Many naturally occurring processes are accurately modeled by priority queues. Single people maintain a priority queue of potential dating candidates – mentally if not explicitly. One’s impression on meeting a new person maps directly to an attractiveness or desirability score. Desirability serves as the key field for inserting this new entry into the “little black book” priority queue data structure. Dating is the process of extracting the most desirable person from the data structure (Finding-Maximum), spending an evening to evaluate them better, and then reinserting them into the priority queue with a possibly revised score.
I recently handed in an assignment on testing. It was fairly simple, and I expected it to take just a couple of hours and not teach me anything. That was not the case. I really think that every situation is an opportunity to learn something (even if it’s not what you think you will).
Lesson 1: JUnit 4 is awesome. Parametrized testing is a huge improvement.
Lesson 2: Twitter is an incredible source of knowledge. OK, I knew this, but a guy who I have books by responding to a random question is incredibly cool (or, I’m a giant nerd. Whatever).
Lesson 3: It’s important to design your test suite well. We started with 20 test cases, the purpose of which was to test one function, but 5 of them were really testing the constructor. It was clear to me that by well designing a test suite (from the spec, not the code) I could get better coverage with half as many test cases (of course, with parametrized testing this is not such a terrible thing).
Lesson 4: Coverage is seductive. I got a little caught up trying to get 100% coverage, adding tests to exercise paths in the code, rather than aspects of the specification.
Lesson 5: No amount of testing will fix bad design. After I’d written all my tests, I noted that it wasn’t really necessary to test simple get and set methods and lack of coverage there wasn’t really an issue. Then, I looked more closely and realized that those methods (that I hadn’t tested), however trivial, shouldn’t be there at all. The class was modeling a date object, and the tests were to make sure that invalid dates couldn’t be generated. But, using these simple set methods I could easily make invalid dates. Really, the class should have been immutable – but no amount of testing will point that out.
Cookie Consent
We use cookies to improve your experience on our site. By using our site, you consent to cookies.
