eslint-config-foxkit

This package contains an opinionated set of base configs for ESLint and typescript-eslint.

Installation

Install with your package manager of choice:

pnpm add --save-dev eslint-config-foxkit eslint @eslint/js typescript@~5.7

Note: To use ESLint v8 please install [email protected] @eslint/[email protected]. Support for v8 will be dropped in the future when required for updating any dependencies of this configuration package.

Usage with Flat Configuration System

Add a Flat Config in your project like this:

import foxkit from "eslint-config-foxkit/flat.js";

export default [
  foxkit.base,
  foxkit.typescript,
  foxkit.configureTS({ tsconfigRootDir: import.meta.dirname })
];

You may also add other configs on top, such as prettier, as well as your own overrides.

Usage in CommonJS projects

If your project does not set "type": "module" in package.json your config will be CommonJS instead (unless explicitly named "eslint.config.mjs"). If this is the case use require("eslint-config-foxkit/flat") instead.

const foxkit = require("eslint-config-foxkit/flat");

module.exports = [
  foxkit.base,
  foxkit.typescript,
  foxkit.configureTS({ tsconfigRootDir: __dirname })
];

Extending base configs

You can use tsEslint.config to extend the base configs, for example to add the file extensions for a framework like Astro:

import foxkit from "eslint-config-foxkit/flat.js";
import tsEslint from "typescript-eslint";

const foxkitTS = tsEslint.config({
  files: foxkit.tsFiles.concat("**/*.astro"),
  extends: [
    foxkit.typescript,
    foxkit.configureTS({
      tsconfigRootDir: import.meta.dirname,
      extraFileExtensions: [".astro"]
    })
  ]
});

export default [
  foxkit.base,
  // spread is required here as tsEslint.config returns an array!
  ...foxkitTS
];

Usage with other base configurations

Alternatively you can access the rulesets by importing from eslint-config-foxkit/rules. If you are already using a base config like from your project's framework you may want to add a customized config object with our rules as well as the no-await-in-promise plugin like this:

import framework from "@framework/eslint-config";
import * as promisePlugin from "eslint-plugin-no-await-in-promise";
import foxkit from "eslint-config-foxkit/flat.js";
import foxkitRules from "eslint-config-foxkit/rules/base.js";

// This line is only required in ES Module projects:
const __dirname = new URL(".", import.meta.url).pathname.slice(0, -1);

export default [
  framework,
  {
    plugins: { "no-await-in-promise": promisePlugin },
    rules: { ...foxkitRules }
  },
  foxkit.typescript,
  foxkit.configureTS({ tsconfigRootDir: __dirname })
];

Usage with the Legacy Configuration System

Note: The Legacy Config System will be removed in ESLint v10. Support it will be dropped when ESLint v8 is no longer supported!

Simply add "foxkit" to your extends array in your .eslintrc.cjs file and set up the parserOptions for typescript-eslint:

module.exports = {
  extends: ["foxkit"],
  overrides: [
    {
      files: ["**/*.ts?(x)"],
      parserOptions: {
        project: true,
        tsconfigRootDir: __dirname
      }
    }
  ]
};

Note: Should you need to add a file extension to the typescript override you can import it directly:

const foxkitOverrides = require("eslint-config-foxkit/legacy/overrides");
const foxkitTS = foxkitOverrides.typescript;
foxkitTS.files.push("**/*.astro");

module.exports = {
  extends: ["foxkit"],
  overrides: [
    {
      files: foxkitTS.files,
      parserOptions: {
        project: true,
        tsconfigRootDir: __dirname
      }
    },
    foxkitOverrides.typescript // re-insert patched version of the override
  ]
};

Note for VSCode

As of right now the ESLint plugin available for VSCode has experimental support for Flat Config hidden behind a setting. In your project simply create a .vscode directory with a settings.json file with the following content (or add to it if you already have one):

{
  "eslint.useFlatConfig": true
}

This enables the setting on a workspace-level, so when switching between projects the setting remains disabled for projects using the old config system. Also note that the .mjs and .cjs extensions may not get picked up correctly, so your config file should always be called eslint.config.js.

Note for pnpm

As of pnpm v10 there are issues with accessing subdependencies, such as typescript-eslint (a dependency of this config package). If you are experiencing problems with ESLint or TypeScript being unable to find subdependencies try adding the following options to your .npmrc file:

auto-install-peers=true
node-linker=hoisted

See also

• eslint-config-foxkit-react: Our base configurations for React/Preact development

Migrating from v4

• The import path for Flat Configs has changed to "eslint-config-foxkit/flat.js"
• TypeScript-ESLint dependency has been changed to the typescript-eslint package, as such a cleaner way to extend base configs is now available (see Extending base configs)

Migrating from v3

• Install [email protected] or eslint@^9 and matching version of @eslint/js
• Install typescript@~5.7
• eslint-plugin-no-await-in-promise as well as the typescript-eslint packages are now dependencies and can be removed from your own package.json
• Use the documentation above to adjust your configuration. Base configs are now supplied as objects again, a utility function for setting up typescript-eslint is provided separately as configureTS now.
• Non-strict configurations have been removed and are no longer available.
• The configs for React/Preact have moved to eslint-config-foxkit-react which must be set up separately now.
• TypeScript configs are now included in the base imports ("foxkit" for legacy extends, eslint-config-foxkit/flat.js for flat configs).
• Astro support has been removed again. See instructions above for how to re-add support (or add support for any other framework such as Vue or Svelte).