Как генерировать css(scss) в gulp?

const gulp = require('gulp'),
	sass = require('gulp-sass'),
	autoprefixer = require('gulp-autoprefixer'),
	cssnano = require('gulp-cssnano');

gulp.task('scss', () => {
	return gulp
	.src('dec/scss/**/*.scss')
	.pipe(sass())
	.pipe(
		autoprefixer(['last 15 version', '> 1%', 'ie 8', 'ie 7'], {
			cascade: true
		})
	)
	.pipe(cssnano())
	.pipe(gulp.dest('dist/css'));
});

gulp.task('default', gulp.series('scss'), () => {
	gulp.watch('dev/sass/**/*.scss', ['scss']);
});

[10:56:39] Using gulpfile /var/www/html/gulpfile.js
[10:56:39] Starting 'default'...
[10:56:39] Starting 'scss'...
[10:56:39] Finished 'scss' after 32 ms
[10:56:39] Finished 'default' after 38 ms