async function or async => when exporting default?

Question

export default async function () {  }; 

or

export default async () => {  }; 

Which one is preferred when exporting a default function and why?

Answer 1

The first one is generally preferred. It's a declaration, not an expression value, which has subtle advantages. And it can easily be named if you want, which is a good practice. Also, arrow functions have a few disadvantages in certain situations, so unless you absolutely need them to preserve a this value (etc.) you'd rather avoid them. Saving 5 characters to type is hardly worth it.