Incumbent Globals in Promises

[jgraham]

Description

Gecko correctly implements Incumbent Settings objects for promises per the current HTML spec, however this is not implemented in WebKit or Chromium. This can cause e.g. messages sent from postMessage to appear to have different sources across browsers.

Note: an acceptable outcome would be a spec change that allows everyone to align on the same behaviour.

Specification

https://html.spec.whatwg.org/#hostenqueuepromisejob

web-feature

No response

Test Links

https://wpt.fyi/results/html/webappapis/scripting/processing-model-2/integration-with-the-javascript-job-queue/promise-job-incumbent.html?label=experimental&label=master&aligned

Additional Signals

No response