Matching a generic method

[triceo]

In my Java code, I have an interface X<A> with the following method:

default <Y_ extends Y<Y_>> @NonNull Z<A, Y_> doSomething(@NonNull Y_ constraintWeight);

I am trying to write a pattern that would match this method. I have this, which should work, but doesn't:

fully.qualified.X doSomething(fully.qualified.Y)

I've been racking my brain as to why the above doesn't match the method. (It doesn't match anything.) And then, in desperation, I tried to use the specific implementation of Y (let's call it YImpl) which I actually use in the test for the recipe:

fully.qualified.X doSomething(fully.qualified.YImpl)

And suddenly, the pattern started matching.

So, my question is: how do I get the pattern to match on the generic type Y, and therefore get it to rewrite any code using that method, not just code that uses YImpl?

[timtebeek]

That sounds like we have a problem either in setting up that type attribution on the method, or subsequently matching it. Did you attach a debugger to see what the type is on that method invocation that fails to match?

As a workaround, is doSomething specific enough that you could use fully.qualified.X doSomething(..) and then figure out the rest in your visitor after that initial match?

[triceo]

Thanks for the answer!

I have been debugging this - and it is doSomething(fully.qualified.Yimpl), where Yimpl is an implementation of Y interface.

I did try the .. approach, but unfortunately, this matches too many other methods. But yeah, I may be able to filter it out in the visitor after that, good point.

[timtebeek]

Thanks for letting us know; sounds like it's indeed the type attribution on the method invocation then that needs a fix here, as that ought to take the type of the method declaration, not whatever types happened to be passed in as arguments, even with generics (I think). Would you like to provide a reproducer on a draft PR to kick that off? Or log an issue based on the above with this link?
https://github.com/openrewrite/rewrite/issues/new?created_from_discussion_number=5038

[triceo]

• Methods with generic arguments are not matched #5047

I simplified the description so that it's hopefully easier to reproduce - that said, I have not provided a code reproducer. If one is absolutely necessary, I can give access to my code, where the issue would show up. (But that would by no means be a minimal reproducer, and therefore I think it reading through it may cost more time than it saves.)