Normal functions are defined as follows:

function doSomething () {
    // ...
}

Normal anonymous functions are defined as follows:

() => {
    // ...
}

Asynchronous functions are defined by adding the async keyword:

async function doSomething () {
    // ...
}

We can also make anonymous functions asynchronous:

async () => {
    // ...
}

Within async functions, we can use the await keyword to resolve promises. We do not have to do the following anymore:

() => {
    fetchAPITodos()
        .then(todos => dispatch({ type: FETCH_TODOS, todos }))
}

Instead, we can now do this:

async () => {
    const todos = await fetchAPITodos()
    dispatch({ type: FETCH_TODOS, todos })
}

As we can see, async functions make our code much more concise and easier to read! Now that we have learned about the async/await construct, we can start testing the useDebouncedUndo Hook.