gulpfile.js

const gulp = require('gulp');
const sass = require('gulp-sass')(require('sass'));
const cssnano = require('gulp-cssnano');
const rev = require('gulp-rev');
const uglify = require('gulp-uglify-es').default;
const imagemin = require('gulp-imagemin');
const del = require('del');

gulp.task('css', function(done) {
	console.log('minifying css...');
	gulp.src('./assets/scss/**/*.scss').pipe(sass()).pipe(cssnano()).pipe(gulp.dest('./assets.css'));

	gulp
		.src('./assets/**/*.css')
		.pipe(rev())
		.pipe(gulp.dest('./public/assets'))
		.pipe(
			rev.manifest('rev-manifest.json', {
				base  : 'public',
				cwd   : 'public',
				merge : true
			})
		)
		.pipe(gulp.dest('./public/assets'));
	done();
});

gulp.task('js', function(done) {
	console.log('minifying js...');
	gulp
		.src('./assets/**/*.js')
		.pipe(uglify())
		.pipe(rev())
		.pipe(gulp.dest('./public/assets'))
		.pipe(
			rev.manifest({
				cwd   : 'public',
				merge : true
			})
		)
		.pipe(gulp.dest('./public/assets'));
	done();
});

gulp.task('images', function(done) {
	console.log('compressing images...');
	gulp
		.src('./assets/**/*.+(png|jpg|gif|svg|jpeg)')
		.pipe(imagemin())
		.pipe(rev())
		.pipe(gulp.dest('./public/assets'))
		.pipe(
			rev.manifest({
				cwd   : 'public',
				merge : true
			})
		)
		.pipe(gulp.dest('./public/assets'));
	done();
});

// empty the public/assets directory
gulp.task('clean:assets', function(done) {
	del.sync('./public/assets/css');
	del.sync('./public/assets/js');
	del.sync('./public/assets/rev-manifest.json');
	done();
});

gulp.task('build', gulp.series('clean:assets', 'js', 'css'), function(done) {
	console.log('Building assets');
	done();
});