522764 - COWs need tests

Status: RESOLVED FIXED

(Core :: XPConnect, defect)

Description

[Atul Varma [:atul]]

COWs need a test suite to ensure that they expose properties as per our specification (see bug 518991).

Comment 1

[Atul Varma [:atul]]

I've got a 17-test suite in a patch against trunk here:

  http://hg.mozilla.org/users/avarma_mozilla.com/cow-patches/file/df226305b064/cow_tests_3.patch

However, there's a notable TODO in it. At the moment, because it's not yet possible to create a COW from script, I've added a method called GetCOWForObject() to nsIDOMWindowUtils.  This method should only be callable from mochitest pages with UniversalXPConnect privileges, but right now the patch disables this functionality because it prevents a content-space Components.utils.Sandbox() from being able to make COWs.

There's different ways we can get around this.  One, which is mentioned in the patch, may be to make GetCOWForObject() a factory method that checks for UniversalXPConnect and then returns a function for creating COWs.  Another option is to figure out exactly what's causing the privilege-checking code to fail when uncommented and fixing it, if that's possible (if it is, I don't know how to accomplish it).  If we want to do the former, I can add the functionality to the patch.

Comment 2

[Atul Varma [:atul]]

Fixed this problem after talking to mrbkap and finding out that we can just enable UniversalXPConnect in the getCOW() function that's injected into the sandbox; UniversalXPConnect doesn't leak b/c it goes away once the stack frame it was enabled in disappears.

Latest patch is now here:

  http://hg.mozilla.org/users/avarma_mozilla.com/cow-patches/file/9e232a2d8276/cow_tests_3.patch

Comment 3

[Atul Varma [:atul]]

nsDOMWindowUtils::getCOWForObject() now takes a scope parameter, as per mrbkap's suggestion:

  http://hg.mozilla.org/users/avarma_mozilla.com/cow-patches/file/309eb898fadc/cow_tests_3.patch

Comment 4

[Atul Varma [:atul]]

Attachment: Patch for this bug.

This patch is taken from:

http://hg.mozilla.org/users/avarma_mozilla.com/cow-patches/file/ffc79bd95c2b/cow_tests_3.patch

Comment 5

[Blake Kaplan (:mrbkap) (inactive)]

Comment on attachment 406791 [details] [diff] [review]
Patch for this bug.

Looks good.

Comment 6

[Blake Kaplan (:mrbkap) (inactive)]

http://hg.mozilla.org/mozilla-central/rev/8976e1704153 with a new iid for nsIDOMWindowUtils.

Comment 7

[Atul Varma [:atul]]

Blake, shouldn't this get pushed to the 1.9.2 branch to ensure that COWs work on it, since COW support is in 1.9.2?

Comment 8

[Blake Kaplan (:mrbkap) (inactive)]

jst, in order to get this on 1.9.2, do we need to make an nsIDOMWindowUtils_1_9_2?

Comment 9

[Blake Kaplan (:mrbkap) (inactive)]

Comment on attachment 406791 [details] [diff] [review]
Patch for this bug.

It would be good to get tests for COWs on the 1.9.2 branch. I talked with jst, who said not to worry about the interface change.

Comment 10

[Johnny Stenback (:jst)]

Comment on attachment 406791 [details] [diff] [review]
Patch for this bug.

a=jst with a new iid on 1.9.2 as well.

Comment 11

[Blake Kaplan (:mrbkap) (inactive)]

http://hg.mozilla.org/releases/mozilla-1.9.2/rev/6c6104362063