Unnecessary
return await function found JS-0111
Performance
Major
3 years ago
—
3 years old
Redundant use of
await on a return value117}) {
118 const [handleSubmit, isPending] = useStripeSession();
119 const handleOnClick = async () =>
120 await handleSubmit({121 amount: actionCost,122 cause: cause,123 });124 return (
125 <div
126 className={`pt-5 ${
Description
Returning an awaited value (like with return await f()) has two problems:
It queues an extra microtask, blocking the callstack until
returnis executed.tryblocks only catch a rejected promise if itsawaited.return awaitmay introduce unexpected hidden control-flow when handling errors.
Bad Practice
async function getUserByName(name: string) {
// find() returns a Promise<User | null >.
// This promise should be `await`ed by the caller of `getUserByName`.
return await db.users.find({ userName: name })
}
Recommended
async function getUserByName(name: string) {
// find() returns a Promise<User | null >.
return db.users.find({ userName: name })
}
// OR:
async function getUserByName(name: string) {
// If we must `await` the return-value in this function
// it's better to do it this way. This is more performant:
const user = await db.users.find({ userName: name })
return user;
}