Playwright integration or runtime overrides solution

[kristojorg]

Hi all, I am wondering if anyone has a working example of using MSW with Playwright and enabling runtime handler overrides? I have previously had this working using playwright-msw, but that library appears to be unmaintained and has stopped working for me. I have also taken a look at various examples such at the remix example, but none of the example I could find actually use runtime overrides.

I have seen @kettanaito mention that runtime overrides can be enabled by exposing msw on the window object of the app, then using page.evaluate(() => { msw.worker.use(...) }) in a test. However, the service worker is not registered until the page runs, at which point my application is also already making network requests I would like to mock.

The playwright-msw package avoided this issue by transforming msw handlers into Playwright's Page.route() format. Playwright is then using the Chrome Devtools protocol to intercept requests rather than setting up a service worker, which means the handlers can be registered before the page is actually requested or loaded.

I'm wondering if anyone has found a working solution to this? If not, shall we open a discussion about how MSW could integrate directly with playwright?