Mix font-awesome compile error

".copy" code error for Webpack.mix.js.

//I use

mix.js('resources/js/app.js', 'public/js')
    .sourceMaps()
    .copy('node_modules/font-awesome/fonts/', 'public/fonts')
    .sass('resources/sass/app.scss', 'public/css').version();

What I've done before;

//console
npm install font-awesome

//added in resources/assets/sass/app.scss
@import "node_modules/font-awesome/scss/font-awesome";

//in the webpack.mix file
.copy('node_modules/font-awesome/fonts', 'public/fonts');

Works for "npm run dev". Returns error for "npm run watch". "Error chokidar"