1 files changed, 90 insertions, 0 deletions
diff --git a/addon-sdk/source/test/addons/content-script-messages-latency/main.js b/addon-sdk/source/test/addons/content-script-messages-latency/main.js
new file mode 100644
index 000000000..39bd7b64b
--- /dev/null
+++ b/addon-sdk/source/test/addons/content-script-messages-latency/main.js
@@ -0,0 +1,90 @@
+/* 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";
+
+const { PageMod } = require("sdk/page-mod");
+const tabs = require("sdk/tabs");
+const { startServerAsync } = require("./httpd");
+const { setTimeout } = require("sdk/timers");
+
+const serverPort = 8099;
+
+exports.testContentScriptLatencyRegression = function*(assert) {
+  let server = startServerAsync(serverPort);
+  server.registerPathHandler("/", function handle(request, response) {
+    response.write(`<html>
+      <head>
+        <link rel="stylesheet" href="/slow.css">
+      </head>
+      <body>
+        slow loading page...
+      </body>
+    </html>`);
+  });
+
+  server.registerPathHandler("/slow.css", function handle(request, response) {
+    response.processAsync();
+    response.setHeader('Content-Type', 'text/css', false);
+    setTimeout(_ => {
+      response.write("body { background: red; }");
+      response.finish();
+    }, 2000);
+  });
+
+
+  let pageMod;
+
+  let worker = yield new Promise((resolve) => {
+    pageMod = PageMod({
+      include: "http://localhost:8099/",
+      attachTo: "top",
+      contentScriptWhen: "start",
+      contentScript: "new " + function ContentScriptScope() {
+        self.port.on("a-port-message", function () {
+          self.port.emit("document-ready-state", document.readyState);
+        });
+      },
+      onAttach: function(w) {
+        resolve(w);
+      }
+    });
+
+    tabs.open({
+      url: "http://localhost:8099/",
+      inBackground: true
+    });
+  });
+
+  worker.port.emit("a-port-message");
+
+  let waitForPortMessage = new Promise((resolve) => {
+    worker.port.once("document-ready-state", (msg) => {
+      resolve(msg);
+    });
+  });
+
+  let documentReadyState = yield waitForPortMessage;
+
+  assert.notEqual(
+    "complete", documentReadyState,
+    "content script received the port message when the page was still loading"
+  );
+
+  assert.notEqual(
+    "uninitialized", documentReadyState,
+    "content script should be frozen if document.readyState is still uninitialized"
+  );
+
+  assert.ok(
+    ["loading", "interactive"].includes(documentReadyState),
+    "content script message received with document.readyState was interactive or loading"
+  );
+
+  // Cleanup.
+  pageMod.destroy();
+  yield new Promise((resolve) => worker.tab.close(resolve));
+  yield new Promise((resolve) => server.stop(resolve));
+};
+
+require("sdk/test/runner").runTestsFromModule(module);