eslint-transforms

3.0.0 verified Sat Apr 25 auth: no javascript

A collection of jscodeshift-based codemods for automating ESLint rule upgrades across major versions. Current stable version is 3.0.0, released June 2024. Active development with recent transforms for ESLint v9 migration. Key differentiator: provides automated transforms for rule format changes (new-rule-format, v9-rule-migration) that would otherwise require manual refactoring. Requires Node >=20 and jscodeshift as a peer dependency. Alternative to manual upgrading or using ESLint's built-in migration tools.

Common errors

error Error: Cannot find module 'eslint-transforms' ↓

cause Package not installed or incorrect import path.

fix

Run npm install eslint-transforms --save-dev. If using ESM, ensure package.json has type: module or use .mjs extension.

error Error [ERR_REQUIRE_ESM]: require() of ES Module ... from ... not supported. ↓

cause Using CommonJS require() with ESM-only package (v3+).

fix

Switch to ESM imports: import eslintTransforms from 'eslint-transforms' or convert your script to ESM.

error TypeError: eslintTransforms is not a function ↓

cause Incorrect usage: attempting to call the package as a function instead of using CLI or named exports.

fix

Use CLI: npx eslint-transforms v9-rule-migration <path>. Or import named transform functions.

error Error: Node.js version 14 is not supported. ↓

cause Running on Node <20 with v3.0.0.

fix

Upgrade Node to v20 or higher. If unable, use v2.x with Node 12+ by pinning version: npm install eslint-transforms@2.

Warnings

breaking Node.js >=20 required. Older versions unsupported. ↓

fix Upgrade Node.js to v20 or higher.

breaking ESM-only from v3.0.0. CommonJS require() will fail. ↓

fix Use ESM imports or ensure compatibility with ESM modules.

gotcha The new-rule-format transform does not work for rules using ES6 module syntax. ↓

fix Convert ES6 modules to CommonJS before running the transform, or manually update the rule.

gotcha Transforms modify files in-place. No undo mechanism provided. ↓

fix Commit changes or use version control before running transforms. Use --dry flag if available (check docs).

breaking Drop support for Node <12 in v2.0.0. ↓

fix Upgrade to Node >=12 to use v2+, or stay on v1.x if stuck on older Node.

Install

npm install eslint-transforms

yarn add eslint-transforms

pnpm add eslint-transforms

Imports

eslint-transforms CLI
wrong
```
npm run eslint-transforms (unless configured in package.json)
```
correct
```
npx eslint-transforms <transform-name> <path>
```
CLI is the primary usage; no JavaScript import needed. Use npx for direct execution.
default import (if used programmatically)
wrong
```
const eslintTransforms = require('eslint-transforms')
```
correct
```
import eslintTransforms from 'eslint-transforms'
```
Package is ESM-only since v3. CommonJS require will fail. Programmatic usage is undocumented but possible.

transform functions

wrong

const newRuleFormat = require('eslint-transforms').newRuleFormat

correct

import { newRuleFormat, v9RuleMigration } from 'eslint-transforms'

Individual transforms are exported as named exports. Check package for actual export names.

Quickstart

Install the package as a dev dependency and run the v9-rule-migration transform on a rules directory, then new-rule-format on legacy rules.

npm install eslint-transforms --save-dev
npx eslint-transforms v9-rule-migration ./lib/rules
npx eslint-transforms new-rule-format ./legacy-rules