[GROOVY-6600] Compilation error when creating an anonymous subclass of a class implementing propertyMissing setter

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.1.9, 2.2.2, 2.4.0-rc-1
• Component/s: class generator, Compiler
• Environment: Ubuntu Linux; Oracle JDK 1.7.0_45 64-bit; Groovy 2.2.2; Groovy 2.1.9
• Assignee: Unassigned
• Reporter: Christopher Koenig
• Created: 26/Feb/14 14:26
• Updated: 13/Apr/15 08:57

Description

Creating an anonymous subclass of class that implements a propertyMissing setter with return type of "def" results in a compilation error:

// This code does not work
class FooA {    
    Map m = [:]    
    def propertyMissing(String name, def value) { m[name] = value }
}

// This statement produces a compilation error
def anonSubclass = new FooA(){}

The compilation error is as follows:

1 compilation error:

The return type of void propertyMissing(java.lang.String, java.lang.Object) in ConsoleScript7$1 is incompatible with java.lang.Object propertyMissing(java.lang.String, java.lang.Object) in FooA
. At [-1:-1]  at line: -1, column: -1

Declaring and instantiating a named subclass of FooA produces no errors.

// This code works.
class FooB extends FooA {}
def namedSubclass = new FooB()

As a workaround, the propertyMissing setter can be declared with a "void" return type.

// This code works
class FooC {    
    Map m = [:]
    void propertyMissing(String name, def value) { m[name] = value }
}

def anonSubclass2 = new FooC(){}