Testing API calls in PHP with Guzzle Mocks

I'm working on a CouchDB library for PHP, and so I needed to write some tests for it. CouchDB has an HTTP API so I'm basically making web requests and while I could certainly set up a test database and run full-on integration tests, there are a few limitations with that approach. Firstly: it means I'm testing the database as well, which isn't what I want and brings extra dependencies that make the tests harder to run. Also: I want to be able to test error cases, rate limiting and so on, that would be difficult to recreate reliably. Continue reading