How to do functional testing of an expressjs API?

what's the best way to functional test an express API call the endpoint and verify expected changes were made and expected actions taken.

eg. a call with value 'yes' to Api sms/entry ( a twilio web hook ) should: - check user status - order and charge ( thru stripe ) - send response thru twilio API what's a good approach to functional test that? note I'm not interested in testing the http response.

initial thoughts - use nock to intercept http calls to twilio and stripe - use supertest to call endpoint and use mongoose to verify new application state after call ( supertest callback )

we already some unit tests, we aiming for a more high level functional test of the API

"Unit tests tell a developer that the code is doing things right; functional tests tell a developer that the code is doing the right things."