Imports to the pipeline all the CSS assets included with url().
npm install gulp-extract-css-urls --save-dev
import gulp from 'gulp';
import extractCssUrls from 'gulp-extract-css-urls';
// This will copy main.css along with its resources loaded with url().
gulp.task('default', () => {
return gulp.src('main.css', { cwd: 'resources/assets/css/' })
.pipe(extractCssUrls())
.pipe(gulp.dest('public/assets/'));
});