babel-helper-module-imports

7.0.0-beta.3 verified Sat Apr 25 auth: no javascript

Babel helper to insert module imports programmatically in AST transforms. v7.0.0-beta.3 is a prerelease of the 7.x series, part of the Babel ecosystem. This package provides functions like addDefault, addNamed, addSideEffect, and addNamespace to inject import statements during plugin execution. It abstracts away import creation, handling scoping, name collisions, and path insertion. The stable 7.x line is in maintenance; 8.x is in development with breaking changes. Key differentiator: designed for Babel plugin authors needing to add imports without manual AST construction.

Common errors

error TypeError: Cannot read properties of undefined (reading 'type') ↓

cause addDefault or addNamed called with invalid path (e.g., not a Program or statement path).

fix

Ensure the first argument is a valid Babel path (e.g., path from visitor).

Warnings

breaking API changes across major versions: Babel 8 may alter function signatures or import paths. ↓

fix Refer to Babel 8 migration guide; test plugins against target version.

deprecated The package name 'babel-helper-module-imports' is legacy; Babel 7+ uses scoped packages under @babel/. ↓

fix Prefer @babel/helper-module-imports in modern projects.

breaking Removal of default export in Babel 8: Some packages may drop default export support. ↓

fix Use named imports only.

Install

npm install babel-helper-module-imports

yarn add babel-helper-module-imports

pnpm add babel-helper-module-imports

Imports

addDefault

wrong

const addDefault = require('babel-helper-module-imports').addDefault

correct

import { addDefault } from 'babel-helper-module-imports'

ESM syntax is preferred; CJS require also works in Node.js.

addNamed

wrong

import addNamed from 'babel-helper-module-imports'

correct

import { addNamed } from 'babel-helper-module-imports'

addNamed is a named export, not a default export.

addSideEffect
```
import { addSideEffect } from 'babel-helper-module-imports'
```
Used for side-effect-only imports (e.g., 'import "source"').
addNamespace
```
import { addNamespace } from 'babel-helper-module-imports'
```
Creates namespace imports like import * as X from 'source'.

Quickstart

Demonstrates adding default and named imports in a Babel plugin using helper functions.

import { addDefault, addNamed } from 'babel-helper-module-imports';
import { types as t } from '@babel/core';

export default function() {
  return {
    visitor: {
      Program(path) {
        // Add default import: import lodash from 'lodash'
        const defaultImport = addDefault(path, 'lodash');

        // Add named import: import { map } from 'lodash'
        const namedImport = addNamed(path, 'map', 'lodash', { nameHint: 'map' });

        // Use the imported identifiers
        console.log(defaultImport.name); // e.g., '_lodash'
        console.log(namedImport.name);   // e.g., '_map'
      }
    }
  };
}