UglifyJS Webpack Plugin
This plugin uses [UglifyJS](https://github.com/mishoo/UglifyJS2) to minify your JavaScript.
Note that webpack contains the same plugin under webpack.optimize.UglifyJsPlugin
. This is a standalone version for those that want to control the version of UglifyJS. The documentation is valid apart from the installation instructions in that case.
Install
With Yarn:
yarn add uglifyjs-webpack-plugin --dev
With npm:
npm install uglifyjs-webpack-plugin --save-dev
Important! The plugin has a peer dependency to uglify-js, so in order to use the plugin, also uglify-js has to be installed. The currently (2017/1/25) available uglify-js npm packages, however, do not support minification of ES6 code. In order to support ES6, an ES6-capable, a.k.a. harmony, version of UglifyJS has to be provided.
If your minification target is ES6:
yarn add git://github.com/mishoo/UglifyJS2
If your minification target is ES5:
yarn add uglify-js --dev
Usage
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
module.exports = {
entry: {...},
output: {...},
module: {...},
plugins: [
new UglifyJSPlugin()
]
};
Options
This plugin supports UglifyJS features as discussed below:
Property | Type | Default | Description |
---|
compress | boolean, object | true | See UglifyJS documentation. |
mangle | boolean, object | true | See below. |
beautify | boolean | false | Beautify output. |
output | An object providing options for UglifyJS OutputStream | | Lower level access to UglifyJS output. |
comments | boolean, RegExp, function(astNode, comment) -> boolean | Defaults to preserving comments containing /*! , /**! , @preserve or @license . | Comment related configuration. |
extractComments | boolean, RegExp, function (astNode, comment) -> boolean, object | false | Whether comments shall be extracted to a separate file, see below. |
sourceMap | boolean | false | Use SourceMaps to map error message locations to modules. This slows down the compilation. |
test | RegExp, Array | /.js($|?)/i | Test to match files against. |
include | RegExp, Array | | Test only include files. |
exclude | RegExp, Array | | Files to exclude from testing. |
Mangling
mangle.props (boolean|object)
- Passing true
or an object enables and provides options for UglifyJS property mangling - see UglifyJS documentation for mangleProperties for options.
Note: the UglifyJS docs warn that you will probably break your source if you use property mangling, so if you aren’t sure why you’d need this feature, you most likely shouldn’t be using it! You can tweak the behavior as below:
new UglifyJsPlugin({
mangle: {
except: ['$super', '$', 'exports', 'require']
}
})
The extractComments
option can be
true
: All comments that normally would be preserved by the comments
option will be moved to a separate file. If the original file is named foo.js
, then the comments will be stored to foo.js.LICENSE
- regular expression (given as
RegExp
or string
) or a function (astNode, comment) -> boolean
:
All comments that match the given expression (resp. are evaluated to true
by the function) will be extracted to the separate file. The 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. - an
object
consisting of the following keys, all optional:
condition
: regular expression or function (see previous point)filename
: The file where the extracted comments will be stored. Can be either a string
or function (string) -> string
which will be given the original filename. Default is to append the suffix .LICENSE
to the original filename.banner
: The banner text that points to the extracted file and will be added on top of the original file. will be added to 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.
Default: /*! For license information please see foo.js.LICENSE */
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