[GROOVY-8164] Groovy allows a Java class to inherit static methods from its interface

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.7
• Fix Version/s: 4.0.0-rc-2, 3.0.18
• Component/s: Compiler, Static compilation
• Labels: breaking
• Assignee: Eric Milles
• Reporter: Dmitry Khamitov
• Created: 24/Apr/17 20:34
• Updated: 06/Jan/24 14:55
• Resolved: 13/Dec/21 20:59

Description

In the following situation Java doesn't compile (as per JLS8 - 8.4.8 Inheritance, Overriding, and Hiding):

interface Foo {
  static void foo() {
    System.out.println("static void foo() called");
  }
}

class Bar implements Foo { }

public class FooBarTest {
    public static void main(String[] args) {
        Bar.foo();
    }
}

$ javac FooBarTest.java
FooBarTest.java:3: error: cannot find symbol
        Bar.foo();
           ^
  symbol:   method foo()
  location: class Bar
1 error

But Groovy does compile, both dynamic and @CompileStatic and we get static void foo() called in the output

Just in case, here is a snippet from JLS8:
8.4.8 Inheritance, Overriding, and Hiding
A class C inherits from its direct superclass all concrete methods m (both static and instance) of the superclass for which all of the following are true:
...
A class does not inherit static methods from its superinterfaces.

Issue Links

• causes: GROOVY-10504 Cannot call static method from Java interface (Groovy 4)
• causes: GROOVY-10590 Static methods of interfaces are not resolved anymore in implementig classes with Groovy 4.x
• causes: GROOVY-10605 Regression of method argument resolution with Groovy 4
• causes: GROOVY-11268 MissingMethodException for java Function<>
• is related to: GROOVY-11107 EnumSet varargs constructor is not recognized (broken) in runtime