Subj : Re: Assigning to a nonexistent property
To   : Braden McDaniel
From : Brendan Eich
Date : Thu Dec 09 2004 11:09 am

Braden McDaniel wrote:
> I have defined a type whose JSClass::setProperty is simply
> JSPropertyStub. I would have expected an attempt to assign to a property
> on instances of this type (e.g., "instance.prop = foo") would result in
> an error message.

Why?  Stub means no-op, usually.  And ECMA by default does not seal 
objects, and stubs are for "most common" default cases.

> Instead, I get no error message and the code seems to
> be a no-op. Is there something I should be doing to make this an error
> condition? (Aside from adding a setter that simply reports an error.)

Do you want to seal the object against all future sets, adds, and 
deletes?  If so, consider JS_SealObject (beware passing true for the 
|deep| param! ;-).

/be

.