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    3.0.0 • Public • Published

    grunt-contrib-less v3.0.0 Build Status

    Compile LESS files to CSS

    Getting Started

    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-less --save-dev

    Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:


    This plugin was designed to work with Grunt 0.4.x. If you're still using grunt v0.3.x it's strongly recommended that you upgrade, but in case you can't please use v0.3.2.

    Less task

    Run this task with the grunt less command.

    Task targets, files and options may be specified according to the grunt Configuring tasks guide.



    Type: String Array Function
    Default: Directory of input file.

    Specifies directories to scan for @import directives when parsing. Default value is the directory of the source, which is probably what you want.

    If you specify a function the source filepath will be the first argument. You can return either a string or an array of paths to be used.


    Type: String
    Default: ""

    A path to add on to the start of every URL resource.


    Type: Boolean
    Default: false

    Compress output by removing some whitespaces.


    Type: Array
    Default: null

    Allows passing plugins.


    Type: Integer
    Default: null

    Set the parser's optimization level. The lower the number, the less nodes it will create in the tree. This could matter for debugging, or if you want to access the individual nodes in the tree.


    Type: Boolean
    Default: false

    Force evaluation of imports.


    Type: Boolean
    Default: false

    When enabled, math is required to be in parenthesis.


    Type: Boolean
    Default: false

    When enabled, less will validate the units used (e.g. 4px/2px = 2, not 2px and 4em/2px throws an error).


    Type: Boolean
    Default: false

    Read @import'ed files synchronously from disk.


    Type: String
    Default: false

    Configures -sass-debug-info support.

    Accepts following values: comments, mediaquery, all.


    Type: Boolean
    Default: false

    Rewrite URLs to be relative. false: do not modify URLs.


    Type: Object
    Default: none

    Define custom functions to be available within your LESS stylesheets. The function's name must be lowercase. In the definition, the first argument is the less object, and subsequent arguments are from the less function call. Values passed to the function are types defined within less, the return value may be either one of them or primitive. See the LESS documentation for more information on the available types.


    Type: Boolean
    Default: false

    Enable source maps.


    Type: String
    Default: none

    Write the source map to a separate file with the given filename.


    Type: String
    Default: none

    Override the default URL that points to the source map from the compiled CSS file.


    Type: String
    Default: none

    Sets the base path for the less file paths in the source map.


    Type: String
    Default: none

    Adds this path onto the less file paths in the source map.


    Type: Boolean
    Default: false

    Puts the map (and any less files) as a base64 data uri into the output css file.


    Type: Boolean
    Default: false

    Puts the less files into the map instead of referencing them.


    Type: Object
    Default: none

    Overrides global variables. Equivalent to --modify-vars='VAR=VALUE' option in less.


    Type: String
    Default: none


    Type: Function(content, destinationPath) Default: none Attributes: content, destinationPath

    Allows to parse the CSS content to be written to destinationPath to flow through a self defined function.

    Usage Examples

    less: {
      development: {
        options: {
          paths: ['assets/css']
        files: {
          'path/to/result.css': 'path/to/source.less'
      production: {
        options: {
          paths: ['assets/css'],
          plugins: [
            new (require('less-plugin-autoprefix'))({browsers: ["last 2 versions"]}),
            new (require('less-plugin-clean-css'))(cleanCssOptions)
          modifyVars: {
            imgPath: '""',
            bgColor: 'red'
        files: {
          'path/to/result.css': 'path/to/source.less'

    Release History

    • 2021-02-21   v3.0.0   Updated to Less 4. ieCompat option removed.
    • 2021-02-20   v2.1.0   Dependency updates. New process option to modify the written CSS.
    • 2018-05-25   v2.0.0   Update less to ^3.0.0
    • 2017-03-08   v1.4.1   Fix sourceMappingURL to be the same as the CSS if not specified, #322. Rethrow the compilation error after printing the message, #315.
    • 2016-07-21   v1.4.0   Update async and less to ~2.7.1.
    • 2016-04-07   v1.3.0   Update lodash and async dependecies.
    • 2016-02-01   v1.2.0   Update to less ~2.6.0. Removed peerDependency from package.json.
    • 2015-11-09   v1.1.0   Update to less ~2.5.0.
    • 2014-12-23   v1.0.0   Update to less 2.1.0.
    • 2014-10-23   v0.12.0   Added cleancssOptions as an option. When possible, includes filename for failed writes. Ensure banner only outputs on the first file in a series.
    • 2014-07-29   v0.11.4   Fix banner and urlArgs LESS options. Fixes npm 2 peerDependencies issues.
    • 2014-06-20   v0.11.3   Update to Less ~1.7.2.
    • 2014-06-01   v0.11.2   Lock to less 1.7.0.
    • 2014-05-26   v0.11.1   Fix modifyVars to work when less file ends with a comment.
    • 2014-03-19   v0.11.0   Custom functions can return types defined by less. paths option now accepts a function. Replaced deprecated grunt.util methods. Removes deprecated grunt.lib.contrib.
    • 2014-03-01   v0.10.0   sourceMapBasepath accepts a function. Update copyright to 2014. Update .gitattributes. Update less.js to v1.7.0. Prevent CRLF in the repo. Adds modify-vars option. Changed to async stack call. Fixes data-uri test. Normalize line endings on tests.
    • 2014-01-07   v0.9.0   Bump to less 1.6.
    • 2013-12-06   v0.8.3   Support sourceMapURL.
    • 2013-11-14   v0.8.2   Support outputSourceFiles.
    • 2013-10-24   v0.8.1   Support sourceMapFilename, sourceMapBasepath and sourceMapRootpath.
    • 2013-10-22   v0.8.0   Upgrade to LESS 1.5. Support strictUnits option. Support sourceMap option. Add customFunctions option for defining custom functions within LESS. Output the source file name on error. yuicompress option now cleancss (Less changed underlying dependency)
    • 2013-08-08   v0.7.0   Downgrade no source files warning to only in verbose mode.
    • 2013-08-08   v0.6.5   Support strictMath option. Support rootpath parse option.
    • 2013-07-09   v0.6.4   Support relativeUrls option.
    • 2013-07-06   v0.6.3   Add report option for minification and gzip results.
    • 2013-07-03   v0.6.2   support syncImport.
    • 2013-06-12   v0.6.1   Support ieCompat.
    • 2013-06-09   v0.6.0   Bump less to 1.4.0.
    • 2013-05-23   v0.5.2   Improve error handling.
    • 2013-04-25   v0.5.1   Gracefully handle configuration without sources.
    • 2013-02-15   v0.5.0   First official release for Grunt 0.4.0.
    • 2013-01-23   v0.5.0rc7   Updating grunt/gruntplugin dependencies to rc7. Changing in-development grunt/gruntplugin dependency versions from tilde version ranges to specific versions. Remove experimental wildcard destination support. Switching to this.files API.
    • 2012-10-18   v0.3.2   Add support for dumpLineNumbers.
    • 2012-10-12   v0.3.1   Rename grunt-contrib-lib dep to grunt-lib-contrib.
    • 2012-09-24   v0.3.0   Global options depreciated. Revert normalize linefeeds.
    • 2012-09-16   v0.2.2   Support all less options. Normalize linefeeds. Default path to dirname of src file.
    • 2012-09-10   v0.2.0   Refactored from grunt-contrib into individual repo.

    Task submitted by Tyler Kellen

    This file was generated on Sun Feb 21 2021 11:29:25.



    npm i grunt-contrib-less

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