EN/FR react-intl messages

gistfile1.js

// https://stackoverflow.com/questions/49104657/is-it-possible-to-override-locale-of-one-specific-intl-formatmessage/49275604?noredirect=1#comment85596893_49275604

import { defineMessages } from 'react-intl';

const messages = defineMessages({
  hello: {
    id: 'app.hello',
    defaultMessage: 'Hello in english',
  }
}

fr.messages.json:

{
  "app.hello": "Hello in french"
}