I have not found a good way to grunt-uglify multiple script files spread over multiple folders while keeping the folder structure including the uglified files intact. The on
Similar to the answer by @DioNNiS, but stores minified files in the same folder:
uglify: { all: { files: [{ expand: true, cwd: 'path/to/js/', src: ['*.js', '!*.min.js'], dest: 'path/to/js/', ext: '.min.js' }] } }