eslint-typegen

eslint-typegen

Generate types from ESLint rule schemas automatically, with auto-completion and type-checking for rule options.

Btw, if you are using @antfu/eslint-config, you may NOT need to setup this, as the types for rules are already shipped with the package.

Usage

npm i eslint-typegen

In your eslint.config.mjs, wrap the export with typegen function:

// @ts-check
/// <reference path="./eslint-typegen.d.ts" />
import typegen from 'eslint-typegen'

export default typegen(
  [
    // ...your normal eslint flat config
  ]
)

Run ESLint once, an eslint-typegen.d.ts file will be generated to augment ESLint's Linter.RulesRecord types, to provide you with auto-completion and type-checking for your ESLint rules configuration based on the ESLint plugins you are using.

It will caluclate the hash of the plugins meta from your flat config, and only regenerate the types when they changes. If you want to force regenerate the types, you can delete the eslint-typegen.d.ts file and run ESLint again.

Low-level API

You can find low-level APIs in the eslint-typegen/core modules.

import fs from 'node:fs/promises'
import { pluginsToRulesDTS } from 'eslint-typegen/core'
import pluginTs from '@typescript-eslint/eslint-plugin'
import pluginN from 'eslint-plugin-n'

const dts = await pluginsToRulesDTS({
  '@typescript-eslint': pluginTs,
  'n': pluginN,
})

await fs.writeFile('eslint-typegen.d.ts', dts)

This can be useful if you want to have more control over the generation process, or even bundle the types with your config package. For example, here is how @antfu/eslint-config does.

How it works

Thanks to that ESLint requires rules to provide the JSONSchema for options, we could leverage that to generate types with json-schema-to-typescript. With the new flat config allowing you to execute the code with fully resolved configs, we managed to sneak in the type generation process on the fly.

Credits

The initial idea comes from @Shinigami92 via his work on eslint-define-config, thanks to him!

Sponsors

License

MIT License © 2023-PRESENT Anthony Fu