[GROOVY-8360] Enums that are nested classes do not have the static modifier set

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.x, 2.6.0-alpha-1, 2.4.12, 2.5.0-beta-2
• Fix Version/s: 2.5.0-beta-3
• Component/s: Compiler
• Assignee: Shil Sinha
• Reporter: Shil Sinha
• Created: 20/Oct/17 00:11
• Updated: 06/Mar/18 23:25
• Resolved: 13/Nov/17 03:47

Description

In java, enums that are nested classes have the static modifier set i.e. if Bar is an enum defined within a class Foo, assert Modifier.isStatic(Foo.Bar.modifiers) passes. The assertion does not hold if Foo and Bar are defined in groovy:

class Foo {
    enum Bar {
        X
    }
}
            
assert java.lang.reflect.Modifier.isStatic(Foo.Bar.modifiers)

This can be problematic in cases like https://mongodb.github.io/morphia/, where the type of a mapped field cannot be a non-static inner class. Of course that library could also be more enum-aware when validating mapped fields, but that's a separate issue.

A simple workaround for this issue is to explicitly declare the enum as static, so it's not critical that a patch for this be in 2.4.X if it's considered a breaking change (though no tests fail with the change.)

Issue Links

• links to: GitHub Pull Request #619