1 files changed, 66 insertions, 0 deletions
diff --git a/accessible/tests/browser/e10s/browser_caching_large_update.js b/accessible/tests/browser/e10s/browser_caching_large_update.js
new file mode 100644
index 0000000000..ccf8a86921
--- /dev/null
+++ b/accessible/tests/browser/e10s/browser_caching_large_update.js
@@ -0,0 +1,66 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Test a large update which adds many thousands of Accessibles with a
+ * lot of content in each.
+ */
+addAccessibleTask(
+  `<main id="main" hidden></main>`,
+  async function (browser, docAcc) {
+    let shown = waitForEvent(EVENT_SHOW, "main");
+    await invokeContentTask(browser, [], () => {
+      // Make a long string.
+      let text = "";
+      for (let i = 0; i < 100; ++i) {
+        text += "a";
+      }
+      // Create lots of nodes which include the long string.
+      const contMain = content.document.getElementById("main");
+      // 15000 children of main.
+      for (let w = 0; w < 15000; ++w) {
+        // Each of those goes 9 deep.
+        let parent = contMain;
+        for (let d = 0; d < 10; ++d) {
+          const div = content.document.createElement("div");
+          div.setAttribute("aria-label", `${w} ${d} ${text}`);
+          parent.append(div);
+          parent = div;
+        }
+      }
+      contMain.hidden = false;
+    });
+    const main = (await shown).accessible;
+    is(main.childCount, 15000, "main has correct number of children");
+
+    // We don't want to output passes for every check, since that would output
+    // hundreds of thousands of lines, which slows the test to a crawl. Instead,
+    // output any failures and keep track of overall success/failure.
+    let treeOk = true;
+    function check(val, msg) {
+      if (!val) {
+        ok(false, msg);
+        treeOk = false;
+      }
+    }
+
+    info("Checking tree");
+    for (let w = 0; w < 15000; ++w) {
+      let acc = main.getChildAt(w);
+      let parent = main;
+      for (let d = 0; d < 10; ++d) {
+        check(acc, `Got child ${w} depth ${d}`);
+        const name = `${w} ${d}`;
+        check(acc.name.startsWith(name + " "), `${name}: correct name`);
+        check(acc.parent == parent, `${name}: correct parent`);
+        parent = acc;
+        acc = acc.firstChild;
+      }
+    }
+    // check() sets treeOk to false for any failure.
+    ok(treeOk, "Tree is correct");
+  }
+);