# Dig Deeper

Advanced topics and deeper insights for using Font Awesome with React.

> You can take Font Awesome with React to the next level by learning a little more about the behind-the-scenes stuff that we do to load icons and fine-tuning it to exactly what you need.

## Unit Testing

When testing components, you'll want to make sure that any icons referenced in those components are available for testing purposes. You have a couple choices here:

1. If you want to test a child component on its own, you can import its icons explicitly.
1. If you've built a library instead, and your test doesn't include your root component that defines your library of icons, you may see errors like this:

```js
Could not find icon { prefix: 'fas', iconName: 'chevron-right' }
```

If this happens, and the icon isn't important to the particular test, you can mock FontAwesomeIcon like this:

```jsx
import React from 'react'

export function FontAwesomeIcon(props) {
  return <i className="fa"></i>
}
```

With `create-react-app`, you can put this code in `src/__mocks__/@fortawesome/react-fontawesome.js` to automatically include it in any tests, and alleviate errors.

  <h4>
    The Font Awesome Javascript API
  </h4>

Are you hungry for more knowledge? You can deep dive into our [Font Awesome SVG Core](/web/dig-deeper/svg-core.md) and
[Javascript API docs](/apis/javascript.md).