[GROOVY-10368] STC fails to instantiate type variable when using diamond operator

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.2
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 15/Nov/21 09:28
• Updated: 23/Jul/22 16:22
• Resolved: 15/Mar/22 15:08

Description

I have the following program

class A<T extends Number> {
  A(String x) {}
}


class B {
  void m(A<Integer> x) {}
}


class Test {
  void test() {
    B x = new B();
    x.m(new A<>(""));
  }
}

Actual behaviour

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 14: [Static type checking] - Cannot call B#m(A<java.lang.Integer>) with arguments [A<# extends java.lang.Number>]
 @ line 14, column 5.
       x.m(new A<>(""));
       ^

1 error

Expected behaviour

Compile successfully

Tested against master (https://github.com/apache/groovy/commit/cf2f77fb033a10d36c4db3a7ff07a2b04631afcf)