Messages from the dev tools have no reference about the tab

[fregante]

Since the editor is just a page running in a custom app (the dev tools), they don't have a "tab" and don't report which tab they're operating on. This is the sender information for a message coming from the dev tools (to the background page):

{
  id: "mpjjildhmpddojocokjkgmlkkkfjnepo",
  origin: "chrome-extension://mpjjildhmpddojocokjkgmlkkkfjnepo",
  url: "chrome-extension://mpjjildhmpddojocokjkgmlkkkfjnepo/devtoolsPanel.html"
}

This means that any context known to lack a sender.tab information will need to also provide a tabId. In this case, the browser.runtime.onMessage handler in background would be called with these arguments:

[
  { // Message, custom
    type: 'REPORT_ERROR',
    args: [],
    tab: 123
  },
  { // Sender, browser-provided
    id: "mpjjildhmpddojocokjkgmlkkkfjnepo",
    origin: "chrome-extension://mpjjildhmpddojocokjkgmlkkkfjnepo",
    url: "chrome-extension://mpjjildhmpddojocokjkgmlkkkfjnepo/devtoolsPanel.html"
  }
]

and then it would build the usual MessengerMeta object like this one before calling the handler:

{
	trace: [{
		tabId: 123,
		context: "devtools"
	}]
}

Related

• Preserve sender trace information while forwarding #32