1 files changed, 141 insertions, 0 deletions
diff --git a/testing/mochitest/BrowserTestUtils/ContentTask.sys.mjs b/testing/mochitest/BrowserTestUtils/ContentTask.sys.mjs
new file mode 100644
index 0000000000..6c3df200c7
--- /dev/null
+++ b/testing/mochitest/BrowserTestUtils/ContentTask.sys.mjs
@@ -0,0 +1,141 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
+/* 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/. */
+
+const FRAME_SCRIPT = "resource://testing-common/content-task.js";
+
+/**
+ * Keeps track of whether the frame script was already loaded.
+ */
+var gFrameScriptLoaded = false;
+
+/**
+ * Mapping from message id to associated promise.
+ */
+var gPromises = new Map();
+
+/**
+ * Incrementing integer to generate unique message id.
+ */
+var gMessageID = 1;
+
+/**
+ * This object provides the public module functions.
+ */
+export var ContentTask = {
+  /**
+   * _testScope saves the current testScope from
+   * browser-test.js. This is used to implement SimpleTest functions
+   * like ok() and is() in the content process. The scope is only
+   * valid for tasks spawned in the current test, so we keep track of
+   * the ID of the first task spawned in this test (_scopeValidId).
+   */
+  _testScope: null,
+  _scopeValidId: 0,
+
+  /**
+   * Creates and starts a new task in a browser's content.
+   *
+   * @param browser A xul:browser
+   * @param arg A single serializable argument that will be passed to the
+   *             task when executed on the content process.
+   * @param task
+   *        - A generator or function which will be serialized and sent to
+   *          the remote browser to be executed. Unlike Task.spawn, this
+   *          argument may not be an iterator as it will be serialized and
+   *          sent to the remote browser.
+   * @return A promise object where you can register completion callbacks to be
+   *         called when the task terminates.
+   * @resolves With the final returned value of the task if it executes
+   *           successfully.
+   * @rejects An error message if execution fails.
+   */
+  spawn: function ContentTask_spawn(browser, arg, task) {
+    // Load the frame script if needed.
+    if (!gFrameScriptLoaded) {
+      Services.mm.loadFrameScript(FRAME_SCRIPT, true);
+      gFrameScriptLoaded = true;
+    }
+
+    let deferred = {};
+    deferred.promise = new Promise((resolve, reject) => {
+      deferred.resolve = resolve;
+      deferred.reject = reject;
+    });
+
+    let id = gMessageID++;
+    gPromises.set(id, deferred);
+
+    browser.messageManager.sendAsyncMessage("content-task:spawn", {
+      id,
+      runnable: task.toString(),
+      arg,
+    });
+
+    return deferred.promise;
+  },
+
+  setTestScope(scope) {
+    this._testScope = scope;
+    this._scopeValidId = gMessageID;
+  },
+};
+
+var ContentMessageListener = {
+  receiveMessage(aMessage) {
+    let id = aMessage.data.id;
+
+    if (id < ContentTask._scopeValidId) {
+      throw new Error("test result returned after test finished");
+    }
+
+    if (aMessage.name == "content-task:complete") {
+      let deferred = gPromises.get(id);
+      gPromises.delete(id);
+
+      if (aMessage.data.error) {
+        deferred.reject(aMessage.data.error);
+      } else {
+        deferred.resolve(aMessage.data.result);
+      }
+    } else if (aMessage.name == "content-task:test-result") {
+      let data = aMessage.data;
+      ContentTask._testScope.record(
+        data.condition,
+        data.name,
+        null,
+        data.stack
+      );
+    } else if (aMessage.name == "content-task:test-info") {
+      ContentTask._testScope.info(aMessage.data.name);
+    } else if (aMessage.name == "content-task:test-todo") {
+      ContentTask._testScope.todo(aMessage.data.expr, aMessage.data.name);
+    } else if (aMessage.name == "content-task:test-todo_is") {
+      ContentTask._testScope.todo_is(
+        aMessage.data.a,
+        aMessage.data.b,
+        aMessage.data.name
+      );
+    }
+  },
+};
+
+Services.mm.addMessageListener("content-task:complete", ContentMessageListener);
+Services.mm.addMessageListener(
+  "content-task:test-result",
+  ContentMessageListener
+);
+Services.mm.addMessageListener(
+  "content-task:test-info",
+  ContentMessageListener
+);
+Services.mm.addMessageListener(
+  "content-task:test-todo",
+  ContentMessageListener
+);
+Services.mm.addMessageListener(
+  "content-task:test-todo_is",
+  ContentMessageListener
+);