true,
  reactQuery: true,

  // Disable jsonc, yaml and toml support
  jsonc: false,
  yaml: false,
  toml: false,

  // `.eslintignore` is no longer supported in Flat config, use `ignores` instead
  ignores: [
    "**/fixtures",
    // ...globs
  ],
});

The ncontiero factory function also accepts any number of arbitrary custom config overrides:

// eslint.config.js
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero(
  {
    // Configures for ncontiero's config
  },

  // From the second arguments they are ESLint Flat Configs
  // you can have multiple configs
  {
    files: ["**/*.ts"],
    rules: {},
  },
  {
    rules: {},
  },
);

Rules Overrides

Certain rules would only be enabled in specific files, for example, ts/* rules would only be enabled in .ts. We also provided the overrides options in each integration to make it easier:

// eslint.config.js
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero({
  typescript: {
    overrides: {
      "@typescript-eslint/consistent-type-definitions": ["error", "interface"],
    },
  },
  yaml: {
    overrides: {
      // ...
    },
  },
});

Optional Configs

We provide some optional configs for specific use cases, that we don't include their dependencies by default.

React, Next.js and Tailwind CSS have their dependencies by default.

TanStack Query

To enable TanStack Query support, you need to have the package installed or explicitly enable it:

// eslint.config.js
import { ncontiero } from "@ncontiero/eslint-config";

export default ncontiero({
  reactQuery: true,
});

To work, the @tanstack/eslint-plugin-query package must be installed:

npm i -D @tanstack/eslint-plugin-query

Require @tanstack/eslint-plugin-query >= 5.50.0

References and inspirations

@antfu/eslint-config - Anthony's ESLint config preset.
@sxzz/eslint-config - A opinionated ESLint config preset.

License

This project is licensed under the MIT License - see the LICENSE file for details