webpack-contrib / Uglifyjs Webpack Plugin
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UglifyJS Webpack Plugin
This plugin uses uglify-js to minify your JavaScript.
Requirements
This module requires a minimum of Node v6.9.0 and Webpack v4.0.0.
Getting Started
To begin, you'll need to install uglifyjs-webpack-plugin:
$ npm install uglifyjs-webpack-plugin --save-dev
Then add the plugin to your webpack config. For example:
webpack.config.js
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
module.exports = {
optimization: {
minimizer: [new UglifyJsPlugin()],
},
};
And run webpack via your preferred method.
Options
test
Type: String|RegExp|Array<String|RegExp>
Default: /\.js(\?.*)?$/i
Test to match files against.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
test: /\.js(\?.*)?$/i,
}),
],
},
};
include
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to include.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
include: /\/includes/,
}),
],
},
};
exclude
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to exclude.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
exclude: /\/excludes/,
}),
],
},
};
chunkFilter
Type: Function<(chunk) -> boolean>
Default: () => true
Allowing to filter which chunks should be uglified (by default all chunks are uglified).
Return true to uglify the chunk, false otherwise.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
chunkFilter: (chunk) => {
// Exclude uglification for the `vendor` chunk
if (chunk.name === 'vendor') {
return false;
}
return true;
},
}),
],
},
};
cache
Type: Boolean|String
Default: false
Enable file caching.
Default path to cache directory: node_modules/.cache/uglifyjs-webpack-plugin.
ℹ️ If you use your own
minifyfunction please read theminifysection for cache invalidation correctly.
Boolean
Enable/disable file caching.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: true,
}),
],
},
};
String
Enable file caching and set path to cache directory.
webpack.config.js
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: 'path/to/cache',
}),
],
},
};
cacheKeys
Type: Function<(defaultCacheKeys, file) -> Object>
Default: defaultCacheKeys => defaultCacheKeys
Allows you to override default cache keys.
Default cache keys:
({
'uglify-js': require('uglify-js/package.json').version, // uglify version
'uglifyjs-webpack-plugin': require('../package.json').version, // plugin version
'uglifyjs-webpack-plugin-options': this.options, // plugin options
path: compiler.outputPath ? `${compiler.outputPath}/${file}` : file, // asset path
hash: crypto
.createHash('md4')
.update(input)
.digest('hex'), // source file hash
});
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: true,
cacheKeys: (defaultCacheKeys, file) => {
defaultCacheKeys.myCacheKey = 'myCacheKeyValue';
return defaultCacheKeys;
},
}),
],
},
};
parallel
Type: Boolean|Number
Default: false
Use multi-process parallel running to improve the build speed.
Default number of concurrent runs: os.cpus().length - 1.
ℹ️ Parallelization can speedup your build significantly and is therefore highly recommended.
Boolean
Enable/disable multi-process parallel running.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
parallel: true,
}),
],
},
};
Number
Enable multi-process parallel running and set number of concurrent runs.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
parallel: 4,
}),
],
},
};
sourceMap
Type: Boolean
Default: false
Use source maps to map error message locations to modules (this slows down the compilation).
If you use your own minify function please read the minify section for handling source maps correctly.
⚠️
cheap-source-mapoptions don't work with this plugin.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
sourceMap: true,
}),
],
},
};
minify
Type: Function
Default: undefined
Allows you to override default minify function. By default plugin uses uglify-js package. Useful for using and testing unpublished versions or forks.
⚠️ Always use
requireinsideminifyfunction whenparalleloption enabled.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
minify(file, sourceMap) {
const extractedComments = [];
// Custom logic for extract comments
const { error, map, code, warnings } = require('uglify-module') // Or require('./path/to/uglify-module')
.minify(file, {
/* Your options for minification */
});
return { error, map, code, warnings, extractedComments };
},
}),
],
},
};
uglifyOptions
Type: Object
Default: default
UglifyJS minify options.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
uglifyOptions: {
warnings: false,
parse: {},
compress: {},
mangle: true, // Note `mangle.properties` is `false` by default.
output: null,
toplevel: false,
nameCache: null,
ie8: false,
keep_fnames: false,
},
}),
],
},
};
extractComments
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>
Default: false
Whether comments shall be extracted to a separate file, (see details).
By default extract only comments using /^\**!|@preserve|@license|@cc_on/i regexp condition and remove remaining comments.
If the original file is named foo.js, then the comments will be stored to foo.js.LICENSE.
The uglifyOptions.output.comments option specifies whether the comment will be preserved, i.e. it is possible to preserve some comments (e.g. annotations) while extracting others or even preserving comments that have been extracted.
Boolean
Enable/disable extracting comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: true,
}),
],
},
};
String
Extract all or some (use /^\**!|@preserve|@license|@cc_on/i RegExp) comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: 'all',
}),
],
},
};
RegExp
All comments that match the given expression will be extracted to the separate file.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: /@extract/i,
}),
],
},
};
Function<(node, comment) -> Boolean>
All comments that match the given expression will be extracted to the separate file.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: function(astNode, comment) {
if (/@extract/i.test(comment.value)) {
return true;
}
return false;
},
}),
],
},
};
Object
Allow to customize condition for extract comments, specify extracted file name and banner.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: {
condition: /^\**!|@preserve|@license|@cc_on/i,
filename(file) {
return `${file}.LICENSE`;
},
banner(licenseFile) {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
condition
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>
Condition what comments you need extract.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: {
condition: 'some',
filename(file) {
return `${file}.LICENSE`;
},
banner(licenseFile) {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
filename
Type: Regex|Function<(string) -> String>
Default: ${file}.LICENSE
The file where the extracted comments will be stored.
Default is to append the suffix .LICENSE to the original filename.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: {
condition: /^\**!|@preserve|@license|@cc_on/i,
filename: 'extracted-comments.js',
banner(licenseFile) {
return `License information can be found in ${licenseFile}`;
},
},
}),
],
},
};
banner
Type: Boolean|String|Function<(string) -> String>
Default: /*! For license information please see ${commentsFile} */
The banner text that points to the extracted file and will be added on top of the original file.
Can be false (no banner), a String, or a Function<(string) -> String> that will be called with the filename where extracted comments have been stored.
Will be wrapped into comment.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
extractComments: {
condition: true,
filename(file) {
return `${file}.LICENSE`;
},
banner(commentsFile) {
return `My custom banner about license information ${commentsFile}`;
},
},
}),
],
},
};
warningsFilter
Type: Function<(warning, source) -> Boolean>
Default: () => true
Allow to filter uglify-js warnings.
Return true to keep the warning, false otherwise.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
warningsFilter: (warning, source) => {
if (/Dropping unreachable code/i.test(warning)) {
return true;
}
if (/filename\.js/i.test(source)) {
return true;
}
return false;
},
}),
],
},
};
Examples
Cache And Parallel
Enable cache and multi-process parallel running.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
cache: true,
parallel: true,
}),
],
},
};
Preserve Comments
Extract all legal comments (i.e. /^\**!|@preserve|@license|@cc_on/i) and preserve /@license/i comments.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
uglifyOptions: {
output: {
comments: /@license/i,
},
},
extractComments: true,
}),
],
},
};
Remove Comments
If you avoid building with comments, set uglifyOptions.output.comments to false as in this config:
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
uglifyOptions: {
output: {
comments: false,
},
},
}),
],
},
};
Custom Minify Function
Override default minify function - use terser for minification.
webpack.config.js
module.exports = {
optimization: {
minimizer: [
new UglifyJsPlugin({
// Uncomment lines below for cache invalidation correctly
// cache: true,
// cacheKeys(defaultCacheKeys) {
// delete defaultCacheKeys['uglify-js'];
//
// return Object.assign(
// {},
// defaultCacheKeys,
// { 'uglify-js': require('uglify-js/package.json').version },
// );
// },
minify(file, sourceMap) {
// https://github.com/mishoo/UglifyJS2#minify-options
const uglifyJsOptions = {
/* your `uglify-js` package options */
};
if (sourceMap) {
uglifyJsOptions.sourceMap = {
content: sourceMap,
};
}
return require('terser').minify(file, uglifyJsOptions);
},
}),
],
},
};
Contributing
Please take a moment to read our contributing guidelines if you haven't yet done so.