[GROOVY-8820] Closure inside trait cannot use Closure's delegate variables

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.15, 3.0.0-alpha-3, 2.5.2
• Fix Version/s: 4.0.0-alpha-1, 3.0.6
• Environment: Groovy Version: 3.0.0-alpha-3 JVM: 1.8.0_171 Vendor: Oracle Corporation OS: Mac OS X
• Assignee: Eric Milles
• Reporter: Renato Athaydes
• Created: 01/Oct/18 18:19
• Updated: 11/Nov/20 02:00
• Resolved: 10/Aug/20 13:54

Description

The following code throws an error at runtime:

 

trait T {
    def doIt() {
        return {
            n = 1
        }
    }
}

class Delegate {
    int n
}
    
class Tish implements T {
    def go() {
        def closure = doIt()
        def d = new Delegate()
        closure.delegate = d
        closure()
        assert d.n == 1
        println "All good!"
    }
}

new Tish().go()

 

This is the error I see on Groovy 3.0.0-alpha-3 (same as previous versions):

 

groovy.lang.MissingPropertyException: No such property: n for class: Tish

 

This is expected to work because, outside of traits, it does: this runs successfully:

 

class T {
    def doIt() {
        return {
            n = 1
        }
    }
}

class Delegate {
    int n
}
    
class Tisha extends T {
    def go() {
        def closure = doIt()
        def d = new Delegate()
        closure.delegate = d
        closure()
        assert d.n == 1
        println "All good!"
    }
}

new Tisha().go()