code: function watch() {
    gulp.watch([appSrc + '/app/**/*.ts', '!' + appSrc + '/app/**/*.spec.ts']).on('change', function (e) {
      console.log('TypeScript file ' + e.path + ' has been changed. Compiling.');
    });
    gulp.watch([appSrc + '/app/**/*.less']).on('change', function (e) {
      console.log(e.path + ' has been changed. Updating.');
      transpileLESS(e.path);
      updateWatchDist();
    });
    gulp.watch([appSrc + '/app/**/*.html']).on('change', function (e) {
      console.log(e.path + ' has been changed. Updating.');
      copyToDist(e.path);
      updateWatchDist();
    });
  }
docs: Watch
   Watch source