testing/mochitest/BrowserTestUtils/ContentTask.jsm
author Nika Layzell <nika@thelayzells.com>
Thu, 06 Aug 2020 14:04:13 +0000
changeset 544125 ee09cb88af177571304759bc05c760e3d82fd1ed
parent 481418 51c89fcec893529391427e14709a2d1bc9c2a962
permissions -rw-r--r--
Bug 1656854 - Part 2: Add a BrowsingContextGroup keepalive to BrowserParent shutdown, r=farre In bug 1652085, I added BrowsingContextGroup keepalives while waiting for replies to the discard message, however that message isn't actually sent to the current owner process. Instead, the BrowsingContext is discarded by the PBrowser being destroyed. This should help ensure we also keep the group alive during normal BrowserParent destruction. Differential Revision: https://phabricator.services.mozilla.com/D85897

/* -*- 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/. */

"use strict";

var EXPORTED_SYMBOLS = ["ContentTask"];

const { Promise } = ChromeUtils.import("resource://gre/modules/Promise.jsm");
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");

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.
 */
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
);