[GROOVY-7015] Groovy static type checking doesn't solve the generic types properly (behavior is different than Java)

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.4
• Fix Version/s: 2.3.8, 2.4.0-beta-4
• Component/s: Static Type Checker
• Assignee: Jochen Theodorou
• Reporter: Harminder Singh
• Created: 08/Aug/14 08:46
• Updated: 17/Dec/14 13:25
• Resolved: 13/Nov/14 09:00

Description

In the following code, the type of myVar variable is of type Base instead of Derived. This behavior is different than Java.

class Base {}
class Derived extends Base {
  public void sayHello() {
    System.out.println("hello");
  }
}

class GBase<T extends Base>{
  T myVar;
}
@CompileStatic
class GDerived extends GBase<Derived>
{
  GDerived() { myVar = new Derived(); }
  public void method() {
    // Groovy compiler thinks myVar is of type base and doesn't have sayHello
    myVar.sayHello();
  }
}

public class Main
{
  public static void main(String[] args)
  {
    GDerived d = new GDerived();
    d.method();
  }
}