withLoadingScreen First pass

withLoadingScreen-1.js

import * as React from "react";
import { View, ActivityIndicator } from "react-native";

const withLoadingScreen = WrappedComponent => {
  return class LoadingScreen extends React.PureComponent {
    render() {
      if (this.props.loading) return <ActivityIndicator size="small" color="white" />
      return <WrappedComponent {...this.props} />;
    }
  };
};

export default withLoadingScreen;

if in render function it's not a good practice (for my opinion) do somthing like this (if you dont have state....):

import * as React from "react";
import { View, ActivityIndicator } from "react-native";

export default const withLoadingScreen = ({loading})=> ( loading ? : <WrappedComponent {...this.props} />);