1 files changed, 84 insertions, 0 deletions
diff --git a/toolkit/components/pictureinpicture/tests/browser_removeVideoElement.js b/toolkit/components/pictureinpicture/tests/browser_removeVideoElement.js
new file mode 100644
index 0000000000..d9622dc3f0
--- /dev/null
+++ b/toolkit/components/pictureinpicture/tests/browser_removeVideoElement.js
@@ -0,0 +1,84 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests that if a <video> element is being displayed in a
+ * Picture-in-Picture window, that the window closes if that
+ * original <video> is ever removed from the DOM.
+ */
+add_task(async () => {
+  for (let videoID of ["with-controls", "no-controls"]) {
+    info(`Testing ${videoID} case.`);
+
+    await BrowserTestUtils.withNewTab(
+      {
+        url: TEST_PAGE,
+        gBrowser,
+      },
+      async browser => {
+        let pipWin = await triggerPictureInPicture(browser, videoID);
+        Assert.ok(pipWin, "Got PiP window.");
+
+        // First, let's make sure that removing the _other_ video doesn't cause
+        // the special event to fire, nor the PiP window to close.
+        await SpecialPowers.spawn(browser, [videoID], async videoID => {
+          let doc = content.document;
+          let otherVideo = doc.querySelector(`video:not([id="${videoID}"])`);
+          let eventFired = false;
+
+          let listener = e => {
+            eventFired = true;
+          };
+
+          docShell.chromeEventHandler.addEventListener(
+            "MozStopPictureInPicture",
+            listener,
+            {
+              capture: true,
+            }
+          );
+          otherVideo.remove();
+          Assert.ok(
+            !eventFired,
+            "Should not have seen MozStopPictureInPicture for other video"
+          );
+          docShell.chromeEventHandler.removeEventListener(
+            "MozStopPictureInPicture",
+            listener,
+            {
+              capture: true,
+            }
+          );
+        });
+
+        Assert.ok(!pipWin.closed, "PiP window should still be open.");
+
+        await SpecialPowers.spawn(browser, [videoID], async videoID => {
+          let doc = content.document;
+          let video = doc.querySelector(`#${videoID}`);
+
+          let promise = ContentTaskUtils.waitForEvent(
+            docShell.chromeEventHandler,
+            "MozStopPictureInPicture",
+            { capture: true }
+          );
+          video.remove();
+          await promise;
+        });
+
+        try {
+          await BrowserTestUtils.waitForCondition(
+            () => pipWin.closed,
+            "Player window closed."
+          );
+        } finally {
+          if (!pipWin.closed) {
+            await BrowserTestUtils.closeWindow(pipWin);
+          }
+        }
+      }
+    );
+  }
+});