1321738 - Xrays don't expose some symbol-named props when asking for the list of an object's properties

Status: NEW

(Core :: DOM: Bindings (WebIDL), defect, P3)

Description

[Boris Zbarsky [:bzbarsky]]

Simple testcase: in a chrome scratchpad targeting a non-e10s window, evaluate:

  Object.getOwnPropertySymbols(content.Node).map(String)

and compare it to:

  Object.getOwnPropertySymbols(content.Node.wrappedJSObject).map(String)

Note that the latter includes "Symbol(Symbol.hasInstance)" and the former does not.  At the same time,

  content.Node[Symbol.hasInstance]

returns a function.  The problem is that XrayOwnPropertyKeys didn't get updated when we added some symbol-named stuff to Xrays...

Note that we _do_ seem to get this right for @@iterator:

  Object.getOwnPropertySymbols(content.HTMLCollection.prototype).map(String)

shows it.  Presumably because that's actually in our property arrays?

So it's possible this is limited to @@hasInstance on interface objects and @@unscopables on some prototype objects.  Those are the two things we define by hand with symbol names.  And I guess we don't expose @@unscopables over Xrays at all.