Jest: Connection pool closed

Sometimes you want to wait until a method deep in the hierarchy has finished executing before completing the test. I was getting the following error:

MongoRuntimeError: The connection pool has been closed.

I’m working on a booking system that sends SMS notifications; the problem is that it’s an async method, and jest always finishes before the endpoint is complete.

To correct this error, I mocked my notification library:

…and I used this library to handle the waiting until my method completed its execution.

https://www.npmjs.com/package/wait-for-expect

Elegant and simple.