1 files changed, 98 insertions, 0 deletions
diff --git a/remote/shared/messagehandler/test/browser/browser_bfcache.js b/remote/shared/messagehandler/test/browser/browser_bfcache.js
new file mode 100644
index 0000000000..f829d8b58d
--- /dev/null
+++ b/remote/shared/messagehandler/test/browser/browser_bfcache.js
@@ -0,0 +1,98 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { RootMessageHandler } = ChromeUtils.importESModule(
+  "chrome://remote/content/shared/messagehandler/RootMessageHandler.sys.mjs"
+);
+
+const TEST_PREF = "remote.messagehandler.test.pref";
+
+// Check that pages in bfcache no longer have message handlers attached to them,
+// and that they will not emit unexpected events.
+add_task(async function test_bfcache_broadcast() {
+  const tab = await addTab("https://example.com/document-builder.sjs?html=tab");
+  const rootMessageHandler = createRootMessageHandler("session-id-bfcache");
+
+  try {
+    const browsingContext = tab.linkedBrowser.browsingContext;
+    const contextDescriptor = {
+      type: ContextDescriptorType.TopBrowsingContext,
+      id: browsingContext.browserId,
+    };
+
+    // Whenever a "preference-changed" event from the eventonprefchange module
+    // will be received on the root MessageHandler, increment a counter.
+    let preferenceChangeEventCount = 0;
+    const onEvent = (evtName, wrappedEvt) => {
+      if (wrappedEvt.name === "preference-changed") {
+        preferenceChangeEventCount++;
+      }
+    };
+    rootMessageHandler.on("message-handler-event", onEvent);
+
+    // Initialize the preference, no eventonprefchange module should be created
+    // yet so preferenceChangeEventCount is not expected to be updated.
+    Services.prefs.setIntPref(TEST_PREF, 0);
+    await TestUtils.waitForCondition(() => preferenceChangeEventCount >= 0);
+    is(preferenceChangeEventCount, 0);
+
+    // Broadcast a "ping" command to force the creation of the eventonprefchange
+    // module
+    let values = await sendPingCommand(rootMessageHandler, contextDescriptor);
+    is(values.length, 1, "Broadcast returned a single value");
+
+    Services.prefs.setIntPref(TEST_PREF, 1);
+    await TestUtils.waitForCondition(() => preferenceChangeEventCount >= 1);
+    is(preferenceChangeEventCount, 1);
+
+    info("Navigate to another page");
+    await loadURL(
+      tab.linkedBrowser,
+      "https://example.com/document-builder.sjs?html=othertab"
+    );
+
+    values = await sendPingCommand(rootMessageHandler, contextDescriptor);
+    is(values.length, 1, "Broadcast returned a single value after navigation");
+
+    info("Update the preference and check we only receive 1 event");
+    Services.prefs.setIntPref(TEST_PREF, 2);
+    await TestUtils.waitForCondition(() => preferenceChangeEventCount >= 2);
+    is(preferenceChangeEventCount, 2);
+
+    info("Navigate to another origin");
+    await loadURL(
+      tab.linkedBrowser,
+      "https://example.org/document-builder.sjs?html=otherorigin"
+    );
+
+    values = await sendPingCommand(rootMessageHandler, contextDescriptor);
+    is(
+      values.length,
+      1,
+      "Broadcast returned a single value after cross origin navigation"
+    );
+
+    info("Update the preference and check again that we only receive 1 event");
+    Services.prefs.setIntPref(TEST_PREF, 3);
+    await TestUtils.waitForCondition(() => preferenceChangeEventCount >= 3);
+    is(preferenceChangeEventCount, 3);
+  } finally {
+    rootMessageHandler.destroy();
+    gBrowser.removeTab(tab);
+    Services.prefs.clearUserPref(TEST_PREF);
+  }
+});
+
+function sendPingCommand(rootMessageHandler, contextDescriptor) {
+  return rootMessageHandler.handleCommand({
+    moduleName: "eventonprefchange",
+    commandName: "ping",
+    params: {},
+    destination: {
+      contextDescriptor,
+      type: WindowGlobalMessageHandler.type,
+    },
+  });
+}