Gulp 4 browsersync does not refresh when changing .less file

Question

Link to Github repo: https://github.com/Greatshock/Netcracker-Study-Course/blob/f9bfb413929feec51064a78abf1450845f867186

I have a file named base.less, where all the styles are @import-ed. When I run the gulpfile (npm run dev), everything is being built, the browser opens the page. However, when I'm changing the content of one of the imported stylesheet, browsersync just writes in the console File event [change] : dist/base.css and nothing happens (even base.css does not actually change). Note that if I change base.less directly by writing some style in it, everything works fine.

Here is my gulpfile.js. Can anyone see the mistake?

'use strict';

const gulp         = require('gulp'),
      del          = require('del'),
      autoprefixer = require('gulp-autoprefixer'),
      less         = require('gulp-less'),
      cleanCSS     = require('gulp-clean-css'),
      gulpIf       = require('gulp-if'),
      sourceMaps   = require('gulp-sourcemaps'),
      browserSync  = require('browser-sync').create();

const isDevelopment = !process.env.NODE_ENV || process.env.NODE_ENV == 'development';

gulp.task('less', () => {
    return gulp.src('src/assets/themes/base/base.less')
        .pipe(gulpIf(isDevelopment, sourceMaps.init()))
        .pipe(less())
        .on('error', onLessError)
        .pipe(autoprefixer({
            browsers: [
                'last 2 versions',
                'safari 5',
                'ie 10',
                'ie 11'
            ],
            cascade: true
        }))
        .pipe(cleanCSS())
        .pipe(gulpIf(isDevelopment, sourceMaps.write()))
        .pipe(gulp.dest('prod'));
});

gulp.task('images', () => {
    return gulp.src('src/assets/themes/base/images/**/*.*', {base: 'src/assets/themes/base', since: gulp.lastRun('images')})
        .pipe(gulp.dest('prod'));
});

gulp.task('index', () => {
    return gulp.src('src/index.html', {since: gulp.lastRun('index')})
        .pipe(gulp.dest('prod'));
});

gulp.task('clean', () => {
    return del('prod');
});

gulp.task('build', gulp.series('clean', gulp.parallel('less', 'images', 'index')));

gulp.task('watch', () => {
    gulp.watch('src/assets/themes/base/**/*.less', gulp.series('less'));
    gulp.watch('src/assets/themes/base/images/**/*.*', gulp.series('images'));
    gulp.watch('src/index.html', gulp.series('index'));
});

gulp.task('serve', function() {

    browserSync.init({
        server: 'prod'
    });

    browserSync.watch('prod/**/*.*').on('change', browserSync.reload);
});

gulp.task('dev', gulp.series('build', gulp.parallel('watch', 'serve')));

/***HELPERS FUNCTIONS***/
function onLessError(error) {
    console.error(error.message);
    this.emit('end');
}

Answer 1

I don't like this hackaround because to me it says one of our plugins isn't working correctly (browser-sync) so we correct it with that broken plugin. I'd maybe try browserify instead.

gulp.task('serve', function() {

browserSync.init({
    files: [
        {
            match: ['src/assets/themes/base/**/*.less'],
            fn:    function (event, file) {
                this.reload()
            }
        }
    ],
    server: 'prod'
});

browserSync.watch('prod/**/*.*').on('change', browserSync.reload);
});

edit - This could also be a dir issue where the src is different than the watch dir. src/assets/themes/base/**/*.less' should be src/assets/themes/**/*.less' or src/assets/themes/base/*.less' for a distinct folder.

Edit 2- gulp.watch('src/assets/themes/base/*.less', gulp.series('less')); reloads base.less when any other file is changed if added to the gulp command. :D