gulpfile.js

const gulp = require('gulp');
const sass = require('gulp-sass');
const cssImport = require('gulp-cssimport');
const cssBase64 = require('gulp-css-base64');
const concat = require('gulp-concat');

const task = gulp.task;
const src = gulp.src;
const dest = gulp.dest;

task('sass', function () {
    return gulp.src('./material/scss/style.scss')
        .pipe(sass())
        .on('error', function (err) {
            console.log(err.toString());
            this.emit('end');
        })
        .pipe(cssImport())
        // ~ this rebases URLs incorrectly ~ //
        //.pipe(concat('sass.css'))
        .pipe(dest('./material/scss/sass.css'));
});

task('import-sass-css', function () {
    return src('./material/scss/style.scss')
        .pipe(sass())
        .pipe(cssImport())
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(concat('stylesheet.css'))
        .pipe(dest('./assets/gulped/final/'));
});

task('mergecss', function () {
    return src(['./material/css/animate.css', './material/css/form.css', './material/css/spinners.css', './material/css/style.css'])
        .pipe(cssImport())
        .pipe(concat('stylesheet.css'))
        .pipe(dest('./assets/gulped/'));
});


task('icons/fa', function () {
    return src('./material/css/icons/font-awesome/css/fontawesome-all.css')
        .pipe(concat('fa.css'))
        .pipe(cssBase64({
            maxWeightResource: 163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/linea', function () {
    return src('./material/css/icons/linea-icons/linea.css')
        .pipe(concat('linea.css'))
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/materialdesign', function () {
    return src('./material/css/icons/material-design-iconic-font/css/*.css')
        .pipe(concat('material-design.css'))
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/simpleline', function () {
    return src('./material/css/icons/simple-line-icons/css/simple-line-icons.css')
        .pipe(concat('simple-line.css'))
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/themify', function () {
    return src('./material/css/icons/themify-icons/themify-icons.css')
        .pipe(concat('themify.css'))
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/weather', function () {
    return src(['./material/css/icons/weather-icons/css/weather-icons-wind.min.css', './material/css/icons/weather-icons/css/weather-icons.min.css'])
        .pipe(concat('weather.css'))
        .pipe(cssBase64({
            maxWeightResource: 1163840
        }))
        .pipe(dest('./assets/gulped/icons/'));
});

task('icons/concat', function () {
    return src('./assets/gulped/icons/*.css')
        .pipe(concat('icons.css'))
        .pipe(dest('./assets/gulped/icons/final/'));
});