[GROOVY-10698] Fail to infer the type argument when using nested diamond operator

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.5, 3.0.20
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 21/Jul/22 07:47
• Updated: 11/Dec/23 19:19
• Resolved: 24/Jul/22 16:55

Description

I have the following program

class A<T> {
  A(T x, B<T> y) {}
}

class B<X> {}


class Test {
  void test() {
    new A<>("fda", new B<>())
  }
}

Actual behavior

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 10: [Static type checking] - Cannot call A#<init>(java.lang.Object, B<java.lang.Object>) with arguments [java.lang.String, B<T>]
 @ line 10, column 5.
       new A<>("fda", new B<>())
       ^

1 error

Expected behavior

Compile successfully.

Tested against master (commit: 63bcab1bf13fb3811626fb1727c22e86528feb7f)

*Notes:*

• this bug occurs when the type parameters of class A and B involve different names
• this bug is not triggered is groovy 4.0.2. It is introduced in groovy 4.0.3.