@effective/eslint-cfg NPM

ESLint Config Builder

A TypeScript-based library for generating ESLint configurations in the Flat Config format, targeting TypeScript projects with optional NodeJS and React support.

Features

Generates ESLint Flat Configs for ESLint v9.
Requires TypeScript and optionally supports React and NodeJS
Automatically drops rules handled by Prettier.
Uses Biome data to optionally disable rules supported by Biome.

Config options

strict: Enables strict linting rules (TypeScript mostly)
style: Adds additional rules for style guidelines and import sorting/grouping.
fast: Drop rules which require typing information (much faster)
biome: Drop rules which are implemented identically in Biome (for performance reasons)
disabled: Only return disabled rules. Helpful to add to the end when using custom rules.
react: Add all recommended ReactJS/Hooks/Storybook checks
node: Add all recommended NodeJS checks

Installation

npm install @effective/eslint-cfg

Usage

// eslint.config.ts
import { getConfig } from "@effective/eslint-cfg"

const config = getConfig({
  react: true,
  strict: true,
  style: true
})

export default [
  {
    ignores: ["node_modules", "dist"]
  },
  {
    settings: {
      react: {
        version: "19.0"
      }
    }
  },
  {
    files: ["**/*.ts", "**/*.tsx"]
  },
  {
    rules: {
      // custom rules / overrides
    }
  }
]

Note: Using TS configuration files work perfectly fine since ESLint v9 but requires installing jiti.

API

The package exports the following functions:

`getConfig(options)`

Loads an ESLint configuration based on the provided options.

options - The configuration options
Returns: Promise resolving to the loaded ESLint configuration

import { getConfig } from "@effective/eslint-cfg"

const options = {
  react: true,
  strict: true,
  style: true
}

const config = await getConfig(options)
console.log(config.rules) // Access the ESLint rules

`setRuleSeverity(config, ruleName, severity)`

Changes the severity of a specific ESLint rule in the configuration.

config - The ESLint configuration
ruleName - The name of the rule to modify
severity - The new severity level ("error" | "warn" | "off")
Throws: When the config has no rules or the rule is not configured

import { getConfig, setRuleSeverity } from "@effective/eslint-cfg"

const config = await getConfig(options)
// Change 'no-console' rule to warning
setRuleSeverity(config, "no-console", "warn")

`configureRule(config, ruleName, options)`

Configures a specific ESLint rule in the configuration with its severity and optional parameters. Unlike setRuleSeverity, this method preserves the existing severity level while allowing to update the rule's options.

config - The ESLint configuration
ruleName - The name of the rule to configure
options - Optional array of configuration options for the rule
Throws: When the config has no rules or the rule is not configured

import { getConfig, configureRule } from "@effective/eslint-cfg"

const config = await getConfig(options)
// Configure 'max-len' rule with options while preserving severity
configureRule(config, "max-len", [{ code: 100, tabWidth: 2 }])

`disableRule(config, ruleName)`

Disables a specific ESLint rule in the configuration by removing it.

config - The ESLint configuration
ruleName - The name of the rule to disable
Throws: When the config has no rules or the rule is not configured

import { getConfig, disableRule } from "@effective/eslint-cfg"

const config = await getConfig(options)
// Completely remove the 'no-console' rule
disableRule(config, "no-console")

`addRule(config, ruleName, severity, options)`

Adds a new ESLint rule to the configuration with specified severity and options.

config - The ESLint configuration
ruleName - The name of the rule to add
severity - The severity level for the rule ("warn" | "error")
options - Additional options for the rule configuration
Throws: When the config has no rules or the rule is already configured

import { getConfig, addRule } from "@effective/eslint-cfg"

const config = await getConfig(options)
// Add new rule with options
addRule(config, "max-len", "error", [{ code: 100 }])

`disableAllRulesBut(config, ruleName)`

Disables all rules except the one specified. Useful for focusing on a single rule for debugging.

config - The ESLint configuration
ruleName - The name of the rule to add
Throws: When the config has no rules or the rule is already configured

Complete Example

import {
  getConfig,
  setRuleSeverity,
  disableRule,
  addRule
} from "@effective/eslint-cfg"

async function customizeEslintConfig() {
  // Load the base configuration
  const config = await getConfig({
    react: true,
    strict: true,
    style: true
  })

  // Customize rule severities
  setRuleSeverity(config, "no-console", "warn")
  setRuleSeverity(config, "no-unused-vars", "error")

  // Disable rules you don't want
  disableRule(config, "complexity")

  // Add new rule with options
  addRule(config, "max-len", "error", [{ code: 100 }])

  return config
}