[Feature] extension message passing in non-persistent context

Context:

• Playwright Version: 1.5.1, 1.6.1
• Operating System: Mac (local) Linux (via CI)
• Node.js version: 14.x
• Browser: Chromium
• Extra: non-headless

Code Snippet

chrome.tabs.sendMessage fails on fails on chromium.launch, but not on chromium.launchPersistentContext

// @filename content.js
chrome.runtime.sendMessage(undefined, message)


// @filename background.js
chrome.runtime.onMessage.addListener((message, sender) => {
  if (typeof sender?.tab?.id !== 'number') return
  chrome.tabs.sendMessage(sender.tab.id, message, { frameId: 0 }) // 💥
})

💥 "Could not establish connection. Receiving end does not exist."

Describe the bug

I’ve created a repo to further describe and isolate this bug.

the only dependencies are node and playwright itself.

the log on GitHub Actions help with visualising the mismatch between the persistent context and the default ones.

I wasn’t able to reproduce it on a Chromium Incognito window locally. 🤔

[pavelfeldman]

chrome.tabs.sendMessage fails on fails on chromium.launch, but not on chromium.launchPersistentContext

This is by design. At this point, support for extensions in Playwright is in the best effort mode. We focus on the cross-browser web testing instead. In order to test extensions, you should run Playwright in a mode that is as close to the regular execution as possible, in this case it means running it as chromium.launchPersistentContext and specifying the user data dir.

[aslushnikov]

I wasn’t able to reproduce it on a Chromium Incognito window locally. 🤔

@leonardodino by default, extensions don’t run in incognito windows in Chromium (so they don’t run for you in the Playwright default context). I tried with your extension, and it doesn’t run in incognito as well. Could it be that you explicitly enable it in extension settings?