File to watch and compile less files in (./css) folder and compile es6 file using babel in (./js/*/*-es6.js) folder with mentioned ending letters . On starting the script the files are compiled once . You can also individually compile just less or es6 files .

gulpfile.js

// Automate front end processes
// TODO
// 1) use npm plugin angular template cache to generate cache of either the html or the jsp files
var less = require('gulp-less');
var path = require('path');
var gulp = require('gulp');
var minifyCSS = require('gulp-minify-css');
var watch = require('gulp-watch');
var babel = require('gulp-babel');



gulp.task('watch-less-es6', function () {
	
    
	watchLess() ;
	
    // whenever any file in the js folder or direct subfolder of js having -es6.js in its name
    watchES6() ;
});

// just watch the less files
function watchLess() {
	
	watch('./css/*.less', function () {

    	complileLessFile();

	
    });
}

// just watch the es6 files
gulp.task('watch-es6' , function() {
	
	watchES6() ;
})

function watchES6() {
	
	 watch( './js/*/*-es6.js' , function() {
	    	
	    	compileES6() ;
	    	
	    });
	
}

function compileES6() {
	
	return gulp.src(['./js/*-es6.js' , './js/*/*-es6.js'] , { base : './'})
		.pipe( babel({
			presets : ['es2015']
		}))
		.pipe(gulp.dest('./js/compiled'));
	
}

function complileLessFile() {
	
	gulp.src('./css/*.less')
	  .pipe(less())
	  .pipe(minifyCSS())
	  .pipe(gulp.dest('./css/compiled/'));
}

// compile the less file once on start of the command
complileLessFile();
compileES6() ;