Use RxJS exhaustMap to Wait for Open Combos to Finish Before Starting New Ones

In this lesson, we'll be looking at an issue with our combo implementation: given that we're switchMapping to a new inner combo each time the user presses the combo initiation key (the letter "a" in our example), if the initiation key is found anywhere in the middle of the combo, it will just cancel out any on-going inner combos.

To fix it, we'll look at the differences between switchMap and exhaustMap and why exhaustMap is a much better choice for our scenario: switchMap disposes of any previous inner observables when it gets a new notification from the source, while exhaustMap waits for the inner observable to finish, before considering any new notifications from the source.