sass.js

var gulp = require('gulp'),
	$ = require('gulp-load-plugins')({ lazy: true }),
	autoprefixer = require('autoprefixer'),
	rucksack = require('rucksack-css'),
	bourbon = require('node-bourbon'),
    neat = require('node-neat'),
    lost = require('lost');

var paths = require('../../paths.js'),
	config = require('../../config.js')();

gulp.task('sass', function() {
	var env = ((config.environment || process.env.NODE_ENV || 'development').trim().toLowerCase() !== 'production'),

	sass = {
        sourceComments: (config.sassOptions.sourceComments).trim().toLowerCase() ? !env : '',
        outputStyle: (config.sassOptions.outputStyle).trim().toLowerCase() ? !env : 'compressed',
        imagePath: config.sassOptions.imagePath,
        precision: config.sassOptions.precision || 3,
        includePaths: [
            bourbon.includePaths,
			neat.includePaths
        ],
        errLogToConsole: true
    },
    plugins = [
        lost(),
        rucksack(),
        autoprefixer({
            browsers: [
                '> 1%',
                'last 2 versions',
                'firefox >= 4',
                'safari 7',
                'safari 8',
                'IE 8',
                'IE 9',
                'IE 10',
                'IE 11'
            ],
        }),
	];

	console.log('-> Compiling SASS for ' + config.environment);

	if (env) {
		// Select files
		gulp.src(`${paths.to.sass.in}/*.scss`)
		// Prevent pipe breaking caused by errors from gulp plugins
		.pipe($.plumber())
		// Initialize sourcemaps
		.pipe($.sourcemaps.init())
		// Compile Sass
		.pipe($.sass(sass).on('error', $.sass.logError))
		// Add vendor prefixes
		.pipe($.postcss(plugins))
		// Concatenate includes
		.pipe($.include({
			includePaths: [
				`${config.root}/bower_components`,
				`${config.root}/node_modules`
			],
		}))
		// save sourcemaps
		.pipe($.sourcemaps.write(paths.to.sass.out))
		// Save unminified file
		.pipe(gulp.dest(`${paths.to.sass.out}`))
	} else {
		// Select files
		gulp.src(`${paths.to.sass.in}/*.scss`)
		// Prevent pipe breaking caused by errors from gulp plugins
		.pipe($.plumber())
		// Compile Sass
		.pipe($.sass(sass).on('error', $.sass.logError))
		// Add vendor prefixes
		.pipe($.postcss(plugins))
		// Concatenate includes
		.pipe($.include({
			includePaths: [
				`${config.root}/bower_components`,
				`${config.root}/node_modules`
			],
		}))
		// Show file-size before compression
		.pipe($.size({ title: 'sass In Size' }))
		// Optimize and minify
		.pipe($.cssnano())
		// Show file-size after compression
		.pipe($.size({ title: 'sass Out Size' }))
		// Append suffix
		.pipe($.rename({
			suffix: '.min',
		}))
		// Save minified file
		.pipe(gulp.dest(`${paths.to.sass.out}`))
	}
});