Registry / devops / babel-plugin-uglify

babel-plugin-uglify

library1.0.2jsnpmunverified

Babel plugin that integrates UglifyJS minification directly into the Babel pipeline without needing to generate and re-parse code. v1.0.2 is the latest stable release. This plugin works on the Mozilla AST (SpiderMonkey format) used internally by Babel, avoiding repeated code generation and parsing. It is intended for Babel 5.x only, as Babel 6+ uses different AST formats. No longer actively maintained; alternatives include babel-minify (babili) or terser-based plugins. Key differentiator: direct AST-level minification preserves source maps and avoids overhead of stringifying and re-parsing code.

devops

npm install babel-plugin-uglify

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-PLUGIN-UGLIF

babel-plugin-uglify

devopsjavascriptv1.0.2

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

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

plugin

✓ // In .babelrc: {"plugins": ["uglify:after"]}

✗ {"plugins": ["uglify"]}

Must use ':after' suffix to ensure it runs after ES6 transforms. Without it, UglifyJS may receive untransformed ES6 code and fail.

Shows how to configure babel-plugin-uglify via .babelrc and Node API, including the required ':after' suffix.

// .babelrc example { "plugins": ["uglify:after"] } // Node API example var babel = require('babel'); babel.transform('const x = 1;', { plugins: ['uglify:after'] }, function(err, result) { console.log(result.code); });

Debug

Known issues

deprecatedbabel-plugin-uglify is deprecated. Babel 6+ does not use Mozilla AST, and this plugin is incompatible. Use babel-minify (babili) or plugins based on terser.

fix

Migrate to @babel/plugin-minify (babel-minify) or babel-plugin-terser.

affects: >=1.0.0

breakingThe plugin requires Babel 5.x. It will not work with Babel 6 or later due to AST format changes.

fix

Use Babel 5 or switch to a Babel 6+ compatible minifier.

affects: >=1.0.0

gotchaThe plugin must be specified with ':after' suffix (e.g., 'uglify:after') in Babel plugins list; otherwise it runs before ES6 transforms and UglifyJS will fail on ES6 syntax.

fix

Add ':after' suffix to plugin name in .babelrc or programmatic options.

affects: >=1.0.0

deprecatedUglifyJS itself is less actively maintained than terser. Consider using terser-based plugins for better ES6+ support and ongoing maintenance.

fix

Use babel-plugin-terser instead of babel-plugin-uglify.

affects: >=1.0.0

Errors

Common errors & fixes

Couldn't find preset "es2015" relative to directory

Missing Babel preset when trying to run transforms before uglify

fix

Install and configure Babel presets (e.g., babel-preset-es2015) in .babelrc or programmatic options.

Unexpected token: name (x)

Plugin ran before ES6 transformers, so UglifyJS encountered ES6 syntax

fix

Ensure plugin is specified with ':after' suffix (e.g., 'uglify:after') so it runs after ES6 transforms.

require('babel').transform is not a function

Using Babel 6+ API with babel-plugin-uglify which is only for Babel 5

fix

Use Babel 5 API (require('babel')) or switch to a Babel 6+ compatible minifier plugin.

Upgrade

Version history

1.0.2latest on npm

Audit

Dependencies

uglify-jsoptionalPeer dependency for minification engine

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/rreverser/babel-plugin-uglify ↗

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