配置：

uglify: {
	options: {
		mangle: {
			//toplevel: true,
			screw_ie8: true

		},
		compress: {
			screw_ie8: true,
			sequences: true,
			//properties: true,
			dead_code: true,
			drop_debugger: true,
			comparisons: true,
			conditionals: true,
			evaluate: true,
			booleans: true,
			loops: true,
			unused: true,
			hoist_funs: true,
			if_return: true,
			join_vars: true,
			cascade: true,
			//negate_iife: true,
			drop_console: true
		}
	},
	main: {
		src: ['src/main.js'],
		dest: 'dist/main.min.js'
	}
},

运行

uglifyjs --self -c -m -o /tmp/uglifyjs.js