Proposal: Allow specifying frameId for devtools.inspectedWindow.eval api

[scurker]

Background

We recently ran into a limitation with the devtools.inspectedWindow.eval api where we need to target specific frames in order to send a inspect command within context of the devtools api to inspect a specific element. This works in most cases as we are able to specify a unique url to target the frame:

browser.devtools.inspectedWindow.eval(`inspect(document.querySelector("${selector}"))`, {
  frameURL: targetFrameURL,
  useContentScriptContext: true
})

However, we ran into a limitation where there are identical frames with the same url within context of the page, and have no way to uniquely send commands to distinct frames with identical urls with this api. Normally, we utilize browser.tabs.sendMessage with specifying the frameId of the desired frame, but we need access to the devtools api in order to call inspect.

Proposal

Similar to browser.tabs.sendMessage, browser.devtools.inspectedWindow.eval should support specifying frameId in order to target distinct frames without relying on the frame url:

browser.devtools.inspectedWindow.eval(`...`, {
  frameId: targetFrameId,
  useContentScriptContext: true
})

[bershanskiy]

Also same goes for documentId (which is a stronger way of targeting a context: the same frame hosting the same document).