From:  Jan de Mooij <jdemooij@mozilla.com>
Date:  13 Jan 2019 17:30:01 Hong Kong Time
Newsgroup:  news.mozilla.org/mozilla.dev.tech.js-engine.internals
Subject:  

newGlobal changes

NNTP-Posting-Host:  63.245.210.105

Hi all,

I made some changes to how newGlobal works in the JS shell, to improve our
test coverage:

   1. newGlobal now creates the new global in the caller's compartment.
   Shell tests that require the global to be in a new compartment (for example
   because they use the Debugger API or things like nukeAllCCWs) have been
   updated to use newGlobal({newCompartment: true}).

   2. To ensure we don't lose test coverage for the
   cross-compartment-global case, a --more-compartments flag has been added to
   the shell. This flag makes newGlobal create a new compartment by default,
   as it did before. I added this flag to some of the shell flag combinations
   we use in automation, to make sure jit-tests and jsreftests in the shell
   run in both same-compartment and cross-compartment environments.

   If you don't have a good reason to use the newCompartment or
   sameCompartmentAs options, just use plain newGlobal() so we run your test
   in both configurations.

Note that our chrome globals (windows and sandboxes) are already
same-compartment, so we actually ship both of these configurations in
Firefox.

Cheers,
Jan