Learning Unit Testing VI – Code Coverage

Before I get into finally finishing off that blasted page 10, I thought I’d go through a code coverage run to see how I was doing. Test Driven Development, see, everything should be covered by a test.


7.41% of the code is not covered by tests! I must be doing this wrong…


Phew, that was a relief. Turns out all of that uncovered code is in the WrongPhaseException I created from the Exception snippit without thinking about it. Activating the code coverage colouring in the code shows me what I’ve missed:


Because I only use one constructor out of a possible four, it counts as only 25% coverage and brings my average code coverage way down.

If I was to remove all those extra constructors (and leave them to the default Exception behaviour), would it improve my code coverage score?


Absolutely. It might be a bit like cheating (those methods are still not covered by tests), but since they’re core parts of the framework it doesn’t feel necessary to me. Short and sweet, on to part VII!

This is a learning project I am documenting in order to teach myself TDD and unit testing – as I publish this, I have already written many parts in advance but I want to know what I’m doing wrong! If you see improvements or corrections, either to the code or the process, please leave a comment and let me know! Introduction to this project can be found here.

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