Testing Section Improvements

[GeorgeMac]

What I think we need to add in order to feel that testing is complete for now.

• mocking and interfaces
• integration testing
• code reuse (i.e. to avoid it where possible)
• fixtures in tests
• naming conventions for tests

Please contribute to this Issue thread so that we can track here the topics we want to talk about.

[brettbuddin]

📎 https://rakyll.org/naming-tests-to-doc/

Naming of tests is important. We should converge on some naming conventions for tests and subtests.

I've made the mistake that Hashimoto described in his talk regarding indices as names: https://github.com/brettbuddin/musictheory/blob/master/chord_test.go. This was pre-Subtest code, but you get the idea. I'd like to avoid that kind of behavior in the future.

[GeorgeMac]

Currently the consensus is we do not use mocking libraries.

We feel that we are equipped with everything we need, via just using interfaces + structs.

The section on mocking should document this practice.

[GeorgeMac]

Opened PR #12 to cover mocking discussion