FindMethods cannot find arguments for subclasses

[seachicken]

I want to use org.openrewrite.java.search.FindMethods to search for code where an arbitrary class is set as the argument to String.valueOf(), to investigate the impact of changing the toString result.
I am running the recipe below, but the latter, java.lang.String valueOf(com.example.Foo), does not match.

# rewrite.yml
---
type: specs.openrewrite.org/v1beta/recipe
name: com.yourorg.FindMethodsExample
displayName: Find method usages example
recipeList:
  - org.openrewrite.java.search.FindMethods:
      methodPattern: com.example.Foo toString()
  - org.openrewrite.java.search.FindMethods:
      methodPattern: java.lang.String valueOf(com.example.Foo)

The MethodMatcher argument check compares it with String.valueOf(java.lang.Object), so it does not appear to match String.valueOf(com.example.Foo).
In my use case, it would be useful to be able to detect the use of subclasses of Object. Are there any alternative ways to do this?

[knutwannheden]

In the method matcher pattern you have to write the pattern in a way such that it matches the declaration signature: java.lang.String valueOf(java.lang.Object). If you also want it to match the other overloads of this method for the primitive types, you can use java.lang.String valueOf(*)

[seachicken]

Thanks! The method matcher pattern alone cannot be used to detect it. Is there a way to detect the Foo class of the argument using an existing recipe?

[knutwannheden]

If you only want to find invocations of String#valueOf() where the argument is of type com.example.Foo, then I think you will have to write a custom recipe for that. That should however be pretty easy to build on top of MethodMatcher by doing additional filtering. So similar to the existing FindMethods recipe.

[seachicken]

Thank you, I will try making the recipe.

[seachicken]

Just sharing. I then learned that filters can be combined in "preconditions", so the below method seems to work well in my case, although it also gives some false positives:

 # rewrite.yml
---
type: specs.openrewrite.org/v1beta/recipe
name: com.yourorg.FindMethods
preconditions:
  - com.yourorg.FindTypes
recipeList:
  - org.openrewrite.java.search.FindMethods:
      methodPattern: java.lang.Object toString()
      matchOverrides: true
  # Find implicit toString() calls
  - org.openrewrite.java.search.FindMethods:
      methodPattern: java.lang.String valueOf(*)
  - org.openrewrite.java.search.FindMethods:
      methodPattern: java.lang.StringBuilder append(..)
  - org.openrewrite.text.Find:
      find: +
---
type: specs.openrewrite.org/v1beta/recipe
name: com.yourorg.FindTypes
recipeList:
  - org.openrewrite.java.search.FindTypes:
      fullyQualifiedTypeName: com.example.Foo
      checkAssignability: true
  - org.openrewrite.java.search.FindTypes:
      fullyQualifiedTypeName: com.example.Bar
      checkAssignability: true