My question is: Is it okay to pass a promise to the first argument of .then? (Assuming that I'm not interested in the returned value of the previous promise and I just want to chain promises together).
Someone told me that if I do this, a new promise will be created implicitly (unnecessarily), and I might face issues handling errors bellow in the promise chain.
I know that if you don't explicitly return a promise in an async method the result will be implicitly wrapped. In this case, .then should not wrap the argument in a promise since the argument is already a promise :/
Example:
async function asyncFunc() {
//async function (return Promise)
}
// I know this is okay
somePromise.then(() => asyncFunc());
// BUT... is this okay?
somePromise.then(asyncFunc());Is it okay to pass a promise to the first argument of
.then?
Yes.
Someone told me that if I do this, a new promise will be created implicitly (unnecessarily)
Promise.prototype.then() returns a new promise either way.
// BUT... is this okay? somePromise.then(asyncFunc());
No, it is more or less the same as:
const p = asyncFunc()
somePromise.then(p);
You execute the function before somePromise actually resolves. What you probably want instead is somePromise.then(asyncFunction). This will properly chain the promises after each other.
Someone told me that [...] I might face issues handling errors bellow in the promise chain.
No. This does not change the behaviour of the promise chain as long as long as there is a catch at the end of the chain.