Adding "clean source" task to gulp file

gulpfile.js

@@ -39,6 +39,7 @@ var clone = require('gulp-clone');
 var merge = require('gulp-merge');
 var sourcemaps = require('gulp-sourcemaps');
 var browserSync = require('browser-sync').create();
+var del = require('del');
 
 
 // Run:
@@ -160,13 +161,16 @@ gulp.task('scripts', function() {
     .pipe(gulp.dest('./js/'));
 });
 
+gulp.task('clean-source', function () {
+  return del(['src/**/*',]);
+});
 
 // Run:
 // gulp copy-assets.
 // Copy all needed dependency assets files from bower_component assets to themes /js, /scss and /fonts folder. Run this task after bower install or bower update
 
 ////////////////// All Bootstrap SASS  Assets /////////////////////////
-gulp.task('copy-assets', function() {
+gulp.task('copy-assets', ['clean-source'], function() {
 
 ////////////////// All Bootstrap 4 Assets /////////////////////////
 // Copy all Bootstrap JS files

package.json

@@ -6,7 +6,6 @@
   "scripts": {
     "postinstall": "gulp copy-assets"
   },
-
   "repository": {
     "type": "git",
     "url": "https://github.com/holger1411/understrap.git"
@@ -27,6 +26,7 @@
   "dependencies": {
     "bootstrap": "^4.0.0-alpha.6",
     "browser-sync": "^2.18.5",
+    "del": "^2.2.2",
     "font-awesome": "^4.7.0",
     "gulp": "^3.9.1",
     "gulp-clone": "^1.0.0",