Update Gruntfile.js

Gruntfile.js

@@ -1,61 +1,56 @@
-/*global module:false*/
-module.exports = function(grunt){
+module.exports = function (grunt) {
+  const srcFiles = 'src/**/*.js';
+  const distDir = 'dist/';
 
-
-	// Project configuration.
-	grunt.initConfig({
-		pkg: grunt.file.readJSON('package.json'),
-		bower: grunt.file.readJSON('bower.json'),
-		copy: {
-			demo: {
-				files: [
-					{expand: true, src: ['src/*'], dest: 'dist/', filter: 'isFile', flatten: true}
-				]
-			}
-		},
+  grunt.initConfig({
+    pkg: grunt.file.readJSON('package.json'),
+    bower: grunt.file.readJSON('bower.json'),
 
-		uglify: {
-			options: {
-				beautify: {
-					ascii_only : true
-				},
-				preserveComments: 'some'
-			},
-			html5shiv: {
-				files: [{
-					expand: true,     // Enable dynamic expansion.
-					cwd: 'src/',      // Src matches are relative to this path.
-					src: ['**/*.js'], // Actual pattern(s) to match.
-					dest: 'dist/',   // Destination path prefix.
-					ext: '.min.js'
-				}]
-			}
-		},
-		watch: {
-			js: {
-				files: ['src/**/*.js'],
-				tasks: ['copy', 'uglify', 'bytesize']
-			}
-		},
-		bytesize: {
-			all: {
-				src: [
-					'dist/**.min.js'
-				]
-			}
-		}
-	});
+    copy: {
+      demo: {
+        files: [
+          { expand: true, cwd: 'src/', src: ['*'], dest: distDir, flatten: true }
+        ]
+      }
+    },
 
-
-	// Default task.
+    uglify: {
+      options: {
+        beautify: { ascii_only: true },
+        preserveComments: 'some'
+      },
+      html5shiv: {
+        files: [{
+          expand: true,
+          cwd: 'src/',
+          src: ['**/*.js'],
+          dest: distDir,
+          ext: '.min.js'
+        }]
+      }
+    },
 
-
+    watch: {
+      js: {
+        files: [srcFiles],
+        tasks: ['copy', 'uglify', 'bytesize']
+      }
+    },
 
-	grunt.loadNpmTasks('grunt-contrib-copy');
-	grunt.loadNpmTasks('grunt-contrib-uglify');
-	grunt.loadNpmTasks('grunt-contrib-watch');
-	grunt.loadNpmTasks('grunt-bytesize');
+    bytesize: {
+      all: {
+        src: [`${distDir}*.min.js`]
+      }
+    }
+  });
 
-	grunt.registerTask('default', ['copy', 'uglify', 'bytesize', 'watch']);
+  [
+    'grunt-contrib-copy',
+    'grunt-contrib-uglify',
+    'grunt-contrib-watch',
+    'grunt-bytesize'
+  ].forEach(task => grunt.loadNpmTasks(task));
 
+  grunt.registerTask('default', ['copy', 'uglify', 'bytesize']);
+  grunt.registerTask('dev', ['default', 'watch']);
 };