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esbuild-plugin-babel-cjs

library1.0.0jsnpmunverified

A CommonJS-compatible Babel plugin for esbuild. Current stable version 1.0.0. This plugin allows you to apply Babel transformations within esbuild bundles when esbuild's native transform capabilities are insufficient. Unlike alternatives (e.g., esbuild-plugin-babel or @aspect-build/esbuild), this package explicitly targets CommonJS environments and provides a simple, minimal API. It requires @babel/core as a peer dependency and delegates Babel configuration to babel.config.json or inline config. Suitable for legacy projects or those locked into CJS.

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npm install esbuild-plugin-babel-cjs

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INSTALL

IMPORT

SIG · ESBUILD-PLUGIN-BAB

esbuild-plugin-babel-cjs

devopsjavascriptv1.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

plugin (default)

✓ const babel = require('esbuild-plugin-babel-cjs');

✗ const babel = require('esbuild-plugin-babel-cjs').default;

Package uses CommonJS default export; require directly returns the plugin function.

plugin (ESM)

✓ import babel from 'esbuild-plugin-babel-cjs';

✗ import { babel } from 'esbuild-plugin-babel-cjs';

Default import works because the module has a default export that resolves to the plugin function.

TypeScript types

✓ import type { BabelPluginConfig } from 'esbuild-plugin-babel-cjs';

✗ import { BabelPluginConfig } from 'esbuild-plugin-babel-cjs';

Type imports are available for config interface. Named type import is correct.

Minimal esbuild config that applies Babel transformations via the plugin. Ensure @babel/core is installed and Babel configuration is set separately.

const esbuild = require('esbuild'); const babel = require('esbuild-plugin-babel-cjs'); esbuild.build({ entryPoints: ['index.js'], bundle: true, outfile: 'main.js', plugins: [babel()], }).catch(() => process.exit(1));

Debug

Known issues

gotchaPlugin does not apply any transforms by default: you must provide a Babel config via babel.config.json or the 'config' option. Without one, Babel runs as a no-op.

fix

Create a babel.config.json or pass config object to babel({ config: { presets: [...], plugins: [...] } }).

affects: >=1.0.0

gotchaIf targeting es5, esbuild must also have target: ['es5'] set; otherwise esbuild will output modern syntax first and Babel may not produce valid es5.

fix

Add target: ['es5'] to esbuild.build options.

affects: >=1.0.0

deprecatedThe package README references esbuild-plugin-babel (without cjs) in the example code (line: const babel = require('esbuild-plugin-babel');). This is a copy-paste error; the correct package is esbuild-plugin-babel-cjs.

fix

Replace require('esbuild-plugin-babel') with require('esbuild-plugin-babel-cjs').

affects: ==1.0.0

gotchaPlugin uses a synchronous transform under the hood; large files or complex Babel presets may cause performance issues or blocking in esbuild's async pipeline.

fix

Consider using esbuild's own transforms when possible for performance.

affects: >=1.0.0

gotchaThe plugin namespace option defaults to an empty string, which may conflict with other plugins. Use a specific namespace like 'babel' to isolate.

fix

Pass babel({ namespace: 'babel' }) to avoid conflicts.

affects: >=1.0.0

Errors

Common errors & fixes

Error: Cannot find module '@babel/core'

@babel/core is not installed or is missing from node_modules.

fix

Run 'npm install @babel/core --save-dev' or add it to devDependencies.

Error: Callback must be a function. Received undefined

Attempting to import a non-existent named export (e.g., import { babel } from 'esbuild-plugin-babel-cjs').

fix

Use default import: import babel from 'esbuild-plugin-babel-cjs' or require('esbuild-plugin-babel-cjs').

Error: No Babel configuration found

No babel.config.json, .babelrc, or inline config provided.

fix

Create a babel.config.json in the project root or pass config option to babel().

ReferenceError: require is not defined

Using require() in an ESM context (e.g., 'type':'module' in package.json).

fix

Use import syntax: import babel from 'esbuild-plugin-babel-cjs';

Upgrade

Version history

1.0.0latest on npm

Audit

Dependencies

@babel/coreoptionalPeer dependency - required to run any Babel transformations.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/nleclerc/esbuild-plugin-babel-cjs ↗

packagehttps://www.npmjs.com/package/esbuild-plugin-babel-cjs ↗