Am 28.08.19 um 16:48 schrieb Daimona: >> Subclassing should be very limited anyway, and even more limited across > module >> boundaries > > I agree, but it doesn't offer a strict guarantee.
Do we need a strict guarantee more than we need unit tests? >> which could even be enforced via static analysis. > > Why not just use final, then? Because it makes it impossible to write unit tests. Maybe not impossible with the tool you pointed to. If that thing works, it becomes: it requires effort to set up the CI infrastructure to allow this to work, and we don't know who is going to do that, or when. >> Method contracts should be enforced by compliance tests. When following > these principles, making >> methods and classes final has little benefit. > > Ideally, yes. But I don't think our codebase has enough tests for that. That's what we are trying to fix, and final stuff is making it hard. >> Preventing mocking is however a pretty massive cost. > > Definitely yes. But making methods mockable while also keeping the > capability to use finals is even better IMHO. If that can be made to work, sure. I'm just saying that an inability to mock far outweights the potential benefits of declaring things as final. > In theory, for sure. But I believe there are lots of occurrences in our > code where static methods are not pure functions. Which indeed is one of the things we are currently trying to fix, because static code can't be mocked. >> with these contracts. Final methods make callers rely on a specific >> implementation, which may still end up changing anyway. > > Two sides of a coin, I think. Each of them has its benefits and its > drawbacks, I'd say. What benefits does it have to bind to a specific implementation that is not guaranteed to stay as it is? >> If I understand correctly, this would break as soon as the mock object > hits a >> type hint of instanceof check. That won't fly. > > No, that's only what happens with mockery. The tool I found just strips > 'final' keywords from the PHP code - I believe, I still haven't looked at > the implementation. If somebody is volunteering to do the necessary work in the CI infrastructure, fine. To me it just seems like just removing the final modifier is the easier and cheaper solution, and doesn't have any big downside. -- Daniel Kinzler Principal Software Engineer, Core Platform Wikimedia Foundation _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
