Intellij Idea warning – “Promise returned is ignored” with aysnc/await

The userController.login() function returns a promise, but you’re not doing anything with the result from the promise by utilizing its then() function.

For example:

userController.login(req, res).then(() => {
    // Do something after login is successful.
});

or in the ES2017 syntax:

await userController.login(req, res);

If you don’t actually want to do anything there, I guess you can just ignore the warning. The warning is mostly there because not using the then() function on a promise is usually a code smell.