Add Less support to Yeoman Webapp generator - gruntjs

Question

I have project that started with yeoman webapp generator with out compass support.
Now i need to integrate some less files (Not bootstrap) to my app. I need to add them to grunt to compile them and minify in distribution. Is there any proper way to edit gruntfile to achieve this this?
My GruntFile is looks like
'use strict';
// # Globbing
// for performance reasons we're only matching one level down:
// 'test/spec/{,*/}*.js'
// If you want to recursively match all subfolders, use:
// 'test/spec/**/*.js'
module.exports = function (grunt) {
// Time how long tasks take. Can help when optimizing build times
require('time-grunt')(grunt);
// Automatically load required grunt tasks
require('jit-grunt')(grunt, {
useminPrepare: 'grunt-usemin'
});
// Configurable paths
var config = {
app: 'app',
dist: 'dist'
};
// Define the configuration for all the tasks
grunt.initConfig({
// Project settings
config: config,
// Watches files for changes and runs tasks based on the changed files
watch: {
bower: {
files: ['bower.json'],
tasks: ['wiredep']
},
babel: {
files: ['<%= config.app %>/scripts/{,*/}*.js'],
tasks: ['babel:dist']
},
babelTest: {
files: ['test/spec/{,*/}*.js'],
tasks: ['babel:test', 'test:watch']
},
gruntfile: {
files: ['Gruntfile.js']
},
sass: {
files: ['<%= config.app %>/styles/{,*/}*.{scss,sass}'],
tasks: ['sass:server', 'postcss']
},
styles: {
files: ['<%= config.app %>/styles/{,*/}*.css'],
tasks: ['newer:copy:styles', 'postcss']
}
},
browserSync: {
options: {
notify: false,
background: true
},
livereload: {
options: {
files: [
'<%= config.app %>/{,*/}*.html',
'.tmp/styles/{,*/}*.css',
'<%= config.app %>/images/{,*/}*',
'.tmp/scripts/{,*/}*.js'
],
port: 9000,
server: {
baseDir: ['.tmp', config.app],
routes: {
'/bower_components': './bower_components'
}
}
}
},
test: {
options: {
port: 9001,
open: false,
logLevel: 'silent',
host: 'localhost',
server: {
baseDir: ['.tmp', './test', config.app],
routes: {
'/bower_components': './bower_components'
}
}
}
},
dist: {
options: {
background: false,
server: '<%= config.dist %>'
}
}
},
// Empties folders to start fresh
clean: {
dist: {
files: [{
dot: true,
src: [
'.tmp',
'<%= config.dist %>/*',
'!<%= config.dist %>/.git*'
]
}]
},
server: '.tmp'
},
// Make sure code styles are up to par and there are no obvious mistakes
eslint: {
target: [
'Gruntfile.js',
'<%= config.app %>/scripts/{,*/}*.js',
'!<%= config.app %>/scripts/vendor/*',
'test/spec/{,*/}*.js'
]
},
// Mocha testing framework configuration options
mocha: {
all: {
options: {
run: true,
urls: ['http://<%= browserSync.test.options.host %>:<%= browserSync.test.options.port %>/index.html']
}
}
},
// Compiles ES6 with Babel
babel: {
options: {
sourceMap: true
},
dist: {
files: [{
expand: true,
cwd: '<%= config.app %>/scripts',
src: '{,*/}*.js',
dest: '.tmp/scripts',
ext: '.js'
}]
},
test: {
files: [{
expand: true,
cwd: 'test/spec',
src: '{,*/}*.js',
dest: '.tmp/spec',
ext: '.js'
}]
}
},
// Compiles Sass to CSS and generates necessary files if requested
sass: {
options: {
sourceMap: true,
sourceMapEmbed: true,
sourceMapContents: true,
includePaths: ['.']
},
dist: {
files: [{
expand: true,
cwd: '<%= config.app %>/styles',
src: ['*.{scss,sass}'],
dest: '.tmp/styles',
ext: '.css'
}]
},
server: {
files: [{
expand: true,
cwd: '<%= config.app %>/styles',
src: ['*.{scss,sass}'],
dest: '.tmp/styles',
ext: '.css'
}]
}
},
postcss: {
options: {
map: true,
processors: [
// Add vendor prefixed styles
require('autoprefixer-core')({
browsers: ['> 1%', 'last 2 versions', 'Firefox ESR', 'Opera 12.1']
})
]
},
dist: {
files: [{
expand: true,
cwd: '.tmp/styles/',
src: '{,*/}*.css',
dest: '.tmp/styles/'
}]
}
},
// Automatically inject Bower components into the HTML file
wiredep: {
app: {
src: ['<%= config.app %>/index.html'],
exclude: ['bootstrap.js'],
ignorePath: /^(\.\.\/)*\.\./
},
sass: {
src: ['<%= config.app %>/styles/{,*/}*.{scss,sass}'],
ignorePath: /^(\.\.\/)+/
}
},
// Renames files for browser caching purposes
filerev: {
dist: {
src: [
'<%= config.dist %>/scripts/{,*/}*.js',
'<%= config.dist %>/styles/{,*/}*.css',
'<%= config.dist %>/images/{,*/}*.*',
'<%= config.dist %>/styles/fonts/{,*/}*.*',
'<%= config.dist %>/*.{ico,png}'
]
}
},
// Reads HTML for usemin blocks to enable smart builds that automatically
// concat, minify and revision files. Creates configurations in memory so
// additional tasks can operate on them
useminPrepare: {
options: {
dest: '<%= config.dist %>'
},
html: '<%= config.app %>/index.html'
},
// Performs rewrites based on rev and the useminPrepare configuration
usemin: {
options: {
assetsDirs: [
'<%= config.dist %>',
'<%= config.dist %>/images',
'<%= config.dist %>/styles'
]
},
html: ['<%= config.dist %>/{,*/}*.html'],
css: ['<%= config.dist %>/styles/{,*/}*.css']
},
// The following *-min tasks produce minified files in the dist folder
imagemin: {
dist: {
files: [{
expand: true,
cwd: '<%= config.app %>/images',
src: '{,*/}*.{gif,jpeg,jpg,png}',
dest: '<%= config.dist %>/images'
}]
}
},
svgmin: {
dist: {
files: [{
expand: true,
cwd: '<%= config.app %>/images',
src: '{,*/}*.svg',
dest: '<%= config.dist %>/images'
}]
}
},
htmlmin: {
dist: {
options: {
collapseBooleanAttributes: true,
collapseWhitespace: true,
conservativeCollapse: true,
removeAttributeQuotes: true,
removeCommentsFromCDATA: true,
removeEmptyAttributes: true,
removeOptionalTags: true,
// true would impact styles with attribute selectors
removeRedundantAttributes: false,
useShortDoctype: true
},
files: [{
expand: true,
cwd: '<%= config.dist %>',
src: '{,*/}*.html',
dest: '<%= config.dist %>'
}]
}
},
// By default, your `index.html`'s <!-- Usemin block --> will take care
// of minification. These next options are pre-configured if you do not
// wish to use the Usemin blocks.
// cssmin: {
// dist: {
// files: {
// '<%= config.dist %>/styles/main.css': [
// '.tmp/styles/{,*/}*.css',
// '<%= config.app %>/styles/{,*/}*.css'
// ]
// }
// }
// },
// uglify: {
// dist: {
// files: {
// '<%= config.dist %>/scripts/scripts.js': [
// '<%= config.dist %>/scripts/scripts.js'
// ]
// }
// }
// },
// concat: {
// dist: {}
// },
// Copies remaining files to places other tasks can use
copy: {
dist: {
files: [{
expand: true,
dot: true,
cwd: '<%= config.app %>',
dest: '<%= config.dist %>',
src: [
'*.{ico,png,txt}',
'images/{,*/}*.webp',
'{,*/}*.html',
'styles/fonts/{,*/}*.*'
]
}, {
expand: true,
dot: true,
cwd: '.',
src: 'bower_components/bootstrap-sass/assets/fonts/bootstrap/*',
dest: '<%= config.dist %>'
}]
}
},
// Run some tasks in parallel to speed up build process
concurrent: {
server: [
'babel:dist',
'sass:server'
],
test: [
'babel'
],
dist: [
'babel',
'sass',
'imagemin',
'svgmin'
]
}
});
grunt.registerTask('serve', 'start the server and preview your app', function (target) {
if (target === 'dist') {
return grunt.task.run(['build', 'browserSync:dist']);
}
grunt.task.run([
'clean:server',
'wiredep',
'concurrent:server',
'postcss',
'browserSync:livereload',
'watch'
]);
});
grunt.registerTask('server', function (target) {
grunt.log.warn('The `server` task has been deprecated. Use `grunt serve` to start a server.');
grunt.task.run([target ? ('serve:' + target) : 'serve']);
});
grunt.registerTask('test', function (target) {
if (target !== 'watch') {
grunt.task.run([
'clean:server',
'concurrent:test',
'postcss'
]);
}
grunt.task.run([
'browserSync:test',
'mocha'
]);
});
grunt.registerTask('build', [
'clean:dist',
'wiredep',
'useminPrepare',
'concurrent:dist',
'postcss',
'concat',
'cssmin',
'uglify',
'copy:dist',
'filerev',
'usemin',
'htmlmin'
]);
grunt.registerTask('default', [
'newer:eslint',
'test',
'build'
]);
};

Answer 1

You will need to install the grunt-contrib-less task and then add the configuration similar to the following, to your gruntfile.js.
less: {
development: {
options: {
paths: ["assets/css"]
},
files: {
"path/to/result.css": "path/to/source.less"
}
}
}
To then minify your css, take a look at grunt-contrib-cssmin which you can configure something like:
cssmin: {
options: {
shorthandCompacting: false,
roundingPrecision: -1
},
target: {
files: {
'output.css': ['foo.css', 'bar.css']
}
}
}
To load these tasks add:
grunt.loadNpmTasks('grunt-contrib-less');
grunt.loadNpmTasks('grunt-contrib-cssmin');
and if you want to have them both run under one task:
grunt.registerTask('lessmin', ['less', 'cssmin']);
Which you can run from the command line with:
grunt lessmin