tentacat VS mimic

In my opinion, Mock works well for certain types of tests. I usually find myself reaching for it when we need to mock external libraries that we have no control over. For example, let’s say we use an external library to fetch a user’s GitHub profile instead of our custom GithubAPI. Something like this:

If you are used to Mocha for other languages, you can check out Mimic. It lets you define stubs and expectations during tests by keeping track of the stubbed module in an ETS table.

By adjusting the mindset to stop thinking about dependencies and start to think about behaviours (functions) we were able to extract the impure parts of the number generator function. Then, by making them injectable we transformed the impure function to the one into which we can inject purity in tests, making it essentially pure and thus much easier to test. We also didn't need any fancy tool like Mox, Mimic or Rewire to define replacement modules for us. The code is hopefully understandable and uses only built-in Elixir idioms, without macros.

Check out https://github.com/edgurgel/mimic for mocking purposes