Right now, elements in third-party iframes which are being inspected in the devtools (`$0`) cannot be accessed/modified unless the devtools context is that third-party iframe. Unfortunately, `devtools.inspectedWindow.eval` does not support the `frameURL` option, making it impossible to do the same in an add-on. This (for instance) makes it impossible for the [Testcase Reducer](https://addons.mozilla.org/en-US/firefox/addon/testcase-reducer/) addon to reduce a testcase for an element in a third-party iframe, as it cannot pass a reference to the frame or even mark the element in some way for the iframe context to know it is the element that is`$0`.
Bug 1581721 Comment 0 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Right now, elements in third-party iframes which are being inspected in the devtools (`$0`) cannot be accessed/modified unless the devtools context is that third-party iframe. Unfortunately, `devtools.inspectedWindow.eval` does not support the `frameURL` option [1], making it impossible to do the same in an add-on. This (for instance) makes it impossible for the [Testcase Reducer](https://addons.mozilla.org/en-US/firefox/addon/testcase-reducer/) addon to reduce a testcase for an element in a third-party iframe, as it cannot pass a reference to the frame or even mark the element in some way for the iframe context to know it is the element that is`$0`. [1] https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/devtools.inspectedWindow/eval#Parameters