Sensible ESLint + Prettier Config for TypeScript

1.9.0 verified Sat May 09 auth: no javascript

Provides sensible default ESLint rules and Prettier config for TypeScript projects, using ESLint 9 flat config. Version 1.9.0 supports ESLint 9.34+, Prettier 3.6+, TypeScript 5.9+, and includes peer dependencies for TypeScript-ESLint, import resolution, JSDoc, Unicorn, and more. Published by james-hu, it offers builder functions (`eslintConfig`, `prettierConfig`) and a `customiseESLintConfig` helper for programmatic customization of flat config arrays. Supports both ESM and CJS usage. Ships TypeScript type definitions.

Common errors

error ERR_REQUIRE_ESM: require() of ES Module /path/to/node_modules/eslint-config-sensible-prettier-typescript/dist/index.js from /path/to/eslint.config.js not supported. ↓

cause Using CJS require() on an ESM-only package.

fix

Use import syntax in your eslint.config.js or rename file to .mjs and set "type": "module" in package.json.

error Error [ERR_MODULE_NOT_FOUND]: Cannot find module 'eslint-plugin-unicorn' ↓

cause Missing required peer dependency.

fix

Install the missing peer dependency: npm i -D eslint-plugin-unicorn.

error Error: `defineConfig` is not defined ↓

cause Forgetting to import `defineConfig` from `eslint/config` or `eslint` package.

fix

Add import { defineConfig } from 'eslint/config'; at top of eslint.config.js.

error TypeError: eslintConfig is not a function ↓

cause Importing the package incorrectly or using an older version without the builder.

fix

Use import { eslintConfig } from 'eslint-config-sensible-prettier-typescript' and call it as eslintConfig().

Warnings

breaking Migration from v1.5.x to v1.6.0+ requires ESLint 9 flat config; old .eslintrc style is not supported. ↓

fix Switch to eslint.config.js flat config and use eslintConfig() builder.

deprecated CJS require() usage for eslintConfig or prettierConfig may fail in newer versions due to ESM-first design. ↓

fix Use import syntax or ensure your project is set to CommonJS (type: 'commonjs' in package.json).

gotcha The package exports builder functions, not a static config array. Calling eslintConfig() returns an array; spread it inside defineConfig. ↓

fix Use ...eslintConfig() instead of eslintConfig directly.

gotcha Many peer dependencies (e.g., eslint-plugin-unicorn, eslint-plugin-import-x) are required but not auto-installed. Missing them causes runtime errors. ↓

fix Install all peer dependencies listed in package.json or use install-peerdeps.

gotcha The `customiseESLintConfig` function mutates config objects in-place. Be careful when reusing the same config array. ↓

fix Clone the config array and objects if you need to preserve original state.

Install

npm install eslint-config-sensible-prettier-typescript

yarn add eslint-config-sensible-prettier-typescript

pnpm add eslint-config-sensible-prettier-typescript

Imports

eslintConfig

wrong

const { eslintConfig } = require('eslint-config-sensible-prettier-typescript')

correct

import { eslintConfig } from 'eslint-config-sensible-prettier-typescript'

ESM-only since v1.6.2 (ESLint 9 migration); CJS require will fail if package.json type is module.

prettierConfig

wrong

const prettierConfig = require('eslint-config-sensible-prettier-typescript').prettierConfig

correct

import { prettierConfig } from 'eslint-config-sensible-prettier-typescript'

Same as eslintConfig; use ESM import.

customiseESLintConfig
```
import { customiseESLintConfig } from 'eslint-config-sensible-prettier-typescript'
```
Helper function for modifying flat config array programmatically.
buildESLintConfig
```
import { buildESLintConfig } from 'eslint-config-sensible-prettier-typescript'
```
Builder for ESLint flat config, takes options like defaultSourceType.

Quickstart

Shows ESM usage to set up ESLint and Prettier configs with custom rules overrides.

// Install peer dependencies (example command)
// npm i -D eslint prettier typescript @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint-config-prettier eslint-plugin-import-x eslint-plugin-unicorn eslint-config-sensible-prettier-typescript

// eslint.config.js (ESM)
import { eslintConfig } from 'eslint-config-sensible-prettier-typescript';
import { defineConfig } from 'eslint/config';

export default defineConfig([
  ...eslintConfig(),
  {
    rules: {
      'no-console': 'warn',
      '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
    },
  },
]);

// prettier.config.js (ESM)
import { prettierConfig } from 'eslint-config-sensible-prettier-typescript';

export default {
  ...prettierConfig(),
  printWidth: 120,
};