[GROOVY-10633] Invalid type substitution when encountering bounded type parameter and the diamond operator

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.4, 2.5.21, 3.0.15
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 20/May/22 11:21
• Updated: 12/Jan/23 20:43
• Resolved: 21/Jun/22 15:11

Description

This bug is a regression.

I have the following program:

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

class B<T> {
  void m(T x) {}
}

class Test {
  <T extends Number> void test() {
    def x = new B<T>();
    new A<>(x, "").f.m((T) null);
  }
}

Actual behavior

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 13: [Static type checking] - Cannot find matching method B#m(T). Please check if the declared type is correct and if the method exists.
 @ line 13, column 5.
       new A<>(x, "").f.m((T) null);
       ^

1 error

Expected behaviour

Compile successfully

Tested against master (commit: a976ecdee1f17f7fafc55767de2d857c44d44697)

Issue Links

• relates to: GROOVY-10662 Fail to substitute type variable when encountering conflicting type parameter with a bound