@copilot please add tests for this function - currently a hook named "tach" is not registered and you should be able to get a failing test.

Originally posted by @nathanjmcdougall in #1639

We should update the agent skills to reflect the principle that we should aim for complete coverage on each module independently of the others, i.e. we shouldn't rely on the end-to-end tests, and should try to have complete unit tests.