[GROOVY-9259] Implementing Groovy interface with default methods can cause compile issues.

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.0-beta-3
• Fix Version/s: 3.0.10, 4.0.1
• Assignee: Eric Milles
• Reporter: covers1624
• Created: 27/Sep/19 13:02
• Updated: 23/Jul/22 16:20
• Resolved: 19/Feb/22 23:04

Description

Hello!

Consider the following classes.

test/JavaInterface.java

package test;

public interface JavaInterface {

    String doStuff();
}

test/GroovyInterface.groovy

package test

interface GroovyInterface extends JavaInterface {

    default doOtherStuff() {
        return 'doot'
    }
}

test/GroovyClass.groovy

package test

class GroovyClass implements GroovyInterface {
    @Override
    String doStuff() {
        return "otherDoot"
    }
}

This code compiles with an error:

test/GroovyClass.groovy: 4: Method 'doStuff' from class 'test.GroovyClass' does not override method from its superclass or interfaces but is annotated with @Override.
 @ line 4, column 5.
       @Override
       ^

However, removing the default method inside _{GroovyInterface}, OR, declaring _GroovyClass to implement both _{GroovyInterface} AND _{JavaInterface} will make compilation succeed again.

Apologies if this is some form of intended behavior, although I suspect it isn't due to the nature of this issue.

Thank You for your time looking into this issue! also thanks for a fantastically flexible language!

Issue Links

• is related to: GROOVY-8299 Generate bytecode for interface with default, private and static methods