Grunt ( not written because src files were empty )

module.exports = function(grunt) {
    grunt.loadNpmTasks('grunt-contrib-uglify');
    grunt.initConfig({
        uglify: {
            my_target: {
                files: {
                    '_s/js/script.js': ['_s/components/js/*.js','_s/components/js/other.js']
                }
            }
        }
    })
}

files/

d- components  
   f- script.js ->
     function test(){
       return "Hello";
    }
d- css 
d- js
   script.js -> 

f- node_modules   
f- gruntfile.js 
f- index.html  
package.json  

I'm write in file _s/components/js/script.js but when i'm try turn on in terminal command grunt uglify. i've been this error

>> Destination (_s/js/script.js) not written because src files were empty.

Done, without errors.

Sorry! I'm decided my

files: {
                    'js/script.js': ['components/js/*.js']
                }