terser-webpack-plugin
This plugin uses terser 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 terser-webpack-plugin
:
$ npm install terser-webpack-plugin --save-dev
Then add the plugin to your webpack
config. For example:
webpack.config.js
const TerserPlugin = require('terser-webpack-plugin');
module.exports = {
//...
optimization: {
minimizer: [new TerserPlugin()]
}
};
And run webpack
via your preferred method.
Options
test
Type: String|RegExp|Array<String|RegExp>
Default: /\.js(\?.*)?$/i
Test to match files against.
// in your webpack.config.js
new TerserPlugin({
test: /\.js(\?.*)?$/i
})
include
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to include.
// in your webpack.config.js
new TerserPlugin({
include: /\/includes/
})
exclude
Type: String|RegExp|Array<String|RegExp>
Default: undefined
Files to exclude.
// in your webpack.config.js
new TerserPlugin({
exclude: /\/excludes/
})
cache
Type: Boolean|String
Default: false
Enable file caching.
Default path to cache directory: node_modules/.cache/terser-webpack-plugin
.
ℹ️ If you use your own
minify
function please read theminify
section for cache invalidation correctly.
Boolean
Enable/disable file caching.
// in your webpack.config.js
new TerserPlugin({
cache: true
})
String
Enable file caching and set path to cache directory.
webpack.config.js
// in your webpack.config.js
new TerserPlugin({
cache: 'path/to/cache'
})
cacheKeys
Type: Function<(defaultCacheKeys, file) -> Object>
Default: defaultCacheKeys => defaultCacheKeys
Allows you to override default cache keys.
Default cache keys:
({
terser: require('terser/package.json').version, // terser version
'terser-webpack-plugin': require('../package.json').version, // plugin version
'terser-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
});
// in your webpack.config.js
new TerserPlugin({
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.
// in your webpack.config.js
new TerserPlugin({
parallel: true
})
Number
Enable multi-process parallel running and set number of concurrent runs.
// in your webpack.config.js
new TerserPlugin({
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-map
options don't work with this plugin.
// in your webpack.config.js
new TerserPlugin({
sourceMap: true
})
minify
Type: Function
Default: undefined
Allows you to override default minify function. By default plugin uses terser package. Useful for using and testing unpublished versions or forks.
⚠️ Always userequire
insideminify
function whenparallel
option enabled.
// in your webpack.config.js
new TerserPlugin({
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 };
}
})
terserOptions
Type: Object
Default: default
Terser minify options.
// in your webpack.config.js
new TerserPlugin({
terserOptions: {
ecma: undefined,
warnings: false,
parse: {},
compress: {},
mangle: true, // Note `mangle.properties` is `false` by default.
module: false,
output: null,
toplevel: false,
nameCache: null,
ie8: false,
keep_classnames: undefined,
keep_fnames: false,
safari10: false
}
})
extractComments
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>|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 terserOptions.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.
// in your webpack.config.js
new TerserPlugin({
extractComments: true
})
String
Extract all
or some
(use /^\**!|@preserve|@license|@cc_on/i
RegExp) comments.
// in your webpack.config.js
new TerserPlugin({
extractComments: 'all'
})
RegExp
All comments that match the given expression will be extracted to the separate file.
// in your webpack.config.js
new TerserPlugin({
extractComments: /@extract/i
})
Function<(node, comment) -> Boolean>
All comments that match the given expression will be extracted to the separate file.
// in your webpack.config.js
new TerserPlugin({
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.
// in your webpack.config.js
new TerserPlugin({
extractComments: {
condition: /^\**!|@preserve|@license|@cc_on/i,
filename(file) {
return `${file}.LICENSE`;
},
banner(licenseFile) {
return `License information can be found in ${licenseFile}`;
}
}
})
condition
Type: Boolean|String|RegExp|Function<(node, comment) -> Boolean|Object>
Condition what comments you need extract.
// in your webpack.config.js
new TerserPlugin({
extractComments: {
condition: 'some',
filename(file) {
return `${file}.LICENSE`;
},
banner(licenseFile) {
return `License information can be found in ${licenseFile}`;
}
}
})
filename
Type: String|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.
// in your webpack.config.js
new TerserPlugin({
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 ${commentsFile} */
The banner text that points to the extracted file and will be added on top of the original file.
Can be false
(no banner), a String
, or a Function<(string) -> String>
that will be called with the filename where extracted comments have been stored.
Will be wrapped into comment.
// in your webpack.config.js
new TerserPlugin({
extractComments: {
condition: true,
filename(file) {
return `${file}.LICENSE`;
},
banner(commentsFile) {
return `My custom banner about license information ${commentsFile}`;
}
}
})
warningsFilter
Type: Function<(warning, source) -> Boolean>
Default: () => true
Allow to filter terser warnings.
Return true
to keep the warning, false
otherwise.
// in your webpack.config.js
new TerserPlugin({
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.
// in your webpack.config.js
const TerserPlugin = require('terser-webpack-plugin');
module.exports = {
//...
optimization: {
minimizer: [
new TerserPlugin({
cache: true,
parallel: true
})
]
}
};
Preserve Comments
Extract all legal comments (i.e. /^\**!|@preserve|@license|@cc_on/i
) and preserve /@license/i
comments.
// in your webpack.config.js
const TerserPlugin = require('terser-webpack-plugin');
module.exports = {
//...
optimization: {
minimizer: [
new TerserPlugin({
terserOptions: {
output: {
comments: /@license/i
}
},
extractComments: true
})
]
}
};
Custom Minify Function
Override default minify function - use uglify-js
for minification.
// in your webpack.config.js
const TerserPlugin = require('terser-webpack-plugin');
module.exports = {
//...
optimization: {
minimizer: [
new TerserPlugin({
// Uncomment lines below for cache invalidation correctly
// cache: true,
// cacheKeys(defaultCacheKeys) {
// delete defaultCacheKeys.terser;
//
// 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('uglify-js').minify(file, uglifyJsOptions);
},
})
]
}
};
Contributing
Please take a moment to read our contributing guidelines if you haven't yet done so.