1 files changed, 65 insertions, 0 deletions
diff --git a/docshell/test/browser/browser_browsing_context_discarded.js b/docshell/test/browser/browser_browsing_context_discarded.js
new file mode 100644
index 0000000000..a300737d4f
--- /dev/null
+++ b/docshell/test/browser/browser_browsing_context_discarded.js
@@ -0,0 +1,65 @@
+"use strict";
+
+const TOPIC = "browsing-context-discarded";
+
+async function observeDiscarded(browsingContexts, callback) {
+  let discarded = [];
+
+  let promise = BrowserUtils.promiseObserved(TOPIC, subject => {
+    ok(BrowsingContext.isInstance(subject), "subject to be a BrowsingContext");
+    discarded.push(subject);
+
+    return browsingContexts.every(item => discarded.includes(item));
+  });
+  await callback();
+  await promise;
+
+  return discarded;
+}
+
+add_task(async function toplevelForNewWindow() {
+  let win = await BrowserTestUtils.openNewBrowserWindow();
+  let browsingContext = win.gBrowser.selectedBrowser.browsingContext;
+
+  await observeDiscarded([win.browsingContext, browsingContext], async () => {
+    await BrowserTestUtils.closeWindow(win);
+  });
+});
+
+add_task(async function toplevelForNewTab() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser);
+  let browsingContext = tab.linkedBrowser.browsingContext;
+
+  let discarded = await observeDiscarded([browsingContext], () => {
+    BrowserTestUtils.removeTab(tab);
+  });
+
+  ok(
+    !discarded.includes(window.browsingContext),
+    "no notification for the current window's chrome browsing context"
+  );
+});
+
+add_task(async function subframe() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser);
+  let browsingContext = await SpecialPowers.spawn(tab.linkedBrowser, [], () => {
+    let iframe = content.document.createElement("iframe");
+    content.document.body.appendChild(iframe);
+    iframe.contentWindow.location = "https://example.com/";
+    return iframe.browsingContext;
+  });
+
+  let discarded = await observeDiscarded([browsingContext], async () => {
+    await SpecialPowers.spawn(tab.linkedBrowser, [], () => {
+      let iframe = content.document.querySelector("iframe");
+      iframe.remove();
+    });
+  });
+
+  ok(
+    !discarded.includes(tab.browsingContext),
+    "no notification for toplevel browsing context"
+  );
+
+  BrowserTestUtils.removeTab(tab);
+});