fetch to request a JSON file and that will only happen at runtime. Furthermore, webpack only processes anything that is imported. You expected it to handle an argument to a function, but if webpack did that, every argument to a function would be considered a module and that breaks any other use for that function.
If you want your loaders to kick in, you can import the file.
You can also import the JSON and use it directly instead of fetching it a runtime. Webpack 2 uses
json-loader by default for all
.json files. You should remove the
.json rule and you would import the JSON as follows.
import menu from './portal/content/json/menu.json';