Does the Resolve step wait until the task is done?

It's the other way around, resolve uses a microtask, and queue a task uses a regular task, so we can guarantee that the callback attached in requestSession(..).resolve(callback) will execute before the task below does.

ok. Resolve actually calls the then function. I think this looks good!

Yep!

er, i should have written then instead of resolve in my comment above, but you get the idea