[GROOVY-11307] Compiler error for misapplication of @FunctionalInterface

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Compiler
• Assignee: Unassigned
• Reporter: Eric Milles
• Created: 05/Feb/24 20:36
• Updated: 05/Feb/24 20:36

Description

groovyc does not emit errors for misuse of @FunctionalInterface. At minimum an interface with 0 or 2+ abstract methods should be an error. Bonus points for supporting traits as well – a trait compiles to an interface. And using the annotation on a class, enum or @interface is improper as well.

@FunctionalInterface
interface I {
}