gulpfile.js

const gulp = require('gulp');
const less = require('gulp-less');
const cleanCSS = require('gulp-clean-css');

/* ----------------------------------------- */
/*  Handle Errors function
/* ----------------------------------------- */

function handleError(err) {
  console.log(err.toString());
  this.emit('end');
}

/* ----------------------------------------- */
/*  Compile LESS
/* ----------------------------------------- */

const T2K_LESS = ['less/**/*.less'];

function compileLESS() {
  return gulp
    .src('./less/t2k4e.less')
    .pipe(less().on('error', handleError))
    .pipe(cleanCSS({ debug: true }, details => {
      console.log(`${details.name}: ${details.stats.originalSize}`);
      console.log(`${details.name}: ${details.stats.minifiedSize}`);
    }))
    .pipe(gulp.dest('./'));
}
const css = gulp.series(compileLESS);

/* ----------------------------------------- */
/*  Watch Updates
/* ----------------------------------------- */

function watchUpdates() {
  gulp.watch(T2K_LESS, css);
}

/* ----------------------------------------- */
/*  Export Tasks
/* ----------------------------------------- */

exports.default = gulp.series(
  gulp.parallel(css),
  watchUpdates,
);
exports.css = css;