Pray

React asynchronous components:

// Books.js
import React from 'react';
import pray from 'pray';

// Wrap the async component in pray:
export default pray(async () => {
  const books = await fetch('/books').then(res => res.json());

  return (
    <ul>
      {books.map(book => <li>{book.title}</li>)}
    </ul>
  )
});

Then in your main code import and use it as usual:

// App.js
import React from 'react';
import Books from './Books';

export default () => (
  <Books />
);

Spinner

You can add a spinner for whenever the main component is still loading:

//
const Spinner = () => 'Loading...';

// Note that we pass the component, not the instance:
export default pray(Spinner, async () => {
  ...
});

You can also assign it on render time:

// App.js
const Spinner = () => "Loading...";

// We again pass the component, not the instance:
export default () => (
  <Books fallback={Spinner} />
);

Props

Props will be passed as expected:

// Book.js
export default pray(async ({ id }) => {
  const book = await fetch(`/books/${id}`).then(res => res.json());
  return <div>{book.title}</div>;
});

// App.js
export default () => <Book id={123} />;

None of the Hooks can be used within async components. Please call those above and pass them as props:

const Books = pray(async ({ onLoad }) => {
  const books = await fetch('/books').then(res => res.json());
  onLoad(books);
  return (
    <ul>
      {books.map(book => <li>{book.title}</li>)}
    </ul>
  )
});

const BookList = () => {
  const [books, setBooks] = useState(null);
  return (
    <div>
      Book count: {books.length}
      <Books fallback={() => 'Loading...'} onLoad={setBooks} />
    </div>
  );
};