[GROOVY-5357] The accessor pair can't be provided from different sources

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.3, 4.0.0
• Component/s: groovy-runtime
• Assignee: Jochen Theodorou
• Reporter: OC
• Created: 11/Mar/12 15:08
• Updated: 22/Dec/23 11:38
• Resolved: 22/Aug/23 10:39

Description

When one of the accessor pair is added through a mixin or metaclass, Groovy behaves as if the other one did not exist.

Explanation kindly provided by Paul: "MetaClassImpl finds a MetaBeanProperty containing just the getter. When only a getter is found there is an incorrect assumption that a setter doesn't exist in the underlying class."

class Foo {
  void setVal(v) { println "setVal: $v" }
}
@Category(Foo) class Getter {
 def getVal() { println "getVal" }
}
class Test {
  static def main(av) {
    Foo.mixin Getter
    def f = new Foo()
    f.setVal('foo')
    f.val = null // => groovy.lang.ReadOnlyPropertyException: Cannot set readonly property: val for class: Foo
  }
}

or

class Foo {
  void setVal(v) { println "setVal: $v" }
}
class Test {
  static def main(av) {
    Foo.metaClass.getVal={-> println "getval" }
    def f = new Foo()
    f.setVal('foo')
    f.val = null // => groovy.lang.ReadOnlyPropertyException: Cannot set readonly property: val for class: Foo
  }
}

or

class Foo {
  def getVal() { println "getVal" }
}
class Test {
  static def main(av) {
    Foo.metaClass.setVal={v-> }
    def f = new Foo()
    f.getVal()
    f.val
  }
}

etc.