1 files changed, 43 insertions, 0 deletions
diff --git a/accessible/tests/browser/tree/browser_lazy_tabs.js b/accessible/tests/browser/tree/browser_lazy_tabs.js
new file mode 100644
index 0000000000..f7aa9bdeb2
--- /dev/null
+++ b/accessible/tests/browser/tree/browser_lazy_tabs.js
@@ -0,0 +1,43 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that lazy background tabs aren't unintentionally loaded when building
+// the a11y tree (bug 1700708).
+addAccessibleTask(``, async function (browser, accDoc) {
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.sessionstore.restore_on_demand", true]],
+  });
+
+  info("Opening a new window");
+  let win = await BrowserTestUtils.openNewBrowserWindow();
+  // Window is opened with a blank tab.
+  info("Loading second tab");
+  await BrowserTestUtils.openNewForegroundTab({
+    gBrowser: win.gBrowser,
+    url: "data:text/html,2",
+  });
+  info("Loading third tab");
+  await BrowserTestUtils.openNewForegroundTab({
+    gBrowser: win.gBrowser,
+    url: "data:text/html,3",
+  });
+  info("Closing the window");
+  await BrowserTestUtils.closeWindow(win);
+
+  is(SessionStore.getClosedWindowCount(), 1, "Should have a window to restore");
+  info("Restoring the window");
+  win = SessionStore.undoCloseWindow(0);
+  await BrowserTestUtils.waitForEvent(win, "SSWindowStateReady");
+  await BrowserTestUtils.waitForEvent(
+    win.gBrowser.tabContainer,
+    "SSTabRestored"
+  );
+  is(win.gBrowser.tabs.length, 3, "3 tabs restored");
+  ok(win.gBrowser.tabs[2].selected, "Third tab selected");
+  ok(getAccessible(win.gBrowser.tabs[1]), "Second tab has accessible");
+  ok(!win.gBrowser.browsers[1].isConnected, "Second tab is lazy");
+  info("Closing the restored window");
+  await BrowserTestUtils.closeWindow(win);
+});