1 files changed, 80 insertions, 0 deletions
diff --git a/dom/events/test/browser_keyboard_event_init_key_event_enabled_in_contentscript.js b/dom/events/test/browser_keyboard_event_init_key_event_enabled_in_contentscript.js
new file mode 100644
index 0000000000..e8d51edb3e
--- /dev/null
+++ b/dom/events/test/browser_keyboard_event_init_key_event_enabled_in_contentscript.js
@@ -0,0 +1,80 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+async function installAndStartExtension() {
+  function contentScript() {
+    window.addEventListener(
+      "load",
+      () => {
+        document.documentElement.setAttribute(
+          "data-initKeyEvent-in-contentscript",
+          typeof window.KeyboardEvent.prototype.initKeyEvent
+        );
+      },
+      { capture: true, once: true }
+    );
+  }
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [
+        {
+          js: ["content_script.js"],
+          matches: ["<all_urls>"],
+          run_at: "document_start",
+        },
+      ],
+    },
+    files: {
+      "content_script.js": contentScript,
+    },
+  });
+
+  await extension.startup();
+
+  return extension;
+}
+
+add_task(async function () {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["dom.keyboardevent.init_key_event.enabled", false],
+      ["dom.keyboardevent.init_key_event.enabled_in_addons", true],
+    ],
+  });
+
+  const extension = await installAndStartExtension();
+  await BrowserTestUtils.withNewTab(
+    "http://example.com/browser/dom/events/test/file_keyboard_event_init_key_event_enabled_in_contentscript.html",
+    async browser => {
+      info("Waiting for the test result...");
+      await SpecialPowers.spawn(browser, [], () => {
+        Assert.equal(
+          content.document.documentElement.getAttribute(
+            "data-initKeyEvent-before"
+          ),
+          "undefined",
+          "KeyboardEvent.initKeyEvent shouldn't be available in web-content"
+        );
+        Assert.equal(
+          content.document.documentElement.getAttribute(
+            "data-initKeyEvent-in-contentscript"
+          ),
+          "function",
+          "KeyboardEvent.initKeyEvent should be available in contentscript"
+        );
+        Assert.equal(
+          content.document.documentElement.getAttribute(
+            "data-initKeyEvent-after"
+          ),
+          "undefined",
+          "KeyboardEvent.initKeyEvent shouldn't be available in web-content even after contentscript accesses it"
+        );
+      });
+    }
+  );
+
+  await extension.unload();
+});