fetch data example

fetch.js

...
if (action.type !== LOCATION_CHANGE) {
  return;
}
const route = getRoute(action.payload.pathname);

try {
  const [result] = await Promise.all([
    fetcher.getPage(parsedUrl.pathname, { params: parsedUrl.params }), 
    route.component.preload()
  ]);  
} catch (e) {
  processError(e);
  return;
}

injectData(result);
return result;