babel-helpers

6.24.1 verified Sat Apr 25 auth: no javascript

A collection of helper functions used by Babel transforms, such as `typeof`, `extends`, `inherits`, and others. Current stable version is v7.x (e.g., v7.29.2), with v8.0.0-rc.3 as the next major pre-release. The package is part of the Babel monorepo and is released on the same cadence as Babel core (typically monthly or as needed). Key differentiator: it provides the internal helper functions that Babel plugins use to generate runtime code, and it is not intended for direct use by most developers; instead, the helpers are bundled into output via `@babel/plugin-transform-runtime` or `@babel/preset-env`.

Common errors

error Cannot find module 'babel-helpers' ↓

cause Package is not installed or not in node_modules.

fix

Run npm install --save-dev babel-helpers

error TypeError: helpers.get is not a function ↓

cause Importing the default export instead of the named export.

fix

Use import { get } from 'babel-helpers' instead of import helpers from 'babel-helpers'

error Error: Unknown helper: myHelper ↓

cause Requested helper name does not exist.

fix

Use helpers.list() to get all available helper names.

Warnings

breaking babel-helpers v6 and v7 have breaking changes in helper APIs. Direct use of helpers package is discouraged; use @babel/plugin-transform-runtime or @babel/preset-env instead. ↓

fix Update to latest v7.x or v8.x and prefer using plugins that handle helpers automatically.

deprecated Some helpers may be deprecated in future versions. Always check the changelog for deprecations. ↓

fix Stay updated with Babel releases and use the specific plugin that provides the helper.

gotcha Importing from 'babel-helpers' does not work in browser environments without a bundler. The package is designed for Node.js and requires transformation. ↓

fix Use a bundler like webpack or rollup with babel-loader to include helpers.

gotcha The 'get' function expects a string name and returns an AST node. If the name is invalid, it may throw or return undefined. ↓

fix Validate helper names using the 'list' function or refer to the Babel source code.

Install

npm install babel-helpers

yarn add babel-helpers

pnpm add babel-helpers

Imports

get
wrong
```
import helpers from 'babel-helpers'
```
correct
```
import { get } from 'babel-helpers'
```
Default export is not available. Use named import for the 'get' function.
list
wrong
```
const list = require('babel-helpers').list
```
correct
```
import { list } from 'babel-helpers'
```
Note that list() returns an array of all helper names. In CJS, require is fine.
all
wrong
```
const helpers = require('babel-helpers')
```
correct
```
import * as helpers from 'babel-helpers'
```
In ESM, use namespace import to access both 'get' and 'list' as properties.

Quickstart

Demonstrates importing and using the 'get' function to retrieve a helper by name, and checking its AST type with babel-types.

import { get } from 'babel-helpers';
import * as t from 'babel-types';

const typeofHelper = get('typeof');
console.log(t.isExpressionStatement(typeofHelper)); // true