I've been writing a lot of unit tests lately and have become somewhat obsessed with code coverage. However, I'm struggling justifying going for 100% code coverage, when so many tests would be a redundant, and really clutter up my unit tests.
For example, imagine an customer endpoint of an API. The user posts a customer ID, their location and then some data. Looks like
Here's an example of a code coverage snippet from instanbul, I'm using Node.js:
The first miss, failing to update the customer, is something that should definitely be tested. But the last 2, failing to find location and customer, are present on nearly every endpoint. Am I really to pass in an incorrect location, and then an incorrect customer, for every one of the endpoints (create, update, delete, etc.)? Or should I just live with those not being covered?