Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3242 insertions, 0 deletions

diff --git a/remote/marionette/driver.sys.mjs b/remote/marionette/driver.sys.mjs
new file mode 100644
index 0000000000..1306d18569
--- /dev/null
+++ b/remote/marionette/driver.sys.mjs
@@ -0,0 +1,3242 @@
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+import {
+  element,
+  WebReference,
+} from "chrome://remote/content/marionette/element.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Addon: "chrome://remote/content/marionette/addon.sys.mjs",
+  AppInfo: "chrome://remote/content/shared/AppInfo.sys.mjs",
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  atom: "chrome://remote/content/marionette/atom.sys.mjs",
+  browser: "chrome://remote/content/marionette/browser.sys.mjs",
+  capture: "chrome://remote/content/shared/Capture.sys.mjs",
+  Context: "chrome://remote/content/marionette/browser.sys.mjs",
+  cookie: "chrome://remote/content/marionette/cookie.sys.mjs",
+  DebounceCallback: "chrome://remote/content/marionette/sync.sys.mjs",
+  disableEventsActor:
+    "chrome://remote/content/marionette/actors/MarionetteEventsParent.sys.mjs",
+  enableEventsActor:
+    "chrome://remote/content/marionette/actors/MarionetteEventsParent.sys.mjs",
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  EventPromise: "chrome://remote/content/shared/Sync.sys.mjs",
+  getMarionetteCommandsActorProxy:
+    "chrome://remote/content/marionette/actors/MarionetteCommandsParent.sys.mjs",
+  IdlePromise: "chrome://remote/content/marionette/sync.sys.mjs",
+  l10n: "chrome://remote/content/marionette/l10n.sys.mjs",
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+  Marionette: "chrome://remote/content/components/Marionette.sys.mjs",
+  MarionettePrefs: "chrome://remote/content/marionette/prefs.sys.mjs",
+  modal: "chrome://remote/content/marionette/modal.sys.mjs",
+  navigate: "chrome://remote/content/marionette/navigate.sys.mjs",
+  permissions: "chrome://remote/content/marionette/permissions.sys.mjs",
+  pprint: "chrome://remote/content/shared/Format.sys.mjs",
+  print: "chrome://remote/content/shared/PDF.sys.mjs",
+  reftest: "chrome://remote/content/marionette/reftest.sys.mjs",
+  registerCommandsActor:
+    "chrome://remote/content/marionette/actors/MarionetteCommandsParent.sys.mjs",
+  RemoteAgent: "chrome://remote/content/components/RemoteAgent.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+  TimedPromise: "chrome://remote/content/marionette/sync.sys.mjs",
+  Timeouts: "chrome://remote/content/shared/webdriver/Capabilities.sys.mjs",
+  UnhandledPromptBehavior:
+    "chrome://remote/content/shared/webdriver/Capabilities.sys.mjs",
+  unregisterCommandsActor:
+    "chrome://remote/content/marionette/actors/MarionetteCommandsParent.sys.mjs",
+  waitForInitialNavigationCompleted:
+    "chrome://remote/content/shared/Navigate.sys.mjs",
+  waitForObserverTopic: "chrome://remote/content/marionette/sync.sys.mjs",
+  WebDriverSession: "chrome://remote/content/shared/webdriver/Session.sys.mjs",
+  windowManager: "chrome://remote/content/shared/WindowManager.sys.mjs",
+  WindowState: "chrome://remote/content/marionette/browser.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "logger", () =>
+  lazy.Log.get(lazy.Log.TYPES.MARIONETTE)
+);
+
+const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
+
+const SUPPORTED_STRATEGIES = new Set([
+  element.Strategy.ClassName,
+  element.Strategy.Selector,
+  element.Strategy.ID,
+  element.Strategy.Name,
+  element.Strategy.LinkText,
+  element.Strategy.PartialLinkText,
+  element.Strategy.TagName,
+  element.Strategy.XPath,
+]);
+
+// Timeout used to abort fullscreen, maximize, and minimize
+// commands if no window manager is present.
+const TIMEOUT_NO_WINDOW_MANAGER = 5000;
+
+// Observer topic to wait for until the browser window is ready.
+const TOPIC_BROWSER_READY = "browser-delayed-startup-finished";
+
+/**
+ * The Marionette WebDriver services provides a standard conforming
+ * implementation of the W3C WebDriver specification.
+ *
+ * @see {@link https://w3c.github.io/webdriver/webdriver-spec.html}
+ * @namespace driver
+ */
+
+/**
+ * Implements (parts of) the W3C WebDriver protocol.  GeckoDriver lives
+ * in chrome space and mediates calls to the current browsing context's actor.
+ *
+ * Throughout this prototype, functions with the argument <var>cmd</var>'s
+ * documentation refers to the contents of the <code>cmd.parameter</code>
+ * object.
+ *
+ * @class GeckoDriver
+ *
+ * @param {MarionetteServer} server
+ *     The instance of Marionette server.
+ */
+export function GeckoDriver(server) {
+  this._server = server;
+
+  // WebDriver Session
+  this._currentSession = null;
+
+  this.browsers = {};
+
+  // points to current browser
+  this.curBrowser = null;
+  // top-most chrome window
+  this.mainFrame = null;
+
+  // Use content context by default
+  this.context = lazy.Context.Content;
+
+  // used for modal dialogs or tab modal alerts
+  this.dialog = null;
+  this.dialogObserver = null;
+}
+
+/**
+ * The current context decides if commands are executed in chrome- or
+ * content space.
+ */
+Object.defineProperty(GeckoDriver.prototype, "context", {
+  get() {
+    return this._context;
+  },
+
+  set(context) {
+    this._context = lazy.Context.fromString(context);
+  },
+});
+
+/**
+ * The current WebDriver Session.
+ */
+Object.defineProperty(GeckoDriver.prototype, "currentSession", {
+  get() {
+    if (lazy.RemoteAgent.webDriverBiDi) {
+      return lazy.RemoteAgent.webDriverBiDi.session;
+    }
+
+    return this._currentSession;
+  },
+});
+
+/**
+ * Returns the current URL of the ChromeWindow or content browser,
+ * depending on context.
+ *
+ * @return {URL}
+ *     Read-only property containing the currently loaded URL.
+ */
+Object.defineProperty(GeckoDriver.prototype, "currentURL", {
+  get() {
+    const browsingContext = this.getBrowsingContext({ top: true });
+    return new URL(browsingContext.currentWindowGlobal.documentURI.spec);
+  },
+});
+
+/**
+ * Returns the title of the ChromeWindow or content browser,
+ * depending on context.
+ *
+ * @return {string}
+ *     Read-only property containing the title of the loaded URL.
+ */
+Object.defineProperty(GeckoDriver.prototype, "title", {
+  get() {
+    const browsingContext = this.getBrowsingContext({ top: true });
+    return browsingContext.currentWindowGlobal.documentTitle;
+  },
+});
+
+Object.defineProperty(GeckoDriver.prototype, "windowType", {
+  get() {
+    return this.curBrowser.window.document.documentElement.getAttribute(
+      "windowtype"
+    );
+  },
+});
+
+GeckoDriver.prototype.QueryInterface = ChromeUtils.generateQI([
+  "nsIObserver",
+  "nsISupportsWeakReference",
+]);
+
+/**
+ * Callback used to observe the creation of new modal or tab modal dialogs
+ * during the session's lifetime.
+ */
+GeckoDriver.prototype.handleModalDialog = function(action, dialog) {
+  if (!this.currentSession) {
+    return;
+  }
+
+  if (action === lazy.modal.ACTION_OPENED) {
+    this.dialog = new lazy.modal.Dialog(() => this.curBrowser, dialog);
+    this.getActor().notifyDialogOpened();
+  } else if (action === lazy.modal.ACTION_CLOSED) {
+    this.dialog = null;
+  }
+};
+
+/**
+ * Get the current visible URL.
+ */
+GeckoDriver.prototype._getCurrentURL = function() {
+  const browsingContext = this.getBrowsingContext({ top: true });
+  return new URL(browsingContext.currentURI.spec);
+};
+
+/**
+ * Get the current "MarionetteCommands" parent actor.
+ *
+ * @param {Object} options
+ * @param {boolean=} options.top
+ *     If set to true use the window's top-level browsing context for the actor,
+ *     otherwise the one from the currently selected frame. Defaults to false.
+ *
+ * @returns {MarionetteCommandsParent}
+ *     The parent actor.
+ */
+GeckoDriver.prototype.getActor = function(options = {}) {
+  return lazy.getMarionetteCommandsActorProxy(() =>
+    this.getBrowsingContext(options)
+  );
+};
+
+/**
+ * Get the selected BrowsingContext for the current context.
+ *
+ * @param {Object} options
+ * @param {Context=} options.context
+ *     Context (content or chrome) for which to retrieve the browsing context.
+ *     Defaults to the current one.
+ * @param {boolean=} options.parent
+ *     If set to true return the window's parent browsing context,
+ *     otherwise the one from the currently selected frame. Defaults to false.
+ * @param {boolean=} options.top
+ *     If set to true return the window's top-level browsing context,
+ *     otherwise the one from the currently selected frame. Defaults to false.
+ *
+ * @return {BrowsingContext}
+ *     The browsing context, or `null` if none is available
+ */
+GeckoDriver.prototype.getBrowsingContext = function(options = {}) {
+  const { context = this.context, parent = false, top = false } = options;
+
+  let browsingContext = null;
+  if (context === lazy.Context.Chrome) {
+    browsingContext = this.currentSession?.chromeBrowsingContext;
+  } else {
+    browsingContext = this.currentSession?.contentBrowsingContext;
+  }
+
+  if (browsingContext && parent) {
+    browsingContext = browsingContext.parent;
+  }
+
+  if (browsingContext && top) {
+    browsingContext = browsingContext.top;
+  }
+
+  return browsingContext;
+};
+
+/**
+ * Get the currently selected window.
+ *
+ * It will return the outer {@link ChromeWindow} previously selected by
+ * window handle through {@link #switchToWindow}, or the first window that
+ * was registered.
+ *
+ * @param {Object} options
+ * @param {Context=} options.context
+ *     Optional name of the context to use for finding the window.
+ *     It will be required if a command always needs a specific context,
+ *     whether which context is currently set. Defaults to the current
+ *     context.
+ *
+ * @return {ChromeWindow}
+ *     The current top-level browsing context.
+ */
+GeckoDriver.prototype.getCurrentWindow = function(options = {}) {
+  const { context = this.context } = options;
+
+  let win = null;
+  switch (context) {
+    case lazy.Context.Chrome:
+      if (this.curBrowser) {
+        win = this.curBrowser.window;
+      }
+      break;
+
+    case lazy.Context.Content:
+      if (this.curBrowser && this.curBrowser.contentBrowser) {
+        win = this.curBrowser.window;
+      }
+      break;
+  }
+
+  return win;
+};
+
+GeckoDriver.prototype.isReftestBrowser = function(element) {
+  return (
+    this._reftest &&
+    element &&
+    element.tagName === "xul:browser" &&
+    element.parentElement &&
+    element.parentElement.id === "reftest"
+  );
+};
+
+/**
+ * Create a new browsing context for window and add to known browsers.
+ *
+ * @param {ChromeWindow} win
+ *     Window for which we will create a browsing context.
+ *
+ * @return {string}
+ *     Returns the unique server-assigned ID of the window.
+ */
+GeckoDriver.prototype.addBrowser = function(win) {
+  let context = new lazy.browser.Context(win, this);
+  let winId = lazy.windowManager.getIdForWindow(win);
+
+  this.browsers[winId] = context;
+  this.curBrowser = this.browsers[winId];
+};
+
+/**
+ * Recursively get all labeled text.
+ *
+ * @param {Element} el
+ *     The parent element.
+ * @param {Array.<string>} lines
+ *      Array that holds the text lines.
+ */
+GeckoDriver.prototype.getVisibleText = function(el, lines) {
+  try {
+    if (lazy.atom.isElementDisplayed(el, this.getCurrentWindow())) {
+      if (el.value) {
+        lines.push(el.value);
+      }
+      for (let child in el.childNodes) {
+        this.getVisibleText(el.childNodes[child], lines);
+      }
+    }
+  } catch (e) {
+    if (el.nodeName == "#text") {
+      lines.push(el.textContent);
+    }
+  }
+};
+
+/**
+ * Handles registration of new content browsers.  Depending on
+ * their type they are either accepted or ignored.
+ *
+ * @param {xul:browser} browserElement
+ */
+GeckoDriver.prototype.registerBrowser = function(browserElement) {
+  // We want to ignore frames that are XUL browsers that aren't in the "main"
+  // tabbrowser, but accept things on Fennec (which doesn't have a
+  // xul:tabbrowser), and accept HTML iframes (because tests depend on it),
+  // as well as XUL frames. Ideally this should be cleaned up and we should
+  // keep track of browsers a different way.
+  if (
+    !lazy.AppInfo.isFirefox ||
+    browserElement.namespaceURI != XUL_NS ||
+    browserElement.nodeName != "browser" ||
+    browserElement.getTabBrowser()
+  ) {
+    this.curBrowser.register(browserElement);
+  }
+};
+
+/**
+ * Create a new WebDriver session.
+ *
+ * @param {Object} cmd
+ * @param {Object.<string, *>=} cmd.parameters
+ *     JSON Object containing any of the recognised capabilities as listed
+ *     on the `WebDriverSession` class.
+ *
+ * @return {Object}
+ *     Session ID and capabilities offered by the WebDriver service.
+ *
+ * @throws {SessionNotCreatedError}
+ *     If, for whatever reason, a session could not be created.
+ */
+GeckoDriver.prototype.newSession = async function(cmd) {
+  if (this.currentSession) {
+    throw new lazy.error.SessionNotCreatedError(
+      "Maximum number of active sessions"
+    );
+  }
+
+  const { parameters: capabilities } = cmd;
+
+  try {
+    // If the WebDriver BiDi protocol is active always use the Remote Agent
+    // to handle the WebDriver session. If it's not the case then Marionette
+    // itself needs to handle it, and has to nullify the "webSocketUrl"
+    // capability.
+    if (lazy.RemoteAgent.webDriverBiDi) {
+      await lazy.RemoteAgent.webDriverBiDi.createSession(capabilities);
+    } else {
+      this._currentSession = new lazy.WebDriverSession(capabilities);
+      this._currentSession.capabilities.delete("webSocketUrl");
+    }
+
+    // Don't wait for the initial window when Marionette is in windowless mode
+    if (!this.currentSession.capabilities.get("moz:windowless")) {
+      // Creating a WebDriver session too early can cause issues with
+      // clients in not being able to find any available window handle.
+      // Also when closing the application while it's still starting up can
+      // cause shutdown hangs. As such Marionette will return a new session
+      // once the initial application window has finished initializing.
+      lazy.logger.debug(`Waiting for initial application window`);
+      await lazy.Marionette.browserStartupFinished;
+
+      const appWin = await lazy.windowManager.waitForInitialApplicationWindowLoaded();
+
+      if (lazy.MarionettePrefs.clickToStart) {
+        Services.prompt.alert(
+          appWin,
+          "",
+          "Click to start execution of marionette tests"
+        );
+      }
+
+      this.addBrowser(appWin);
+      this.mainFrame = appWin;
+
+      // Setup observer for modal dialogs
+      this.dialogObserver = new lazy.modal.DialogObserver(
+        () => this.curBrowser
+      );
+      this.dialogObserver.add(this.handleModalDialog.bind(this));
+
+      for (let win of lazy.windowManager.windows) {
+        this.registerWindow(win, { registerBrowsers: true });
+      }
+
+      if (this.mainFrame) {
+        this.currentSession.chromeBrowsingContext = this.mainFrame.browsingContext;
+        this.mainFrame.focus();
+      }
+
+      if (this.curBrowser.tab) {
+        const browsingContext = this.curBrowser.contentBrowser.browsingContext;
+        this.currentSession.contentBrowsingContext = browsingContext;
+
+        await lazy.waitForInitialNavigationCompleted(
+          browsingContext.webProgress
+        );
+
+        this.curBrowser.contentBrowser.focus();
+      }
+
+      // Check if there is already an open dialog for the selected browser window.
+      this.dialog = lazy.modal.findModalDialogs(this.curBrowser);
+    }
+
+    lazy.registerCommandsActor();
+    lazy.enableEventsActor();
+
+    Services.obs.addObserver(this, TOPIC_BROWSER_READY);
+  } catch (e) {
+    throw new lazy.error.SessionNotCreatedError(e);
+  }
+
+  return {
+    sessionId: this.currentSession.id,
+    capabilities: this.currentSession.capabilities,
+  };
+};
+
+/**
+ * Start observing the specified window.
+ *
+ * @param {ChromeWindow} win
+ *     Chrome window to register event listeners for.
+ * @param {Object=} options
+ * @param {boolean=} options.registerBrowsers
+ *     If true, register all content browsers of found tabs. Defaults to false.
+ */
+GeckoDriver.prototype.registerWindow = function(win, options = {}) {
+  const { registerBrowsers = false } = options;
+  const tabBrowser = lazy.TabManager.getTabBrowser(win);
+
+  if (registerBrowsers && tabBrowser) {
+    for (const tab of tabBrowser.tabs) {
+      const contentBrowser = lazy.TabManager.getBrowserForTab(tab);
+      this.registerBrowser(contentBrowser);
+    }
+  }
+
+  // Listen for any kind of top-level process switch
+  tabBrowser?.addEventListener("XULFrameLoaderCreated", this);
+};
+
+/**
+ * Stop observing the specified window.
+ *
+ * @param {ChromeWindow} win
+ *     Chrome window to unregister event listeners for.
+ */
+GeckoDriver.prototype.stopObservingWindow = function(win) {
+  const tabBrowser = lazy.TabManager.getTabBrowser(win);
+
+  tabBrowser?.removeEventListener("XULFrameLoaderCreated", this);
+};
+
+GeckoDriver.prototype.handleEvent = function({ target, type }) {
+  switch (type) {
+    case "XULFrameLoaderCreated":
+      if (target === this.curBrowser.contentBrowser) {
+        lazy.logger.trace(
+          "Remoteness change detected. Set new top-level browsing context " +
+            `to ${target.browsingContext.id}`
+        );
+
+        this.currentSession.contentBrowsingContext = target.browsingContext;
+      }
+      break;
+  }
+};
+
+GeckoDriver.prototype.observe = function(subject, topic, data) {
+  switch (topic) {
+    case TOPIC_BROWSER_READY:
+      this.registerWindow(subject);
+      break;
+  }
+};
+
+/**
+ * Send the current session's capabilities to the client.
+ *
+ * Capabilities informs the client of which WebDriver features are
+ * supported by Firefox and Marionette.  They are immutable for the
+ * length of the session.
+ *
+ * The return value is an immutable map of string keys
+ * ("capabilities") to values, which may be of types boolean,
+ * numerical or string.
+ */
+GeckoDriver.prototype.getSessionCapabilities = function() {
+  return { capabilities: this.currentSession.capabilities };
+};
+
+/**
+ * Sets the context of the subsequent commands.
+ *
+ * All subsequent requests to commands that in some way involve
+ * interaction with a browsing context will target the chosen browsing
+ * context.
+ *
+ * @param {string} value
+ *     Name of the context to be switched to.  Must be one of "chrome" or
+ *     "content".
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>value</var> is not a string.
+ * @throws {WebDriverError}
+ *     If <var>value</var> is not a valid browsing context.
+ */
+GeckoDriver.prototype.setContext = function(cmd) {
+  let value = lazy.assert.string(cmd.parameters.value);
+
+  this.context = value;
+};
+
+/**
+ * Gets the context type that is Marionette's current target for
+ * browsing context scoped commands.
+ *
+ * You may choose a context through the {@link #setContext} command.
+ *
+ * The default browsing context is {@link Context.Content}.
+ *
+ * @return {Context}
+ *     Current context.
+ */
+GeckoDriver.prototype.getContext = function() {
+  return this.context;
+};
+
+/**
+ * Executes a JavaScript function in the context of the current browsing
+ * context, if in content space, or in chrome space otherwise, and returns
+ * the return value of the function.
+ *
+ * It is important to note that if the <var>sandboxName</var> parameter
+ * is left undefined, the script will be evaluated in a mutable sandbox,
+ * causing any change it makes on the global state of the document to have
+ * lasting side-effects.
+ *
+ * @param {string} script
+ *     Script to evaluate as a function body.
+ * @param {Array.<(string|boolean|number|object|WebReference)>} args
+ *     Arguments exposed to the script in <code>arguments</code>.
+ *     The array items must be serialisable to the WebDriver protocol.
+ * @param {string=} sandbox
+ *     Name of the sandbox to evaluate the script in.  The sandbox is
+ *     cached for later re-use on the same Window object if
+ *     <var>newSandbox</var> is false.  If he parameter is undefined,
+ *     the script is evaluated in a mutable sandbox.  If the parameter
+ *     is "system", it will be evaluted in a sandbox with elevated system
+ *     privileges, equivalent to chrome space.
+ * @param {boolean=} newSandbox
+ *     Forces the script to be evaluated in a fresh sandbox.  Note that if
+ *     it is undefined, the script will normally be evaluted in a fresh
+ *     sandbox.
+ * @param {string=} filename
+ *     Filename of the client's program where this script is evaluated.
+ * @param {number=} line
+ *     Line in the client's program where this script is evaluated.
+ *
+ * @return {(string|boolean|number|object|WebReference)}
+ *     Return value from the script, or null which signifies either the
+ *     JavaScript notion of null or undefined.
+ *
+ * @throws {JavaScriptError}
+ *     If an {@link Error} was thrown whilst evaluating the script.
+ * @throws {NoSuchElementError}
+ *     If an element that was passed as part of <var>args</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {ScriptTimeoutError}
+ *     If the script was interrupted due to reaching the session's
+ *     script timeout.
+ * @throws {StaleElementReferenceError}
+ *     If an element that was passed as part of <var>args</var> or that is
+ *     returned as result has gone stale.
+ */
+GeckoDriver.prototype.executeScript = async function(cmd) {
+  let { script, args } = cmd.parameters;
+  let opts = {
+    script: cmd.parameters.script,
+    args: cmd.parameters.args,
+    sandboxName: cmd.parameters.sandbox,
+    newSandbox: cmd.parameters.newSandbox,
+    file: cmd.parameters.filename,
+    line: cmd.parameters.line,
+  };
+
+  return { value: await this.execute_(script, args, opts) };
+};
+
+/**
+ * Executes a JavaScript function in the context of the current browsing
+ * context, if in content space, or in chrome space otherwise, and returns
+ * the object passed to the callback.
+ *
+ * The callback is always the last argument to the <var>arguments</var>
+ * list passed to the function scope of the script.  It can be retrieved
+ * as such:
+ *
+ * <pre><code>
+ *     let callback = arguments[arguments.length - 1];
+ *     callback("foo");
+ *     // "foo" is returned
+ * </code></pre>
+ *
+ * It is important to note that if the <var>sandboxName</var> parameter
+ * is left undefined, the script will be evaluated in a mutable sandbox,
+ * causing any change it makes on the global state of the document to have
+ * lasting side-effects.
+ *
+ * @param {string} script
+ *     Script to evaluate as a function body.
+ * @param {Array.<(string|boolean|number|object|WebReference)>} args
+ *     Arguments exposed to the script in <code>arguments</code>.
+ *     The array items must be serialisable to the WebDriver protocol.
+ * @param {string=} sandbox
+ *     Name of the sandbox to evaluate the script in.  The sandbox is
+ *     cached for later re-use on the same Window object if
+ *     <var>newSandbox</var> is false.  If the parameter is undefined,
+ *     the script is evaluated in a mutable sandbox.  If the parameter
+ *     is "system", it will be evaluted in a sandbox with elevated system
+ *     privileges, equivalent to chrome space.
+ * @param {boolean=} newSandbox
+ *     Forces the script to be evaluated in a fresh sandbox.  Note that if
+ *     it is undefined, the script will normally be evaluted in a fresh
+ *     sandbox.
+ * @param {string=} filename
+ *     Filename of the client's program where this script is evaluated.
+ * @param {number=} line
+ *     Line in the client's program where this script is evaluated.
+ *
+ * @return {(string|boolean|number|object|WebReference)}
+ *     Return value from the script, or null which signifies either the
+ *     JavaScript notion of null or undefined.
+ *
+ * @throws {JavaScriptError}
+ *     If an Error was thrown whilst evaluating the script.
+ * @throws {NoSuchElementError}
+ *     If an element that was passed as part of <var>args</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {ScriptTimeoutError}
+ *     If the script was interrupted due to reaching the session's
+ *     script timeout.
+ * @throws {StaleElementReferenceError}
+ *     If an element that was passed as part of <var>args</var> or that is
+ *     returned as result has gone stale.
+ */
+GeckoDriver.prototype.executeAsyncScript = async function(cmd) {
+  let { script, args } = cmd.parameters;
+  let opts = {
+    script: cmd.parameters.script,
+    args: cmd.parameters.args,
+    sandboxName: cmd.parameters.sandbox,
+    newSandbox: cmd.parameters.newSandbox,
+    file: cmd.parameters.filename,
+    line: cmd.parameters.line,
+    async: true,
+  };
+
+  return { value: await this.execute_(script, args, opts) };
+};
+
+GeckoDriver.prototype.execute_ = async function(
+  script,
+  args = [],
+  {
+    sandboxName = null,
+    newSandbox = false,
+    file = "",
+    line = 0,
+    async = false,
+  } = {}
+) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  lazy.assert.string(
+    script,
+    lazy.pprint`Expected "script" to be a string: ${script}`
+  );
+  lazy.assert.array(
+    args,
+    lazy.pprint`Expected script args to be an array: ${args}`
+  );
+  if (sandboxName !== null) {
+    lazy.assert.string(
+      sandboxName,
+      lazy.pprint`Expected sandbox name to be a string: ${sandboxName}`
+    );
+  }
+  lazy.assert.boolean(
+    newSandbox,
+    lazy.pprint`Expected newSandbox to be boolean: ${newSandbox}`
+  );
+  lazy.assert.string(file, lazy.pprint`Expected file to be a string: ${file}`);
+  lazy.assert.number(line, lazy.pprint`Expected line to be a number: ${line}`);
+
+  let opts = {
+    timeout: this.currentSession.timeouts.script,
+    sandboxName,
+    newSandbox,
+    file,
+    line,
+    async,
+  };
+
+  return this.getActor().executeScript(script, args, opts);
+};
+
+/**
+ * Navigate to given URL.
+ *
+ * Navigates the current browsing context to the given URL and waits for
+ * the document to load or the session's page timeout duration to elapse
+ * before returning.
+ *
+ * The command will return with a failure if there is an error loading
+ * the document or the URL is blocked.  This can occur if it fails to
+ * reach host, the URL is malformed, or if there is a certificate issue
+ * to name some examples.
+ *
+ * The document is considered successfully loaded when the
+ * DOMContentLoaded event on the frame element associated with the
+ * current window triggers and document.readyState is "complete".
+ *
+ * In chrome context it will change the current window's location to
+ * the supplied URL and wait until document.readyState equals "complete"
+ * or the page timeout duration has elapsed.
+ *
+ * @param {string} url
+ *     URL to navigate to.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.navigateTo = async function(cmd) {
+  lazy.assert.content(this.context);
+  const browsingContext = lazy.assert.open(
+    this.getBrowsingContext({ top: true })
+  );
+  await this._handleUserPrompts();
+
+  let validURL;
+  try {
+    validURL = new URL(cmd.parameters.url);
+  } catch (e) {
+    throw new lazy.error.InvalidArgumentError(`Malformed URL: ${e.message}`);
+  }
+
+  // Switch to the top-level browsing context before navigating
+  this.currentSession.contentBrowsingContext = browsingContext;
+
+  const loadEventExpected = lazy.navigate.isLoadEventExpected(
+    this._getCurrentURL(),
+    {
+      future: validURL,
+    }
+  );
+
+  await lazy.navigate.waitForNavigationCompleted(
+    this,
+    () => {
+      lazy.navigate.navigateTo(browsingContext, validURL);
+    },
+    { loadEventExpected }
+  );
+
+  this.curBrowser.contentBrowser.focus();
+};
+
+/**
+ * Get a string representing the current URL.
+ *
+ * On Desktop this returns a string representation of the URL of the
+ * current top level browsing context.  This is equivalent to
+ * document.location.href.
+ *
+ * When in the context of the chrome, this returns the canonical URL
+ * of the current resource.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getCurrentUrl = async function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  return this._getCurrentURL().href;
+};
+
+/**
+ * Gets the current title of the window.
+ *
+ * @return {string}
+ *     Document title of the top-level browsing context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getTitle = async function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  return this.title;
+};
+
+/**
+ * Gets the current type of the window.
+ *
+ * @return {string}
+ *     Type of window
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.getWindowType = function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+
+  return this.windowType;
+};
+
+/**
+ * Gets the page source of the content document.
+ *
+ * @return {string}
+ *     String serialisation of the DOM of the current browsing context's
+ *     active document.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getPageSource = async function() {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  return this.getActor().getPageSource();
+};
+
+/**
+ * Cause the browser to traverse one step backward in the joint history
+ * of the current browsing context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.goBack = async function() {
+  lazy.assert.content(this.context);
+  const browsingContext = lazy.assert.open(
+    this.getBrowsingContext({ top: true })
+  );
+  await this._handleUserPrompts();
+
+  // If there is no history, just return
+  if (!browsingContext.embedderElement?.canGoBack) {
+    return;
+  }
+
+  await lazy.navigate.waitForNavigationCompleted(this, () => {
+    browsingContext.goBack();
+  });
+};
+
+/**
+ * Cause the browser to traverse one step forward in the joint history
+ * of the current browsing context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.goForward = async function() {
+  lazy.assert.content(this.context);
+  const browsingContext = lazy.assert.open(
+    this.getBrowsingContext({ top: true })
+  );
+  await this._handleUserPrompts();
+
+  // If there is no history, just return
+  if (!browsingContext.embedderElement?.canGoForward) {
+    return;
+  }
+
+  await lazy.navigate.waitForNavigationCompleted(this, () => {
+    browsingContext.goForward();
+  });
+};
+
+/**
+ * Causes the browser to reload the page in current top-level browsing
+ * context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.refresh = async function() {
+  lazy.assert.content(this.context);
+  const browsingContext = lazy.assert.open(
+    this.getBrowsingContext({ top: true })
+  );
+  await this._handleUserPrompts();
+
+  // Switch to the top-level browsing context before navigating
+  this.currentSession.contentBrowsingContext = browsingContext;
+
+  await lazy.navigate.waitForNavigationCompleted(this, () => {
+    lazy.navigate.refresh(browsingContext);
+  });
+};
+
+/**
+ * Get the current window's handle. On desktop this typically corresponds
+ * to the currently selected tab.
+ *
+ * For chrome scope it returns the window identifier for the current chrome
+ * window for tests interested in managing the chrome window and tab separately.
+ *
+ * Return an opaque server-assigned identifier to this window that
+ * uniquely identifies it within this Marionette instance.  This can
+ * be used to switch to this window at a later point.
+ *
+ * @return {string}
+ *     Unique window handle.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.getWindowHandle = function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+
+  if (this.context == lazy.Context.Chrome) {
+    return lazy.windowManager.getIdForWindow(this.curBrowser.window);
+  }
+  return lazy.TabManager.getIdForBrowser(this.curBrowser.contentBrowser);
+};
+
+/**
+ * Get a list of top-level browsing contexts. On desktop this typically
+ * corresponds to the set of open tabs for browser windows, or the window
+ * itself for non-browser chrome windows.
+ *
+ * For chrome scope it returns identifiers for each open chrome window for
+ * tests interested in managing a set of chrome windows and tabs separately.
+ *
+ * Each window handle is assigned by the server and is guaranteed unique,
+ * however the return array does not have a specified ordering.
+ *
+ * @return {Array.<string>}
+ *     Unique window handles.
+ */
+GeckoDriver.prototype.getWindowHandles = function() {
+  if (this.context == lazy.Context.Chrome) {
+    return lazy.windowManager.chromeWindowHandles.map(String);
+  }
+  return lazy.TabManager.allBrowserUniqueIds.map(String);
+};
+
+/**
+ * Get the current position and size of the browser window currently in focus.
+ *
+ * Will return the current browser window size in pixels. Refers to
+ * window outerWidth and outerHeight values, which include scroll bars,
+ * title bars, etc.
+ *
+ * @return {Object.<string, number>}
+ *     Object with |x| and |y| coordinates, and |width| and |height|
+ *     of browser window.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getWindowRect = async function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  return this.curBrowser.rect;
+};
+
+/**
+ * Set the window position and size of the browser on the operating
+ * system window manager.
+ *
+ * The supplied `width` and `height` values refer to the window `outerWidth`
+ * and `outerHeight` values, which include browser chrome and OS-level
+ * window borders.
+ *
+ * @param {number} x
+ *     X coordinate of the top/left of the window that it will be
+ *     moved to.
+ * @param {number} y
+ *     Y coordinate of the top/left of the window that it will be
+ *     moved to.
+ * @param {number} width
+ *     Width to resize the window to.
+ * @param {number} height
+ *     Height to resize the window to.
+ *
+ * @return {Object.<string, number>}
+ *     Object with `x` and `y` coordinates and `width` and `height`
+ *     dimensions.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not applicable to application.
+ */
+GeckoDriver.prototype.setWindowRect = async function(cmd) {
+  lazy.assert.desktop();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  const { x = null, y = null, width = null, height = null } = cmd.parameters;
+  if (x !== null) {
+    lazy.assert.integer(x);
+  }
+  if (y !== null) {
+    lazy.assert.integer(y);
+  }
+  if (height !== null) {
+    lazy.assert.positiveInteger(height);
+  }
+  if (width !== null) {
+    lazy.assert.positiveInteger(width);
+  }
+
+  const win = this.getCurrentWindow();
+  switch (lazy.WindowState.from(win.windowState)) {
+    case lazy.WindowState.Fullscreen:
+      await exitFullscreen(win);
+      break;
+
+    case lazy.WindowState.Maximized:
+    case lazy.WindowState.Minimized:
+      await restoreWindow(win);
+      break;
+  }
+
+  function geometryMatches() {
+    if (
+      width !== null &&
+      height !== null &&
+      (win.outerWidth !== width || win.outerHeight !== height)
+    ) {
+      return false;
+    }
+    if (x !== null && y !== null && (win.screenX !== x || win.screenY !== y)) {
+      return false;
+    }
+    lazy.logger.trace(`Requested window geometry matches`);
+    return true;
+  }
+
+  if (!geometryMatches()) {
+    // There might be more than one resize or MozUpdateWindowPos event due
+    // to previous geometry changes, such as from restoreWindow(), so
+    // wait longer if window geometry does not match.
+    const options = { checkFn: geometryMatches, timeout: 500 };
+    const promises = [];
+    if (width !== null && height !== null) {
+      promises.push(new lazy.EventPromise(win, "resize", options));
+      win.resizeTo(width, height);
+    }
+    if (x !== null && y !== null) {
+      promises.push(
+        new lazy.EventPromise(win.windowRoot, "MozUpdateWindowPos", options)
+      );
+      win.moveTo(x, y);
+    }
+    try {
+      await Promise.race(promises);
+    } catch (e) {
+      if (e instanceof lazy.error.TimeoutError) {
+        // The operating system might not honor the move or resize, in which
+        // case assume that geometry will have been adjusted "as close as
+        // possible" to that requested.  There may be no event received if the
+        // geometry is already as close as possible.
+      } else {
+        throw e;
+      }
+    }
+  }
+
+  return this.curBrowser.rect;
+};
+
+/**
+ * Switch current top-level browsing context by name or server-assigned
+ * ID.  Searches for windows by name, then ID.  Content windows take
+ * precedence.
+ *
+ * @param {string} handle
+ *     Handle of the window to switch to.
+ * @param {boolean=} focus
+ *     A boolean value which determines whether to focus
+ *     the window. Defaults to true.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>handle</var> is not a string or <var>focus</var> not a boolean.
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.switchToWindow = async function(cmd) {
+  const { focus = true, handle } = cmd.parameters;
+
+  lazy.assert.string(
+    handle,
+    lazy.pprint`Expected "handle" to be a string, got ${handle}`
+  );
+  lazy.assert.boolean(
+    focus,
+    lazy.pprint`Expected "focus" to be a boolean, got ${focus}`
+  );
+
+  const found = lazy.windowManager.findWindowByHandle(handle);
+
+  let selected = false;
+  if (found) {
+    try {
+      await this.setWindowHandle(found, focus);
+      selected = true;
+    } catch (e) {
+      lazy.logger.error(e);
+    }
+  }
+
+  if (!selected) {
+    throw new lazy.error.NoSuchWindowError(
+      `Unable to locate window: ${handle}`
+    );
+  }
+};
+
+/**
+ * Switch the marionette window to a given window. If the browser in
+ * the window is unregistered, register that browser and wait for
+ * the registration is complete. If |focus| is true then set the focus
+ * on the window.
+ *
+ * @param {Object} winProperties
+ *     Object containing window properties such as returned from
+ *     :js:func:`GeckoDriver#getWindowProperties`
+ * @param {boolean=} focus
+ *     A boolean value which determines whether to focus the window.
+ *     Defaults to true.
+ */
+GeckoDriver.prototype.setWindowHandle = async function(
+  winProperties,
+  focus = true
+) {
+  if (!(winProperties.id in this.browsers)) {
+    // Initialise Marionette if the current chrome window has not been seen
+    // before. Also register the initial tab, if one exists.
+    this.addBrowser(winProperties.win);
+    this.mainFrame = winProperties.win;
+
+    this.currentSession.chromeBrowsingContext = this.mainFrame.browsingContext;
+
+    if (!winProperties.hasTabBrowser) {
+      this.currentSession.contentBrowsingContext = null;
+    } else {
+      const tabBrowser = lazy.TabManager.getTabBrowser(winProperties.win);
+
+      // For chrome windows such as a reftest window, `getTabBrowser` is not
+      // a tabbrowser, it is the content browser which should be used here.
+      const contentBrowser = tabBrowser.tabs
+        ? tabBrowser.selectedBrowser
+        : tabBrowser;
+
+      this.currentSession.contentBrowsingContext =
+        contentBrowser.browsingContext;
+      this.registerBrowser(contentBrowser);
+    }
+  } else {
+    // Otherwise switch to the known chrome window
+    this.curBrowser = this.browsers[winProperties.id];
+    this.mainFrame = this.curBrowser.window;
+
+    // Activate the tab if it's a content window.
+    let tab = null;
+    if (winProperties.hasTabBrowser) {
+      tab = await this.curBrowser.switchToTab(
+        winProperties.tabIndex,
+        winProperties.win,
+        focus
+      );
+    }
+
+    this.currentSession.chromeBrowsingContext = this.mainFrame.browsingContext;
+    this.currentSession.contentBrowsingContext =
+      tab?.linkedBrowser.browsingContext;
+  }
+
+  // Check for existing dialogs for the new window
+  this.dialog = lazy.modal.findModalDialogs(this.curBrowser);
+
+  // If there is an open window modal dialog the underlying chrome window
+  // cannot be focused.
+  if (focus && !this.dialog?.isWindowModal) {
+    await this.curBrowser.focusWindow();
+  }
+};
+
+/**
+ * Set the current browsing context for future commands to the parent
+ * of the current browsing context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.switchToParentFrame = async function() {
+  let browsingContext = this.getBrowsingContext();
+  if (browsingContext && !browsingContext.parent) {
+    return;
+  }
+
+  browsingContext = lazy.assert.open(browsingContext?.parent);
+
+  this.currentSession.contentBrowsingContext = browsingContext;
+};
+
+/**
+ * Switch to a given frame within the current window.
+ *
+ * @param {(string|Object)=} element
+ *     A web element reference of the frame or its element id.
+ * @param {number=} id
+ *     The index of the frame to switch to.
+ *     If both element and id are not defined, switch to top-level frame.
+ *
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>element</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>element</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.switchToFrame = async function(cmd) {
+  const { element: el, id } = cmd.parameters;
+
+  if (typeof id == "number") {
+    lazy.assert.unsignedShort(
+      id,
+      `Expected id to be unsigned short, got ${id}`
+    );
+  }
+
+  const top = id == null && el == null;
+  lazy.assert.open(this.getBrowsingContext({ top }));
+  await this._handleUserPrompts();
+
+  // Bug 1495063: Elements should be passed as WebReference reference
+  let byFrame;
+  if (typeof el == "string") {
+    byFrame = WebReference.fromUUID(el).toJSON();
+  } else if (el) {
+    byFrame = el;
+  }
+
+  const { browsingContext } = await this.getActor({ top }).switchToFrame(
+    byFrame || id
+  );
+
+  this.currentSession.contentBrowsingContext = browsingContext;
+};
+
+GeckoDriver.prototype.getTimeouts = function() {
+  return this.currentSession.timeouts;
+};
+
+/**
+ * Set timeout for page loading, searching, and scripts.
+ *
+ * @param {Object.<string, number>}
+ *     Dictionary of timeout types and their new value, where all timeout
+ *     types are optional.
+ *
+ * @throws {InvalidArgumentError}
+ *     If timeout type key is unknown, or the value provided with it is
+ *     not an integer.
+ */
+GeckoDriver.prototype.setTimeouts = function(cmd) {
+  // merge with existing timeouts
+  let merged = Object.assign(
+    this.currentSession.timeouts.toJSON(),
+    cmd.parameters
+  );
+
+  this.currentSession.timeouts = lazy.Timeouts.fromJSON(merged);
+};
+
+/** Single tap. */
+GeckoDriver.prototype.singleTap = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+
+  let { id, x, y } = cmd.parameters;
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  await this.getActor().singleTap(
+    webEl,
+    x,
+    y,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * Perform a series of grouped actions at the specified points in time.
+ *
+ * @param {Array.<?>} actions
+ *     Array of objects that each represent an action sequence.
+ *
+ * @throws {NoSuchElementError}
+ *     If an element that is used as part of the action chain is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If an element that is used as part of the action chain has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not yet available in current context.
+ */
+GeckoDriver.prototype.performActions = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  const actions = cmd.parameters.actions;
+
+  await this.getActor().performActions(
+    actions,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * Release all the keys and pointer buttons that are currently depressed.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.releaseActions = async function() {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  await this.getActor().releaseActions();
+};
+
+/**
+ * Find an element using the indicated search strategy.
+ *
+ * @param {string=} element
+ *     Web element reference ID to the element that will be used as start node.
+ * @param {string} using
+ *     Indicates which search method to use.
+ * @param {string} value
+ *     Value the client is looking for.
+ *
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>element</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>element</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.findElement = async function(cmd) {
+  const { element: el, using, value } = cmd.parameters;
+
+  if (!SUPPORTED_STRATEGIES.has(using)) {
+    throw new lazy.error.InvalidSelectorError(
+      `Strategy not supported: ${using}`
+    );
+  }
+
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let startNode;
+  if (typeof el != "undefined") {
+    startNode = WebReference.fromUUID(el).toJSON();
+  }
+
+  let opts = {
+    startNode,
+    timeout: this.currentSession.timeouts.implicit,
+    all: false,
+  };
+
+  return this.getActor().findElement(using, value, opts);
+};
+
+/**
+ * Find elements using the indicated search strategy.
+ *
+ * @param {string=} element
+ *     Web element reference ID to the element that will be used as start node.
+ * @param {string} using
+ *     Indicates which search method to use.
+ * @param {string} value
+ *     Value the client is looking for.
+ *
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>element</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>element</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.findElements = async function(cmd) {
+  const { element: el, using, value } = cmd.parameters;
+
+  if (!SUPPORTED_STRATEGIES.has(using)) {
+    throw new lazy.error.InvalidSelectorError(
+      `Strategy not supported: ${using}`
+    );
+  }
+
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let startNode;
+  if (typeof el != "undefined") {
+    startNode = WebReference.fromUUID(el).toJSON();
+  }
+
+  let opts = {
+    startNode,
+    timeout: this.currentSession.timeouts.implicit,
+    all: true,
+  };
+
+  return this.getActor().findElements(using, value, opts);
+};
+
+/**
+ * Return the shadow root of an element in the document.
+ *
+ * @param {id}
+ *     A web element id reference.
+ * @return {ShadowRoot}
+ *     ShadowRoot of the element.
+ *
+ * @throws {InvalidArgumentError}
+ *     If element <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchShadowRoot}
+ *     Element does not have a shadow root attached.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in chrome current context.
+ */
+GeckoDriver.prototype.getShadowRoot = async function(cmd) {
+  // Bug 1743541: Add support for chrome scope.
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(
+    cmd.parameters.id,
+    lazy.pprint`Expected "id" to be a string, got ${cmd.parameters.id}`
+  );
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getShadowRoot(webEl);
+};
+
+/**
+ * Return the active element in the document.
+ *
+ * @return {WebReference}
+ *     Active element of the current browsing context's document
+ *     element, if the document element is non-null.
+ *
+ * @throws {NoSuchElementError}
+ *     If the document does not have an active element, i.e. if
+ *     its document element has been deleted.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in chrome context.
+ */
+GeckoDriver.prototype.getActiveElement = async function() {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  return this.getActor().getActiveElement();
+};
+
+/**
+ * Send click event to element.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be clicked.
+ *
+ * @throws {InvalidArgumentError}
+ *     If element <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.clickElement = async function(cmd) {
+  const browsingContext = lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  const actor = this.getActor();
+
+  const loadEventExpected = lazy.navigate.isLoadEventExpected(
+    this._getCurrentURL(),
+    {
+      browsingContext,
+      target: await actor.getElementAttribute(webEl, "target"),
+    }
+  );
+
+  await lazy.navigate.waitForNavigationCompleted(
+    this,
+    () => actor.clickElement(webEl, this.currentSession.capabilities),
+    {
+      loadEventExpected,
+      // The click might trigger a navigation, so don't count on it.
+      requireBeforeUnload: false,
+    }
+  );
+};
+
+/**
+ * Get a given attribute of an element.
+ *
+ * @param {string} id
+ *     Web element reference ID to the element that will be inspected.
+ * @param {string} name
+ *     Name of the attribute which value to retrieve.
+ *
+ * @return {string}
+ *     Value of the attribute.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> or <var>name</var> are not strings.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementAttribute = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  const id = lazy.assert.string(cmd.parameters.id);
+  const name = lazy.assert.string(cmd.parameters.name);
+  const webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementAttribute(webEl, name);
+};
+
+/**
+ * Returns the value of a property associated with given element.
+ *
+ * @param {string} id
+ *     Web element reference ID to the element that will be inspected.
+ * @param {string} name
+ *     Name of the property which value to retrieve.
+ *
+ * @return {string}
+ *     Value of the property.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> or <var>name</var> are not strings.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementProperty = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  const id = lazy.assert.string(cmd.parameters.id);
+  const name = lazy.assert.string(cmd.parameters.name);
+  const webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementProperty(webEl, name);
+};
+
+/**
+ * Get the text of an element, if any.  Includes the text of all child
+ * elements.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be inspected.
+ *
+ * @return {string}
+ *     Element's text "as rendered".
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementText = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementText(webEl);
+};
+
+/**
+ * Get the tag name of the element.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be inspected.
+ *
+ * @return {string}
+ *     Local tag name of element.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementTagName = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementTagName(webEl);
+};
+
+/**
+ * Check if element is displayed.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be inspected.
+ *
+ * @return {boolean}
+ *     True if displayed, false otherwise.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.isElementDisplayed = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().isElementDisplayed(
+    webEl,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * Return the property of the computed style of an element.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be checked.
+ * @param {string} propertyName
+ *     CSS rule that is being requested.
+ *
+ * @return {string}
+ *     Value of |propertyName|.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> or <var>propertyName</var> are not strings.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementValueOfCssProperty = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let prop = lazy.assert.string(cmd.parameters.propertyName);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementValueOfCssProperty(webEl, prop);
+};
+
+/**
+ * Check if element is enabled.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be checked.
+ *
+ * @return {boolean}
+ *     True if enabled, false if disabled.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.isElementEnabled = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().isElementEnabled(
+    webEl,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * Check if element is selected.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be checked.
+ *
+ * @return {boolean}
+ *     True if selected, false if unselected.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.isElementSelected = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().isElementSelected(
+    webEl,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.getElementRect = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().getElementRect(webEl);
+};
+
+/**
+ * Send key presses to element after focusing on it.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be checked.
+ * @param {string} text
+ *     Value to send to the element.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> or <var>text</var> are not strings.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.sendKeysToElement = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let text = lazy.assert.string(cmd.parameters.text);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  return this.getActor().sendKeysToElement(
+    webEl,
+    text,
+    this.currentSession.capabilities
+  );
+};
+
+/**
+ * Clear the text of an element.
+ *
+ * @param {string} id
+ *     Reference ID to the element that will be cleared.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>id</var> is not a string.
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.clearElement = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let id = lazy.assert.string(cmd.parameters.id);
+  let webEl = WebReference.fromUUID(id).toJSON();
+
+  await this.getActor().clearElement(webEl);
+};
+
+/**
+ * Add a single cookie to the cookie store associated with the active
+ * document's address.
+ *
+ * @param {Map.<string, (string|number|boolean)>} cookie
+ *     Cookie object.
+ *
+ * @throws {InvalidCookieDomainError}
+ *     If <var>cookie</var> is for a different domain than the active
+ *     document's host.
+ * @throws {NoSuchWindowError}
+ *     Bbrowsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.addCookie = async function(cmd) {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let { protocol, hostname } = this._getCurrentURL();
+
+  const networkSchemes = ["http:", "https:"];
+  if (!networkSchemes.includes(protocol)) {
+    throw new lazy.error.InvalidCookieDomainError("Document is cookie-averse");
+  }
+
+  let newCookie = lazy.cookie.fromJSON(cmd.parameters.cookie);
+
+  lazy.cookie.add(newCookie, { restrictToHost: hostname, protocol });
+};
+
+/**
+ * Get all the cookies for the current domain.
+ *
+ * This is the equivalent of calling <code>document.cookie</code> and
+ * parsing the result.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.getCookies = async function() {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let { hostname, pathname } = this._getCurrentURL();
+  return [...lazy.cookie.iter(hostname, pathname)];
+};
+
+/**
+ * Delete all cookies that are visible to a document.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.deleteAllCookies = async function() {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let { hostname, pathname } = this._getCurrentURL();
+  for (let toDelete of lazy.cookie.iter(hostname, pathname)) {
+    lazy.cookie.remove(toDelete);
+  }
+};
+
+/**
+ * Delete a cookie by name.
+ *
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in current context.
+ */
+GeckoDriver.prototype.deleteCookie = async function(cmd) {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext());
+  await this._handleUserPrompts();
+
+  let { hostname, pathname } = this._getCurrentURL();
+  let name = lazy.assert.string(cmd.parameters.name);
+  for (let c of lazy.cookie.iter(hostname, pathname)) {
+    if (c.name === name) {
+      lazy.cookie.remove(c);
+    }
+  }
+};
+
+/**
+ * Open a new top-level browsing context.
+ *
+ * @param {string=} type
+ *     Optional type of the new top-level browsing context. Can be one of
+ *     `tab` or `window`. Defaults to `tab`.
+ * @param {boolean=} focus
+ *     Optional flag if the new top-level browsing context should be opened
+ *     in foreground (focused) or background (not focused). Defaults to false.
+ * @param {boolean=} private
+ *     Optional flag, which gets only evaluated for type `window`. True if the
+ *     new top-level browsing context should be a private window.
+ *     Defaults to false.
+ *
+ * @return {Object.<string, string>}
+ *     Handle and type of the new browsing context.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.newWindow = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  let focus = false;
+  if (typeof cmd.parameters.focus != "undefined") {
+    focus = lazy.assert.boolean(
+      cmd.parameters.focus,
+      lazy.pprint`Expected "focus" to be a boolean, got ${cmd.parameters.focus}`
+    );
+  }
+
+  let isPrivate = false;
+  if (typeof cmd.parameters.private != "undefined") {
+    isPrivate = lazy.assert.boolean(
+      cmd.parameters.private,
+      lazy.pprint`Expected "private" to be a boolean, got ${cmd.parameters.private}`
+    );
+  }
+
+  let type;
+  if (typeof cmd.parameters.type != "undefined") {
+    type = lazy.assert.string(
+      cmd.parameters.type,
+      lazy.pprint`Expected "type" to be a string, got ${cmd.parameters.type}`
+    );
+  }
+
+  // If an invalid or no type has been specified default to a tab.
+  if (typeof type == "undefined" || !["tab", "window"].includes(type)) {
+    type = "tab";
+  }
+
+  let contentBrowser;
+
+  switch (type) {
+    case "window":
+      let win = await this.curBrowser.openBrowserWindow(focus, isPrivate);
+      contentBrowser = lazy.TabManager.getTabBrowser(win).selectedBrowser;
+      break;
+
+    default:
+      // To not fail if a new type gets added in the future, make opening
+      // a new tab the default action.
+      let tab = await this.curBrowser.openTab(focus);
+      contentBrowser = lazy.TabManager.getBrowserForTab(tab);
+  }
+
+  // Actors need the new window to be loaded to safely execute queries.
+  // Wait until the initial page load has been finished.
+  await lazy.waitForInitialNavigationCompleted(
+    contentBrowser.browsingContext.webProgress
+  );
+
+  const id = lazy.TabManager.getIdForBrowser(contentBrowser);
+
+  return { handle: id.toString(), type };
+};
+
+/**
+ * Close the currently selected tab/window.
+ *
+ * With multiple open tabs present the currently selected tab will
+ * be closed.  Otherwise the window itself will be closed. If it is the
+ * last window currently open, the window will not be closed to prevent
+ * a shutdown of the application. Instead the returned list of window
+ * handles is empty.
+ *
+ * @return {Array.<string>}
+ *     Unique window handles of remaining windows.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ */
+GeckoDriver.prototype.close = async function() {
+  lazy.assert.open(
+    this.getBrowsingContext({ context: lazy.Context.Content, top: true })
+  );
+  await this._handleUserPrompts();
+
+  // If there is only one window left, do not close unless windowless mode is
+  // enabled. Instead return a faked empty array of window handles.
+  // This will instruct geckodriver to terminate the application.
+  if (
+    lazy.TabManager.getTabCount() === 1 &&
+    !this.currentSession.capabilities.get("moz:windowless")
+  ) {
+    return [];
+  }
+
+  await this.curBrowser.closeTab();
+  this.currentSession.contentBrowsingContext = null;
+
+  return lazy.TabManager.allBrowserUniqueIds.map(String);
+};
+
+/**
+ * Close the currently selected chrome window.
+ *
+ * If it is the last window currently open, the chrome window will not be
+ * closed to prevent a shutdown of the application. Instead the returned
+ * list of chrome window handles is empty.
+ *
+ * @return {Array.<string>}
+ *     Unique chrome window handles of remaining chrome windows.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.closeChromeWindow = async function() {
+  lazy.assert.desktop();
+  lazy.assert.open(
+    this.getBrowsingContext({ context: lazy.Context.Chrome, top: true })
+  );
+
+  let nwins = 0;
+
+  // eslint-disable-next-line
+  for (let _ of lazy.windowManager.windows) {
+    nwins++;
+  }
+
+  // If there is only one window left, do not close unless windowless mode is
+  // enabled. Instead return a faked empty array of window handles.
+  // This will instruct geckodriver to terminate the application.
+  if (nwins == 1 && !this.currentSession.capabilities.get("moz:windowless")) {
+    return [];
+  }
+
+  await this.curBrowser.closeWindow();
+  this.currentSession.chromeBrowsingContext = null;
+  this.currentSession.contentBrowsingContext = null;
+
+  return lazy.windowManager.chromeWindowHandles.map(String);
+};
+
+/** Delete Marionette session. */
+GeckoDriver.prototype.deleteSession = function() {
+  if (!this.currentSession) {
+    return;
+  }
+
+  for (let win of lazy.windowManager.windows) {
+    this.stopObservingWindow(win);
+  }
+
+  // reset to the top-most frame
+  this.mainFrame = null;
+
+  if (this.dialogObserver) {
+    this.dialogObserver.cleanup();
+    this.dialogObserver = null;
+  }
+
+  try {
+    Services.obs.removeObserver(this, TOPIC_BROWSER_READY);
+  } catch (e) {
+    lazy.logger.debug(`Failed to remove observer "${TOPIC_BROWSER_READY}"`);
+  }
+
+  // Always unregister actors after all other observers
+  // and listeners have been removed.
+  lazy.unregisterCommandsActor();
+  // MarionetteEvents actors are only disabled to avoid IPC errors if there are
+  // in flight events being forwarded from the content process to the parent
+  // process.
+  lazy.disableEventsActor();
+
+  if (lazy.RemoteAgent.webDriverBiDi) {
+    lazy.RemoteAgent.webDriverBiDi.deleteSession();
+  } else {
+    this.currentSession.destroy();
+    this._currentSession = null;
+  }
+};
+
+/**
+ * Takes a screenshot of a web element, current frame, or viewport.
+ *
+ * The screen capture is returned as a lossless PNG image encoded as
+ * a base 64 string.
+ *
+ * If called in the content context, the |id| argument is not null and
+ * refers to a present and visible web element's ID, the capture area will
+ * be limited to the bounding box of that element.  Otherwise, the capture
+ * area will be the bounding box of the current frame.
+ *
+ * If called in the chrome context, the screenshot will always represent
+ * the entire viewport.
+ *
+ * @param {string=} id
+ *     Optional web element reference to take a screenshot of.
+ *     If undefined, a screenshot will be taken of the document element.
+ * @param {boolean=} full
+ *     True to take a screenshot of the entire document element. Is only
+ *     considered if <var>id</var> is not defined. Defaults to true.
+ * @param {boolean=} hash
+ *     True if the user requests a hash of the image data. Defaults to false.
+ * @param {boolean=} scroll
+ *     Scroll to element if |id| is provided. Defaults to true.
+ *
+ * @return {string}
+ *     If <var>hash</var> is false, PNG image encoded as Base64 encoded
+ *     string.  If <var>hash</var> is true, hex digest of the SHA-256
+ *     hash of the Base64 encoded string.
+ *
+ * @throws {NoSuchElementError}
+ *     If element represented by reference <var>id</var> is unknown.
+ * @throws {NoSuchWindowError}
+ *     Browsing context has been discarded.
+ * @throws {StaleElementReferenceError}
+ *     If element represented by reference <var>id</var> has gone stale.
+ */
+GeckoDriver.prototype.takeScreenshot = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  let { id, full, hash, scroll } = cmd.parameters;
+  let format = hash ? lazy.capture.Format.Hash : lazy.capture.Format.Base64;
+
+  full = typeof full == "undefined" ? true : full;
+  scroll = typeof scroll == "undefined" ? true : scroll;
+
+  let webEl = id ? WebReference.fromUUID(id).toJSON() : null;
+
+  // Only consider full screenshot if no element has been specified
+  full = webEl ? false : full;
+
+  return this.getActor().takeScreenshot(webEl, format, full, scroll);
+};
+
+/**
+ * Get the current browser orientation.
+ *
+ * Will return one of the valid primary orientation values
+ * portrait-primary, landscape-primary, portrait-secondary, or
+ * landscape-secondary.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.getScreenOrientation = function() {
+  lazy.assert.mobile();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+
+  const win = this.getCurrentWindow();
+
+  return win.screen.orientation.type;
+};
+
+/**
+ * Set the current browser orientation.
+ *
+ * The supplied orientation should be given as one of the valid
+ * orientation values.  If the orientation is unknown, an error will
+ * be raised.
+ *
+ * Valid orientations are "portrait" and "landscape", which fall
+ * back to "portrait-primary" and "landscape-primary" respectively,
+ * and "portrait-secondary" as well as "landscape-secondary".
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.setScreenOrientation = async function(cmd) {
+  lazy.assert.mobile();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+
+  const ors = [
+    "portrait",
+    "landscape",
+    "portrait-primary",
+    "landscape-primary",
+    "portrait-secondary",
+    "landscape-secondary",
+  ];
+
+  let or = String(cmd.parameters.orientation);
+  lazy.assert.string(or);
+  let mozOr = or.toLowerCase();
+  if (!ors.includes(mozOr)) {
+    throw new lazy.error.InvalidArgumentError(
+      `Unknown screen orientation: ${or}`
+    );
+  }
+
+  const win = this.getCurrentWindow();
+
+  try {
+    await win.screen.orientation.lock(mozOr);
+  } catch (e) {
+    throw new lazy.error.WebDriverError(
+      `Unable to set screen orientation: ${or}`
+    );
+  }
+};
+
+/**
+ * Synchronously minimizes the user agent window as if the user pressed
+ * the minimize button.
+ *
+ * No action is taken if the window is already minimized.
+ *
+ * Not supported on Fennec.
+ *
+ * @return {Object.<string, number>}
+ *     Window rect and window state.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available for current application.
+ */
+GeckoDriver.prototype.minimizeWindow = async function() {
+  lazy.assert.desktop();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  const win = this.getCurrentWindow();
+  switch (lazy.WindowState.from(win.windowState)) {
+    case lazy.WindowState.Fullscreen:
+      await exitFullscreen(win);
+      break;
+
+    case lazy.WindowState.Maximized:
+      await restoreWindow(win);
+      break;
+  }
+
+  if (lazy.WindowState.from(win.windowState) != lazy.WindowState.Minimized) {
+    let cb;
+    // Use a timed promise to abort if no window manager is present
+    await new lazy.TimedPromise(
+      resolve => {
+        cb = new lazy.DebounceCallback(resolve);
+        win.addEventListener("sizemodechange", cb);
+        win.minimize();
+      },
+      { throws: null, timeout: TIMEOUT_NO_WINDOW_MANAGER }
+    );
+    win.removeEventListener("sizemodechange", cb);
+    await new lazy.IdlePromise(win);
+  }
+
+  return this.curBrowser.rect;
+};
+
+/**
+ * Synchronously maximizes the user agent window as if the user pressed
+ * the maximize button.
+ *
+ * No action is taken if the window is already maximized.
+ *
+ * Not supported on Fennec.
+ *
+ * @return {Object.<string, number>}
+ *     Window rect.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available for current application.
+ */
+GeckoDriver.prototype.maximizeWindow = async function() {
+  lazy.assert.desktop();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  const win = this.getCurrentWindow();
+  switch (lazy.WindowState.from(win.windowState)) {
+    case lazy.WindowState.Fullscreen:
+      await exitFullscreen(win);
+      break;
+
+    case lazy.WindowState.Minimized:
+      await restoreWindow(win);
+      break;
+  }
+
+  if (lazy.WindowState.from(win.windowState) != lazy.WindowState.Maximized) {
+    let cb;
+    // Use a timed promise to abort if no window manager is present
+    await new lazy.TimedPromise(
+      resolve => {
+        cb = new lazy.DebounceCallback(resolve);
+        win.addEventListener("sizemodechange", cb);
+        win.maximize();
+      },
+      { throws: null, timeout: TIMEOUT_NO_WINDOW_MANAGER }
+    );
+    win.removeEventListener("sizemodechange", cb);
+    await new lazy.IdlePromise(win);
+  }
+
+  return this.curBrowser.rect;
+};
+
+/**
+ * Synchronously sets the user agent window to full screen as if the user
+ * had done "View > Enter Full Screen".
+ *
+ * No action is taken if the window is already in full screen mode.
+ *
+ * Not supported on Fennec.
+ *
+ * @return {Map.<string, number>}
+ *     Window rect.
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available for current application.
+ */
+GeckoDriver.prototype.fullscreenWindow = async function() {
+  lazy.assert.desktop();
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  const win = this.getCurrentWindow();
+  switch (lazy.WindowState.from(win.windowState)) {
+    case lazy.WindowState.Maximized:
+    case lazy.WindowState.Minimized:
+      await restoreWindow(win);
+      break;
+  }
+
+  if (lazy.WindowState.from(win.windowState) != lazy.WindowState.Fullscreen) {
+    let cb;
+    // Use a timed promise to abort if no window manager is present
+    await new lazy.TimedPromise(
+      resolve => {
+        cb = new lazy.DebounceCallback(resolve);
+        win.addEventListener("sizemodechange", cb);
+        win.fullScreen = true;
+      },
+      { throws: null, timeout: TIMEOUT_NO_WINDOW_MANAGER }
+    );
+    win.removeEventListener("sizemodechange", cb);
+  }
+  await new lazy.IdlePromise(win);
+
+  return this.curBrowser.rect;
+};
+
+/**
+ * Dismisses a currently displayed tab modal, or returns no such alert if
+ * no modal is displayed.
+ *
+ * @throws {NoSuchAlertError}
+ *     If there is no current user prompt.
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.dismissDialog = async function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  this._checkIfAlertIsPresent();
+
+  const dialogClosed = this.dialogObserver.dialogClosed();
+  this.dialog.dismiss();
+  await dialogClosed;
+
+  const win = this.getCurrentWindow();
+  await new lazy.IdlePromise(win);
+};
+
+/**
+ * Accepts a currently displayed tab modal, or returns no such alert if
+ * no modal is displayed.
+ *
+ * @throws {NoSuchAlertError}
+ *     If there is no current user prompt.
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.acceptDialog = async function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  this._checkIfAlertIsPresent();
+
+  const dialogClosed = this.dialogObserver.dialogClosed();
+  this.dialog.accept();
+  await dialogClosed;
+
+  const win = this.getCurrentWindow();
+  await new lazy.IdlePromise(win);
+};
+
+/**
+ * Returns the message shown in a currently displayed modal, or returns
+ * a no such alert error if no modal is currently displayed.
+ *
+ * @throws {NoSuchAlertError}
+ *     If there is no current user prompt.
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ */
+GeckoDriver.prototype.getTextFromDialog = function() {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  this._checkIfAlertIsPresent();
+  return this.dialog.text;
+};
+
+/**
+ * Set the user prompt's value field.
+ *
+ * Sends keys to the input field of a currently displayed modal, or
+ * returns a no such alert error if no modal is currently displayed. If
+ * a tab modal is currently displayed but has no means for text input,
+ * an element not visible error is returned.
+ *
+ * @param {string} text
+ *     Input to the user prompt's value field.
+ *
+ * @throws {ElementNotInteractableError}
+ *     If the current user prompt is an alert or confirm.
+ * @throws {NoSuchAlertError}
+ *     If there is no current user prompt.
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnsupportedOperationError}
+ *     If the current user prompt is something other than an alert,
+ *     confirm, or a prompt.
+ */
+GeckoDriver.prototype.sendKeysToDialog = async function(cmd) {
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  this._checkIfAlertIsPresent();
+
+  let text = lazy.assert.string(cmd.parameters.text);
+  let promptType = this.dialog.args.promptType;
+
+  switch (promptType) {
+    case "alert":
+    case "confirm":
+      throw new lazy.error.ElementNotInteractableError(
+        `User prompt of type ${promptType} is not interactable`
+      );
+    case "prompt":
+      break;
+    default:
+      await this.dismissDialog();
+      throw new lazy.error.UnsupportedOperationError(
+        `User prompt of type ${promptType} is not supported`
+      );
+  }
+  this.dialog.text = text;
+};
+
+GeckoDriver.prototype._checkIfAlertIsPresent = function() {
+  if (!this.dialog || !this.dialog.isOpen) {
+    throw new lazy.error.NoSuchAlertError();
+  }
+};
+
+GeckoDriver.prototype._handleUserPrompts = async function() {
+  if (!this.dialog || !this.dialog.isOpen) {
+    return;
+  }
+
+  let textContent = this.dialog.text;
+
+  const behavior = this.currentSession.unhandledPromptBehavior;
+  switch (behavior) {
+    case lazy.UnhandledPromptBehavior.Accept:
+      await this.acceptDialog();
+      break;
+
+    case lazy.UnhandledPromptBehavior.AcceptAndNotify:
+      await this.acceptDialog();
+      throw new lazy.error.UnexpectedAlertOpenError(
+        `Accepted user prompt dialog: ${textContent}`
+      );
+
+    case lazy.UnhandledPromptBehavior.Dismiss:
+      await this.dismissDialog();
+      break;
+
+    case lazy.UnhandledPromptBehavior.DismissAndNotify:
+      await this.dismissDialog();
+      throw new lazy.error.UnexpectedAlertOpenError(
+        `Dismissed user prompt dialog: ${textContent}`
+      );
+
+    case lazy.UnhandledPromptBehavior.Ignore:
+      throw new lazy.error.UnexpectedAlertOpenError(
+        "Encountered unhandled user prompt dialog"
+      );
+
+    default:
+      throw new TypeError(`Unknown unhandledPromptBehavior "${behavior}"`);
+  }
+};
+
+/**
+ * Enables or disables accepting new socket connections.
+ *
+ * By calling this method with `false` the server will not accept any
+ * further connections, but existing connections will not be forcible
+ * closed. Use `true` to re-enable accepting connections.
+ *
+ * Please note that when closing the connection via the client you can
+ * end-up in a non-recoverable state if it hasn't been enabled before.
+ *
+ * This method is used for custom in application shutdowns via
+ * marionette.quit() or marionette.restart(), like File -> Quit.
+ *
+ * @param {boolean} state
+ *     True if the server should accept new socket connections.
+ */
+GeckoDriver.prototype.acceptConnections = function(cmd) {
+  lazy.assert.boolean(cmd.parameters.value);
+  this._server.acceptConnections = cmd.parameters.value;
+};
+
+/**
+ * Quits the application with the provided flags.
+ *
+ * Marionette will stop accepting new connections before ending the
+ * current session, and finally attempting to quit the application.
+ *
+ * Optional {@link nsIAppStartup} flags may be provided as
+ * an array of masks, and these will be combined by ORing
+ * them with a bitmask.  The available masks are defined in
+ * https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIAppStartup.
+ *
+ * Crucially, only one of the *Quit flags can be specified. The |eRestart|
+ * flag may be bit-wise combined with one of the *Quit flags to cause
+ * the application to restart after it quits.
+ *
+ * @param {Array.<string>=} flags
+ *     Constant name of masks to pass to |Services.startup.quit|.
+ *     If empty or undefined, |nsIAppStartup.eAttemptQuit| is used.
+ *
+ * @param {boolean=} safeMode
+ *     Optional flag to indicate that the application has to
+ *     be restarted in safe mode.
+ *
+ * @return {Object<string,boolean>}
+ *     Dictionary containing information that explains the shutdown reason.
+ *     The value for `cause` contains the shutdown kind like "shutdown" or
+ *     "restart", while `forced` will indicate if it was a normal or forced
+ *     shutdown of the application. "in_app" is always set to indicate that
+ *     it is a shutdown triggered from within the application.
+ *
+ * @throws {InvalidArgumentError}
+ *     If <var>flags</var> contains unknown or incompatible flags,
+ *     for example multiple Quit flags.
+ */
+GeckoDriver.prototype.quit = async function(cmd) {
+  const { flags = [], safeMode = false } = cmd.parameters;
+  const quits = ["eConsiderQuit", "eAttemptQuit", "eForceQuit"];
+
+  lazy.assert.array(flags, `Expected "flags" to be an array`);
+  lazy.assert.boolean(safeMode, `Expected "safeMode" to be a boolean`);
+
+  if (safeMode && !flags.includes("eRestart")) {
+    throw new lazy.error.InvalidArgumentError(
+      `"safeMode" only works with restart flag`
+    );
+  }
+
+  if (flags.includes("eSilently")) {
+    if (!this.currentSession.capabilities.get("moz:windowless")) {
+      throw new lazy.error.UnsupportedOperationError(
+        `Silent restarts only allowed with "moz:windowless" capability set`
+      );
+    }
+    if (!flags.includes("eRestart")) {
+      throw new lazy.error.InvalidArgumentError(
+        `"silently" only works with restart flag`
+      );
+    }
+  }
+
+  let quitSeen;
+  let mode = 0;
+  if (flags.length) {
+    for (let k of flags) {
+      lazy.assert.in(k, Ci.nsIAppStartup);
+
+      if (quits.includes(k)) {
+        if (quitSeen) {
+          throw new lazy.error.InvalidArgumentError(
+            `${k} cannot be combined with ${quitSeen}`
+          );
+        }
+        quitSeen = k;
+      }
+
+      mode |= Ci.nsIAppStartup[k];
+    }
+  }
+
+  if (!quitSeen) {
+    mode |= Ci.nsIAppStartup.eAttemptQuit;
+  }
+
+  this._server.acceptConnections = false;
+  this.deleteSession();
+
+  // Notify all windows that an application quit has been requested.
+  const cancelQuit = Cc["@mozilla.org/supports-PRBool;1"].createInstance(
+    Ci.nsISupportsPRBool
+  );
+  Services.obs.notifyObservers(cancelQuit, "quit-application-requested");
+
+  // If the shutdown of the application is prevented force quit it instead.
+  if (cancelQuit.data) {
+    mode |= Ci.nsIAppStartup.eForceQuit;
+  }
+
+  // delay response until the application is about to quit
+  let quitApplication = lazy.waitForObserverTopic("quit-application");
+
+  if (safeMode) {
+    Services.startup.restartInSafeMode(mode);
+  } else {
+    Services.startup.quit(mode);
+  }
+
+  return {
+    cause: (await quitApplication).data,
+    forced: cancelQuit.data,
+    in_app: true,
+  };
+};
+
+GeckoDriver.prototype.installAddon = function(cmd) {
+  lazy.assert.desktop();
+
+  let path = cmd.parameters.path;
+  let temp = cmd.parameters.temporary || false;
+  if (
+    typeof path == "undefined" ||
+    typeof path != "string" ||
+    typeof temp != "boolean"
+  ) {
+    throw new lazy.error.InvalidArgumentError();
+  }
+
+  return lazy.Addon.install(path, temp);
+};
+
+GeckoDriver.prototype.uninstallAddon = function(cmd) {
+  lazy.assert.desktop();
+
+  let id = cmd.parameters.id;
+  if (typeof id == "undefined" || typeof id != "string") {
+    throw new lazy.error.InvalidArgumentError();
+  }
+
+  return lazy.Addon.uninstall(id);
+};
+
+/**
+ * Retrieve the localized string for the specified entity id.
+ *
+ * Example:
+ *     localizeEntity(["chrome://branding/locale/brand.dtd"], "brandShortName")
+ *
+ * @param {Array.<string>} urls
+ *     Array of .dtd URLs.
+ * @param {string} id
+ *     The ID of the entity to retrieve the localized string for.
+ *
+ * @return {string}
+ *     The localized string for the requested entity.
+ */
+GeckoDriver.prototype.localizeEntity = function(cmd) {
+  let { urls, id } = cmd.parameters;
+
+  if (!Array.isArray(urls)) {
+    throw new lazy.error.InvalidArgumentError(
+      "Value of `urls` should be of type 'Array'"
+    );
+  }
+  if (typeof id != "string") {
+    throw new lazy.error.InvalidArgumentError(
+      "Value of `id` should be of type 'string'"
+    );
+  }
+
+  return lazy.l10n.localizeEntity(urls, id);
+};
+
+/**
+ * Retrieve the localized string for the specified property id.
+ *
+ * Example:
+ *
+ *     localizeProperty(
+ *         ["chrome://global/locale/findbar.properties"], "FastFind");
+ *
+ * @param {Array.<string>} urls
+ *     Array of .properties URLs.
+ * @param {string} id
+ *     The ID of the property to retrieve the localized string for.
+ *
+ * @return {string}
+ *     The localized string for the requested property.
+ */
+GeckoDriver.prototype.localizeProperty = function(cmd) {
+  let { urls, id } = cmd.parameters;
+
+  if (!Array.isArray(urls)) {
+    throw new lazy.error.InvalidArgumentError(
+      "Value of `urls` should be of type 'Array'"
+    );
+  }
+  if (typeof id != "string") {
+    throw new lazy.error.InvalidArgumentError(
+      "Value of `id` should be of type 'string'"
+    );
+  }
+
+  return lazy.l10n.localizeProperty(urls, id);
+};
+
+/**
+ * Initialize the reftest mode
+ */
+GeckoDriver.prototype.setupReftest = async function(cmd) {
+  if (this._reftest) {
+    throw new lazy.error.UnsupportedOperationError(
+      "Called reftest:setup with a reftest session already active"
+    );
+  }
+
+  let {
+    urlCount = {},
+    screenshot = "unexpected",
+    isPrint = false,
+  } = cmd.parameters;
+  if (!["always", "fail", "unexpected"].includes(screenshot)) {
+    throw new lazy.error.InvalidArgumentError(
+      "Value of `screenshot` should be 'always', 'fail' or 'unexpected'"
+    );
+  }
+
+  this._reftest = new lazy.reftest.Runner(this);
+  this._reftest.setup(urlCount, screenshot, isPrint);
+};
+
+/** Run a reftest. */
+GeckoDriver.prototype.runReftest = async function(cmd) {
+  let {
+    test,
+    references,
+    expected,
+    timeout,
+    width,
+    height,
+    pageRanges,
+  } = cmd.parameters;
+
+  if (!this._reftest) {
+    throw new lazy.error.UnsupportedOperationError(
+      "Called reftest:run before reftest:start"
+    );
+  }
+
+  lazy.assert.string(test);
+  lazy.assert.string(expected);
+  lazy.assert.array(references);
+
+  return {
+    value: await this._reftest.run(
+      test,
+      references,
+      expected,
+      timeout,
+      pageRanges,
+      width,
+      height
+    ),
+  };
+};
+
+/**
+ * End a reftest run.
+ *
+ * Closes the reftest window (without changing the current window handle),
+ * and removes cached canvases.
+ */
+GeckoDriver.prototype.teardownReftest = function() {
+  if (!this._reftest) {
+    throw new lazy.error.UnsupportedOperationError(
+      "Called reftest:teardown before reftest:start"
+    );
+  }
+
+  this._reftest.teardown();
+  this._reftest = null;
+};
+
+/**
+ * Print page as PDF.
+ *
+ * @param {boolean=} landscape
+ *     Paper orientation. Defaults to false.
+ * @param {number=} margin.bottom
+ *     Bottom margin in cm. Defaults to 1cm (~0.4 inches).
+ * @param {number=} margin.left
+ *     Left margin in cm. Defaults to 1cm (~0.4 inches).
+ * @param {number=} margin.right
+ *     Right margin in cm. Defaults to 1cm (~0.4 inches).
+ * @param {number=} margin.top
+ *     Top margin in cm. Defaults to 1cm (~0.4 inches).
+ * @param {Array.<string|number>=} pageRanges
+ *     Paper ranges to print, e.g., ['1-5', 8, '11-13'].
+ *     Defaults to the empty array, which means print all pages.
+ * @param {number=} page.height
+ *     Paper height in cm. Defaults to US letter height (11 inches / 27.94cm)
+ * @param {number=} page.width
+ *     Paper width in cm. Defaults to US letter width (8.5 inches / 21.59cm)
+ * @param {boolean=} shrinkToFit
+ *     Whether or not to override page size as defined by CSS.
+ *     Defaults to true, in which case the content will be scaled
+ *     to fit the paper size.
+ * @param {boolean=} printBackground
+ *     Print background graphics. Defaults to false.
+ * @param {number=} scale
+ *     Scale of the webpage rendering. Defaults to 1.
+ *
+ * @return {string}
+ *     Base64 encoded PDF representing printed document
+ *
+ * @throws {NoSuchWindowError}
+ *     Top-level browsing context has been discarded.
+ * @throws {UnexpectedAlertOpenError}
+ *     A modal dialog is open, blocking this operation.
+ * @throws {UnsupportedOperationError}
+ *     Not available in chrome context.
+ */
+GeckoDriver.prototype.print = async function(cmd) {
+  lazy.assert.content(this.context);
+  lazy.assert.open(this.getBrowsingContext({ top: true }));
+  await this._handleUserPrompts();
+
+  const settings = lazy.print.addDefaultSettings(cmd.parameters);
+  for (let prop of ["top", "bottom", "left", "right"]) {
+    lazy.assert.positiveNumber(
+      settings.margin[prop],
+      lazy.pprint`margin.${prop} is not a positive number`
+    );
+  }
+  for (let prop of ["width", "height"]) {
+    lazy.assert.positiveNumber(
+      settings.page[prop],
+      lazy.pprint`page.${prop} is not a positive number`
+    );
+  }
+  lazy.assert.positiveNumber(
+    settings.scale,
+    `scale ${settings.scale} is not a positive number`
+  );
+  lazy.assert.that(
+    s =>
+      s >= lazy.print.minScaleValue &&
+      settings.scale <= lazy.print.maxScaleValue,
+    `scale ${settings.scale} is outside the range ${lazy.print.minScaleValue}-${lazy.print.maxScaleValue}`
+  )(settings.scale);
+  lazy.assert.boolean(settings.shrinkToFit);
+  lazy.assert.boolean(settings.landscape);
+  lazy.assert.boolean(settings.printBackground);
+  lazy.assert.array(settings.pageRanges);
+
+  const linkedBrowser = this.curBrowser.tab.linkedBrowser;
+  const filePath = await lazy.print.printToFile(linkedBrowser, settings);
+
+  // return all data as a base64 encoded string
+  let bytes;
+  try {
+    bytes = await IOUtils.read(filePath);
+  } finally {
+    await IOUtils.remove(filePath);
+  }
+
+  // Each UCS2 character has an upper byte of 0 and a lower byte matching
+  // the binary data. Splitting the file into chunks to avoid hitting the
+  // internal argument length limit.
+  const chunks = [];
+  // This is the largest power of 2 smaller than MAX_ARGS_LENGTH defined in Spidermonkey
+  const argLengthLimit = 262144;
+
+  for (let offset = 0; offset < bytes.length; offset += argLengthLimit) {
+    const chunkData = bytes.subarray(offset, offset + argLengthLimit);
+
+    chunks.push(String.fromCharCode.apply(null, chunkData));
+  }
+
+  return {
+    value: btoa(chunks.join("")),
+  };
+};
+
+GeckoDriver.prototype.setPermission = async function(cmd) {
+  const { descriptor, state, oneRealm = false } = cmd.parameters;
+
+  lazy.assert.boolean(oneRealm);
+  lazy.assert.that(
+    state => ["granted", "denied", "prompt"].includes(state),
+    `state is ${state}, expected "granted", "denied", or "prompt"`
+  )(state);
+
+  lazy.permissions.set(descriptor, state, oneRealm);
+};
+
+GeckoDriver.prototype.commands = {
+  // Marionette service
+  "Marionette:AcceptConnections": GeckoDriver.prototype.acceptConnections,
+  "Marionette:GetContext": GeckoDriver.prototype.getContext,
+  "Marionette:GetScreenOrientation": GeckoDriver.prototype.getScreenOrientation,
+  "Marionette:GetWindowType": GeckoDriver.prototype.getWindowType,
+  "Marionette:Quit": GeckoDriver.prototype.quit,
+  "Marionette:SetContext": GeckoDriver.prototype.setContext,
+  "Marionette:SetScreenOrientation": GeckoDriver.prototype.setScreenOrientation,
+  "Marionette:SingleTap": GeckoDriver.prototype.singleTap,
+
+  // Addon service
+  "Addon:Install": GeckoDriver.prototype.installAddon,
+  "Addon:Uninstall": GeckoDriver.prototype.uninstallAddon,
+
+  // L10n service
+  "L10n:LocalizeEntity": GeckoDriver.prototype.localizeEntity,
+  "L10n:LocalizeProperty": GeckoDriver.prototype.localizeProperty,
+
+  // Reftest service
+  "reftest:setup": GeckoDriver.prototype.setupReftest,
+  "reftest:run": GeckoDriver.prototype.runReftest,
+  "reftest:teardown": GeckoDriver.prototype.teardownReftest,
+
+  // WebDriver service
+  "WebDriver:AcceptAlert": GeckoDriver.prototype.acceptDialog,
+  // deprecated, no longer used since the geckodriver 0.30.0 release
+  "WebDriver:AcceptDialog": GeckoDriver.prototype.acceptDialog,
+  "WebDriver:AddCookie": GeckoDriver.prototype.addCookie,
+  "WebDriver:Back": GeckoDriver.prototype.goBack,
+  "WebDriver:CloseChromeWindow": GeckoDriver.prototype.closeChromeWindow,
+  "WebDriver:CloseWindow": GeckoDriver.prototype.close,
+  "WebDriver:DeleteAllCookies": GeckoDriver.prototype.deleteAllCookies,
+  "WebDriver:DeleteCookie": GeckoDriver.prototype.deleteCookie,
+  "WebDriver:DeleteSession": GeckoDriver.prototype.deleteSession,
+  "WebDriver:DismissAlert": GeckoDriver.prototype.dismissDialog,
+  "WebDriver:ElementClear": GeckoDriver.prototype.clearElement,
+  "WebDriver:ElementClick": GeckoDriver.prototype.clickElement,
+  "WebDriver:ElementSendKeys": GeckoDriver.prototype.sendKeysToElement,
+  "WebDriver:ExecuteAsyncScript": GeckoDriver.prototype.executeAsyncScript,
+  "WebDriver:ExecuteScript": GeckoDriver.prototype.executeScript,
+  "WebDriver:FindElement": GeckoDriver.prototype.findElement,
+  "WebDriver:FindElements": GeckoDriver.prototype.findElements,
+  "WebDriver:Forward": GeckoDriver.prototype.goForward,
+  "WebDriver:FullscreenWindow": GeckoDriver.prototype.fullscreenWindow,
+  "WebDriver:GetActiveElement": GeckoDriver.prototype.getActiveElement,
+  "WebDriver:GetAlertText": GeckoDriver.prototype.getTextFromDialog,
+  "WebDriver:GetCapabilities": GeckoDriver.prototype.getSessionCapabilities,
+  "WebDriver:GetCookies": GeckoDriver.prototype.getCookies,
+  "WebDriver:GetCurrentURL": GeckoDriver.prototype.getCurrentUrl,
+  "WebDriver:GetElementAttribute": GeckoDriver.prototype.getElementAttribute,
+  "WebDriver:GetElementCSSValue":
+    GeckoDriver.prototype.getElementValueOfCssProperty,
+  "WebDriver:GetElementProperty": GeckoDriver.prototype.getElementProperty,
+  "WebDriver:GetElementRect": GeckoDriver.prototype.getElementRect,
+  "WebDriver:GetElementTagName": GeckoDriver.prototype.getElementTagName,
+  "WebDriver:GetElementText": GeckoDriver.prototype.getElementText,
+  "WebDriver:GetPageSource": GeckoDriver.prototype.getPageSource,
+  "WebDriver:GetShadowRoot": GeckoDriver.prototype.getShadowRoot,
+  "WebDriver:GetTimeouts": GeckoDriver.prototype.getTimeouts,
+  "WebDriver:GetTitle": GeckoDriver.prototype.getTitle,
+  "WebDriver:GetWindowHandle": GeckoDriver.prototype.getWindowHandle,
+  "WebDriver:GetWindowHandles": GeckoDriver.prototype.getWindowHandles,
+  "WebDriver:GetWindowRect": GeckoDriver.prototype.getWindowRect,
+  "WebDriver:IsElementDisplayed": GeckoDriver.prototype.isElementDisplayed,
+  "WebDriver:IsElementEnabled": GeckoDriver.prototype.isElementEnabled,
+  "WebDriver:IsElementSelected": GeckoDriver.prototype.isElementSelected,
+  "WebDriver:MinimizeWindow": GeckoDriver.prototype.minimizeWindow,
+  "WebDriver:MaximizeWindow": GeckoDriver.prototype.maximizeWindow,
+  "WebDriver:Navigate": GeckoDriver.prototype.navigateTo,
+  "WebDriver:NewSession": GeckoDriver.prototype.newSession,
+  "WebDriver:NewWindow": GeckoDriver.prototype.newWindow,
+  "WebDriver:PerformActions": GeckoDriver.prototype.performActions,
+  "WebDriver:Print": GeckoDriver.prototype.print,
+  "WebDriver:Refresh": GeckoDriver.prototype.refresh,
+  "WebDriver:ReleaseActions": GeckoDriver.prototype.releaseActions,
+  "WebDriver:SendAlertText": GeckoDriver.prototype.sendKeysToDialog,
+  "WebDriver:SetPermission": GeckoDriver.prototype.setPermission,
+  "WebDriver:SetTimeouts": GeckoDriver.prototype.setTimeouts,
+  "WebDriver:SetWindowRect": GeckoDriver.prototype.setWindowRect,
+  "WebDriver:SwitchToFrame": GeckoDriver.prototype.switchToFrame,
+  "WebDriver:SwitchToParentFrame": GeckoDriver.prototype.switchToParentFrame,
+  "WebDriver:SwitchToWindow": GeckoDriver.prototype.switchToWindow,
+  "WebDriver:TakeScreenshot": GeckoDriver.prototype.takeScreenshot,
+};
+
+async function exitFullscreen(win) {
+  let cb;
+  // Use a timed promise to abort if no window manager is present
+  await new lazy.TimedPromise(
+    resolve => {
+      cb = new lazy.DebounceCallback(resolve);
+      win.addEventListener("sizemodechange", cb);
+      win.fullScreen = false;
+    },
+    { throws: null, timeout: TIMEOUT_NO_WINDOW_MANAGER }
+  );
+  win.removeEventListener("sizemodechange", cb);
+  await new lazy.IdlePromise(win);
+}
+
+async function restoreWindow(win) {
+  let cb;
+  if (lazy.WindowState.from(win.windowState) == lazy.WindowState.Normal) {
+    return;
+  }
+  // Use a timed promise to abort if no window manager is present
+  await new lazy.TimedPromise(
+    resolve => {
+      cb = new lazy.DebounceCallback(resolve);
+      win.addEventListener("sizemodechange", cb);
+      win.restore();
+    },
+    { throws: null, timeout: TIMEOUT_NO_WINDOW_MANAGER }
+  );
+  win.removeEventListener("sizemodechange", cb);
+  await new lazy.IdlePromise(win);
+}