[GROOVY-7843] Trait method calling closure cannot be inherited while using CompileStatic

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 4.0.0-alpha-1, 3.0.6
• Assignee: Eric Milles
• Reporter: Arnaud CAVAILHEZ
• Created: 22/May/16 19:00
• Updated: 11/Nov/20 02:00
• Resolved: 10/Aug/20 13:54

Description

A trait extending another and calling itself more than 3 times:

@CompileStatic
trait UpperTrait {
    void call(Closure body){
        body()
    }
}

@CompileStatic
trait LowerTrait extends UpperTrait {

    void threeCalls() {
        call {
            call {
                call {

                }
            }
        }
    }
}

Will generate a `ClassCastException` when called:

class ImplementsTrait implements LowerTrait {
}
new ImplementsTrait().threeCalls()

raises:

Caught: java.lang.ClassCastException: LowerTrait$Trait$Helper$_threeCalls_closure1 cannot be cast to UpperTrait
java.lang.ClassCastException: LowerTrait$Trait$Helper$_threeCalls_closure1 cannot be cast to UpperTrait
	at LowerTrait$Trait$Helper$_threeCalls_closure1$_closure2.doCall(LowerTrait.groovy:9)
etc..