gulpfile.js

'use strict';

let gulp       = require( 'gulp' ),
	rename     = require( 'gulp-rename' ),
	sass       = require( 'gulp-sass' )( require( 'node-sass' ) ),
	sourcemaps = require( 'gulp-sourcemaps' ),
	cssmin     = require( 'gulp-clean-css' ),
	uglify     = require( 'gulp-uglify-es' ).default;

gulp.task(
	'css:build',
	function () {
		return gulp.src( './assets/css/*.scss' )
		.pipe( sourcemaps.init() )
		.pipe( sass().on( 'error', sass.logError ) )
		.pipe( gulp.dest( './assets/css' ) )
		.pipe( cssmin() )
		.pipe(
			rename(
				{
					suffix: '.min',
				}
			)
		)
		.pipe( sourcemaps.write( '.' ) )
		.pipe( gulp.dest( './assets/css' ) );
	}
);

gulp.task(
	'css:build:watch',
	function () {
		gulp.watch( './assets/css/*.scss', gulp.parallel( 'css:build' ) );
	}
);

gulp.task(
	'js:build',
	function () {
		return gulp.src( ['./assets/js/*.js', '!./assets/js/*.min.js'] )
		.pipe( sourcemaps.init() )
		.pipe( uglify() )
		.pipe(
			rename(
				function (path) {
					path.extname = '.min.js';
				}
			)
		)
		.pipe( sourcemaps.write( '.' ) )
		.pipe( gulp.dest( './assets/js' ) );
	}
);

gulp.task(
	'js:build:watch',
	function () {
		gulp.watch( './assets/js/*.js', gulp.parallel( 'js:build' ) );
	}
);