test that youtube embeds work (#24726)

* test that YouTube embeds work

* tidying

tests/browser/browser.js

@@ -474,3 +474,34 @@ describe.skip('next/link client-side navigation', () => {
     await page.setViewport(initialViewport)
   })
 })
+
+describe('iframe pages', () => {
+  it('can open YouTube embed iframes', async () => {
+    // Going to create a fresh page instance, so we can intercept the requests.
+    const newPage = await browser.newPage()
+
+    await newPage.setRequestInterception(true)
+    const interceptedURLs = []
+    newPage.on('request', (request) => {
+      interceptedURLs.push(request.url())
+      request.continue()
+    })
+    const failedURLs = []
+    newPage.on('requestfailed', (request) => {
+      failedURLs.push(request.url())
+      request.continue()
+    })
+
+    // Hardcoded path to a page where we know we have a YouTube embed
+    const res = await newPage.goto('http://localhost:4001/en/codespaces')
+
+    expect(res.ok()).toBeTruthy()
+    expect(failedURLs.length, `Following URLs ${failedURLs.join(', ')} failed`).toBeFalsy()
+
+    const iframeSrc = await newPage.$eval('iframe', (el) => el.src)
+    expect(iframeSrc.startsWith('https://www.youtube-nocookie.com/embed')).toBeTruthy()
+    expect(
+      interceptedURLs.filter((url) => url.startsWith('https://www.youtube-nocookie.com/')).length
+    ).toBeTruthy()
+  })
+})