Watching new files

[Plou]

The easy way is to upgrade to gulp 4:

# global
npm upgrade -g gulp-cli

# local (each project)
npm uninstall gulp --save-dev
 npm install 'gulpjs/gulp.git#4.0' --save-dev

The task and watch system changes a bit, so the upgraded gulpfile.js looks like that:

// gulpfile.js
[...]

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

    browserSync.init({
        server: "./",
        open: false,
    })
    let watcher = {
      scss : gulp.watch('css/src/**/*.scss'),
      js : gulp.watch('js/src/**/*.js'),
      pug : gulp.watch('templates/**/*.pug'),
      img : gulp.watch('img/**/*')
    }

    watcher.scss.on('all', gulp.parallel('scss'))
    watcher.js.on('all', gulp.parallel('js'))
    watcher.pug.on('all', gulp.parallel('pug'))
    watcher.img.on('all', gulp.parallel(browserSync.reload))


    gulp.parallel('scss')
})

gulp.task('build', gulp.parallel('pug', 'scss', 'js'))
gulp.task('default', gulp.parallel('build', 'serve'))