Parsing error: Unexpected token = (at line 1)

_loadResourcesAsync.js

  _loadResourcesAsync = async () => {
    return Promise.all([
      Asset.loadAsync([
        require('./assets/images/robot-dev.png'),
        require('./assets/images/robot-prod.png'),
      ]),
      Font.loadAsync({
        // This is the font that we are using for our tab bar
        ...Ionicons.font,
        // We include SpaceMono because we use it in HomeScreen.js. Feel free
        // to remove this if you are not using it in your app
        'space-mono': require('./assets/fonts/SpaceMono-Regular.ttf'),
        'Roboto': require('native-base/Fonts/Roboto.ttf'),
        'Roboto_medium': require('native-base/Fonts/Roboto_medium.ttf'),        
      }),
    ]);
  };