grunt-contrib-uglify v0.11.0
Minify javascript files with UglifyJS
Getting Started
This plugin requires Grunt >=0.4.0
If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:
npm install grunt-contrib-uglify --save-dev
Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:
grunt.loadNpmTasks('grunt-contrib-uglify');
Uglify task
Run this task with the grunt uglify
command.
Task targets, files and options may be specified according to the grunt Configuring tasks guide.
Migrating from 2.x to 3.x
Version 3.x
introduced changes to configuring source maps. Accordingly, if you don't use the source map options you should be able to upgrade seamlessly. If you do use source maps, see below.
Removed options
sourceMappingURL
- This is calculated automatically now
sourceMapPrefix
- No longer necessary for the above reason
Changed options
sourceMap
- Only accepts a Boolean
value. Generates a map with a default name for you
sourceMapRoot
- The location of your sources is now calculated for you when sourceMap
is set to true
but you can set manual source root if needed
New options
sourceMapName
- Accepts a string or function to change the location or name of your map
sourceMapIncludeSources
- Embed the content of your source files directly into the map
expression
- Accepts a Boolean
value. Parse a single expression (JSON or single functions)
quoteStyle
- Accepts integers 0
(default), 1
, 2
, 3
. Enforce or preserve quotation mark style.
Options
This task primarily delegates to UglifyJS2, so please consider the UglifyJS documentation as required reading for advanced configuration.
mangle
Type: Boolean
Object
Default: {}
Turn on or off mangling with default options. If an Object
is specified, it is passed directly to ast.mangle_names()
and ast.compute_char_frequency()
(mimicking command line behavior). View all options here.
compress
Type: Boolean
Object
Default: {}
Turn on or off source compression with default options. If an Object
is specified, it is passed as options to UglifyJS.Compressor()
. View all options here.
beautify
Type: Boolean
Object
Default: false
Turns on beautification of the generated source code. An Object
will be merged and passed with the options sent to UglifyJS.OutputStream()
. View all options here
expression
Type: Boolean
Default: false
Parse a single expression, rather than a program (for parsing JSON)
report
Choices: 'min'
, 'gzip'
Default: 'min'
Either report only minification result or report minification and gzip results.
This is useful to see exactly how well clean-css is performing but using 'gzip'
will make the task take 5-10x longer to complete. Example output.
sourceMap
Type: Boolean
Default: false
If true
, a source map file will be generated in the same directory as the dest
file. By default it will have the same basename as the dest
file, but with a .map
extension.
sourceMapName
Type: String
Function
Default: undefined
To customize the name or location of the generated source map, pass a string to indicate where to write the source map to. If a function is provided, the uglify destination is passed as the argument and the return value will be used as the file name.
sourceMapIn
Type: String
Function
Default: undefined
The location of an input source map from an earlier compilation, e.g. from CoffeeScript. If a function is provided, the uglify source is passed as the argument and the return value will be used as the sourceMap name. This only makes sense when there's one source file.
sourceMapIncludeSources
Type: Boolean
Default: false
Pass this flag if you want to include the content of source files in the source map as sourcesContent property.
sourceMapRoot
Type: String
Default: undefined
With this option you can customize root URL that browser will use when looking for sources.
If the sources are not absolute URLs after prepending of the sourceMapRoot
, the sources are resolved relative to the source map.
enclose
Type: Object
Default: undefined
Wrap all of the code in a closure with a configurable arguments/parameters list.
Each key-value pair in the enclose
object is effectively an argument-parameter pair.
wrap
Type: String
Default: undefined
Wrap all of the code in a closure, an easy way to make sure nothing is leaking.
For variables that need to be public exports
and global
variables are made available.
The value of wrap is the global variable exports will be available as.
maxLineLen
Type: Number
Default: 32000
Limit the line length in symbols. Pass maxLineLen = 0 to disable this safety feature.
ASCIIOnly
Type: Boolean
Default: false
Enables to encode non-ASCII characters as \uXXXX.
exportAll
Type: Boolean
Default: false
When using wrap
this will make all global functions and variables available via the export variable.
preserveComments
Type: Boolean
String
Function
Default: undefined
Options: false
'all'
'some'
Turn on preservation of comments.
false
will strip all comments'all'
will preserve all comments in code blocks that have not been squashed or dropped'some'
will preserve all comments that start with a bang (!
) or include a closure compiler style directive (@preserve
@license
@cc_on
)Function
specify your own comment preservation function. You will be passed the current node and the current comment and are expected to return eithertrue
orfalse
banner
Type: String
Default: ''
This string will be prepended to the minified output. Template strings (e.g. <%= config.value %>
will be expanded automatically.
footer
Type: String
Default: ''
This string will be appended to the minified output. Template strings (e.g. <%= config.value %>
will be expanded automatically.
screwIE8
Type: Boolean
Default: false
Pass this flag if you don't care about full compliance with Internet Explorer 6-8 quirks.
mangleProperties
Type: Boolean
Default: false
Use this flag to turn on object property name mangling.
reserveDOMProperties
Type: Boolean
Default: false
Use this flag in conjunction with mangleProperties
to prevent built-in browser object properties from being mangled.
exceptionsFiles
Type: Array
Default: []
Use this with mangleProperties
to pass one or more JSON files containing a list of variables and object properties
that should not be mangled. See the UglifyJS docs for more info on the file syntax.
nameCache
Type: String
Default: ''
A string that is a path to a JSON cache file that uglify will create and use to coordinate symbol mangling between
multiple runs of uglify. Note: this generated file uses the same JSON format as the exceptionsFiles
files.
quoteStyle
Type: Integer
Default: 0
Preserve or enforce quotation mark style.
0
will use single or double quotes such as to minimize the number of bytes (prefers double quotes when both will do)1
will always use single quotes2
will always use double quotes3
will preserve original quotation marks
Usage examples
Basic compression
This configuration will compress and mangle the input files using the default options.
// Project configuration.
grunt.initConfig({
uglify: {
my_target: {
files: {
'dest/output.min.js': ['src/input1.js', 'src/input2.js']
}
}
}
});
No mangling
Specify mangle: false
to prevent changes to your variable and function names.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
mangle: false
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Reserved identifiers
You can specify identifiers to leave untouched with an except
array in the mangle
options.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
mangle: {
except: ['jQuery', 'Backbone']
}
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Source maps
Generate a source map by setting the sourceMap
option to true
. The generated
source map will be in the same directory as the destination file. Its name will be the
basename of the destination file with a .map
extension. Override these
defaults with the sourceMapName
attribute.
// Project configuration.
grunt.initConfig({
uglify: {
my_target: {
options: {
sourceMap: true,
sourceMapName: 'path/to/sourcemap.map'
},
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Advanced source maps
Set the sourceMapIncludeSources
option to true
to embed your sources directly into the map. To include
a source map from a previous compilation pass it as the value of the sourceMapIn
option.
// Project configuration.
grunt.initConfig({
uglify: {
my_target: {
options: {
sourceMap: true,
sourceMapIncludeSources: true,
sourceMapIn: 'example/coffeescript-sourcemap.js', // input sourcemap from a previous compilation
},
files: {
'dest/output.min.js': ['src/input.js'],
},
},
},
});
Refer to the UglifyJS SourceMap Documentation for more information.
Turn off console warnings
Specify drop_console: true
as part of the compress
options to discard calls to console.*
functions.
This will suppress warning messages in the console.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
compress: {
drop_console: true
}
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Beautify
Specify beautify: true
to beautify your code for debugging/troubleshooting purposes.
Pass an object to manually configure any other output options passed directly to UglifyJS.OutputStream()
.
See UglifyJS Codegen documentation for more information.
Note that manual configuration will require you to explicitly set beautify: true
if you want traditional, beautified output.
// Project configuration.
grunt.initConfig({
uglify: {
my_target: {
options: {
beautify: true
},
files: {
'dest/output.min.js': ['src/input.js']
}
},
my_advanced_target: {
options: {
beautify: {
width: 80,
beautify: true
}
},
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Banner comments
In this example, running grunt uglify:my_target
will prepend a banner created by interpolating the banner
template string with the config object. Here, those properties are the values imported from the package.json
file (which are available via the pkg
config property) plus today's date.
Note: you don't have to use an external JSON file. It's also valid to create the pkg
object inline in the config. That being said, if you already have a JSON file, you might as well reference it.
// Project configuration.
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
uglify: {
options: {
banner: '/*! <%= pkg.name %> - v<%= pkg.version %> - ' +
'<%= grunt.template.today("yyyy-mm-dd") %> */'
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Conditional compilation
You can also enable UglifyJS conditional compilation. This is commonly used to remove debug code blocks for production builds.
See UglifyJS global definitions documentation for more information.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
compress: {
global_defs: {
"DEBUG": false
},
dead_code: true
}
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Compiling all files in a folder dynamically
This configuration will compress and mangle the files dynamically.
// Project configuration.
grunt.initConfig({
uglify: {
my_target: {
files: [{
expand: true,
cwd: 'src/js',
src: '**/*.js',
dest: 'dest/js'
}]
}
}
});
Turn on object property name mangling
This configuration will turn on object property name mangling, but not mangle built-in browser object properties.
Additionally, variables and object properties listed in the myExceptionsFile.json
will be mangled. For more info,
on the format of the exception file format please see the UglifyJS docs.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
mangleProperties: true,
reserveDOMCache: true,
exceptionsFiles: [ 'myExceptionsFile.json' ]
},
my_target: {
files: {
'dest/output.min.js': ['src/input.js']
}
}
}
});
Turn on use of name mangling cache
Turn on use of name mangling cache to coordinate mangled symbols between outputted uglify files. uglify will the
generate a JSON cache file with the name provided in the options. Note: this generated file uses the same JSON format
as the exceptionsFiles
files.
// Project configuration.
grunt.initConfig({
uglify: {
options: {
nameCache: '.tmp/grunt-uglify-cache.json',
},
my_target: {
files: {
'dest/output1.min.js': ['src/input1.js'],
'dest/output2.min.js': ['src/input2.js']
}
}
}
});
Release History
- 2015-11-20 v0.11.0 switch to uglify ~2.6.0
- 2015-11-12 v0.10.1 switch to uglify ~2.5
- 2015-10-27 v0.10.0 bump to uglify ^2.5
- 2015-08-24 v0.9.2 bump to uglify ^2.4.24
- 2015-04-07 v0.9.1 more fixes for mangle options
- 2015-04-07 v0.9.0 added hook into uglify's mangling functionality
- 2015-03-30 v0.8.1 lock uglify to 2.4.17 due to breaking changes
- 2015-02-19 v0.8.0 Add
screwIE8
option. Fix issue with explicitcompress
in node 0.12.0. - 2014-12-23 v0.7.0 Adds sourceMapRoot options. Updates readme descriptions. Removes reference to cleancss.
- 2014-09-17 v0.6.0 Output fixes. ASCIIOnly option. Other fixes.
- 2014-07-25 v0.5.1 Chalk updates. Output updates.
- 2014-03-01 v0.4.0 remove grunt-lib-contrib dependency and add more colors
- 2014-02-27 v0.3.3 remove unnecessary calls to
grunt.template.process
- 2014-01-22 v0.3.2 fix handling of
sourceMapIncludeSources
option. - 2014-01-20 v0.3.1 fix relative path issue in sourcemaps
- 2014-01-16 v0.3.0 refactor sourcemap support
- 2013-11-09 v0.2.7 prepending banner if sourceMap option not set, addresses
- 2013-11-08 v0.2.6 merged 45, 53, 85 (105 by way of duping 53) Added support for banners in uglified files with sourcemaps Updated docs
- 2013-10-28 v0.2.5 Added warning for banners when using sourcemaps
- 2013-09-02 v0.2.4 updated sourcemap format via /83
- 2013-06-10 v0.2.3 added footer option
- 2013-05-31 v0.2.2 Reverted /56 due to /58 until chrome/239660 firefox/870361 drop
- 2013-05-22 v0.2.1 Bumped uglify to ~2.3.5 /55 /40 Changed sourcemappingUrl syntax /56 Disabled sorting of names for consistent mangling /44 Updated docs for sourceMapRoot /47 /25
- 2013-03-14 v0.2.0 No longer report gzip results by default. Support
report
option. - 2013-01-30 v0.1.2 Added better error reporting Support for dynamic names of multiple sourcemaps
- 2013-02-15 v0.1.1 First official release for Grunt 0.4.0.
- 2013-01-18 v0.1.1rc6 Updating grunt/gruntplugin dependencies to rc6. Changing in-development grunt/gruntplugin dependency versions from tilde version ranges to specific versions.
- 2013-01-09 v0.1.1rc5 Updating to work with grunt v0.4.0rc5. Switching back to this.files api.
- 2012-11-28 v0.1.0 Work in progress, not yet officially released.
Task submitted by "Cowboy" Ben Alman
This file was generated on Fri Nov 20 2015 14:05:29.