What problem are you facing?

The 4.0.1 TS typings' overloaded declarations for Collection.rename() has a | void on the return type of an overload that should only return a Promise. If a method returns a Promise, it should never also be typed | void. The problem doesn't show up in any other overload declarations, so I assume this was just a bug, not an implied assertion about weird behavior of this method.

I opened a PR to fix it: https://github.com/mongodb/node-mongodb-native/pull/2922

Code is here: https://github.com/mongodb/node-mongodb-native/blob/dc6e2d6c5762ec62d1096a52d670b76b02aa2bf3/src/collection.ts#L624

Expected: 

rename(newName: string, options: RenameOptions): Promise<Collection> | void;

Actual: 

rename(newName: string, options: RenameOptions): Promise<Collection>;

What driver and relevant dependency versions are you using?

4.0.1

Steps to reproduce?

See https://github.com/mongodb/node-mongodb-native/pull/2922