[GROOVY-10614] Fail to infer the correct type argument when having conditionals and diamond operator

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 30/Apr/22 20:07
• Updated: 15/Apr/23 17:26

Description

I think this is a regression bug, because Groovy 4.0.2 compiles the program successfully.

class Foo<T> {}

class Test {
  public static void test() {
    foo((true) ? new Foo<Boolean>() : new Foo<>());
    
  }

  public static void foo(Foo<Boolean> x) {}
  
}

Actual behaviour

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 5: [Static type checking] - Cannot call Test#foo(Foo<java.lang.Boolean>) with arguments [Foo<? extends java.lang.Object>]
 @ line 5, column 5.
       foo((true) ? new Foo<Boolean>() : new Foo<>());
       ^

1 error

Expected Behaviour

Compile successfully

Tested against master (commit: e183dc8e04a8ca8762e85e21ac3ee0c03138b6e1)

Issue Links

• is related to: GROOVY-10114 Wrong type argument inference when using the result of ternary operator directly.