With mixin, access to method toString() not consistent

The same bug appear with 1.6-RC-2

I just checked that this also occurs with 1.6-beta-2, so I conclude this is not a change due to GROOVY-3252.

I was hoping to give this issue a try, or at least look into it and learn a bit about mixin feature but I can't understand on my own what is the expected behavior of the self.toString() in the example above and how should its delegation work.

Should the toString() call in the example above always do class Bidule's toString() or class ServiceExt's toString()?

For Roshan,

The expected behaviour of the concatenation of
"Description : " + self
and
"Description :" + self.toString
should be the same result because 'self' is the same instance of the class Bidule.
In one case the call to the method 'toString' is implicit and in the other case, explicit.

No, No, I understand that the JIRA is about inconsistency between explicit and implicit calls to toString().

What I don't understand is whether the call to self.toString() should get delegated to Bidule's toString() or class ServiceExt's toString() in this mixin scenario?

My guess is that in both the cases, it should result in "Description : ServiceExt@545e07b6" output but I was getting a different impression from JIRA description.

So, the inconsistent behavior, when using println self.toString()/self, seems to emanating from the fact that a call like "self.toString()" goes through the call-site array whereas "self" does not.

Because "self.toString()" goes through call-site infrastructure (via MetaClassImpl), it is able to see that the toString() method has been replaced by MixinInstanceMetaMethod(MyInteger.toString()). On the other hand, since "self" does not go through call-site, it doesn't encounter the mixin meta methods, and Integer's version of toString() gets invoked.

I have asked another question on the mailing-list about whether mixin should exclude basic methods like those from Object/GroovyObject. If that happens, at least this particular issue may go away. Otherwise, right now I can't work out how the mixin stuff should handle the above scenario.

Here is a workaround

Add to the following method to SerivceExt:

String toString() {
   Bidule.getMethod('toString').invoke(this.metaClass.owner)}} // Change Bidule to whatever usefull
}