6 ms·

You wouldn't write a unit test to assert an object implements a method. You would test if the method works as expected. This will of course also fail if the met

• sanderjd 10y ago
  Here's a concrete example: say you are writing a test for a method that takes an object and asks that object some question, eg. `object.is_something()`. You can either explicitly assert that `object` implements `is_something` or just let it throw the normal error if it doesn't. Either way, you should test the functionality of the method when it receives an object that does not implement that method, because the behavior in that case is visible to callers, may come to be relied upon, and may cause a regression if changed. I find that lots of tests end up being of this sort, that I'm uncomfortable if I don't write them, that they clutter up test files and obscure the more interesting tests, and that they are exactly what type checking catches automatically.