Adding upstream version 110.0.1.upstream/110.0.1upstream

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

14 files changed, 3131 insertions, 0 deletions

diff --git a/toolkit/components/prompts/test/.eslintrc.js b/toolkit/components/prompts/test/.eslintrc.js
new file mode 100644
index 0000000000..af973e82fe
--- /dev/null
+++ b/toolkit/components/prompts/test/.eslintrc.js
@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = {
+  rules: {
+    // ownerGlobal doesn't exist in content privileged windows.
+    "mozilla/use-ownerGlobal": "off",
+  },
+};
diff --git a/toolkit/components/prompts/test/PromptTestUtils.jsm b/toolkit/components/prompts/test/PromptTestUtils.jsm
new file mode 100644
index 0000000000..53c9da01cd
--- /dev/null
+++ b/toolkit/components/prompts/test/PromptTestUtils.jsm
@@ -0,0 +1,248 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/*
+ * Utility module for tests to interact with prompts spawned by nsIPrompt or
+ * nsIPromptService.
+ */
+
+"use strict";
+
+const { XPCOMUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/XPCOMUtils.sys.mjs"
+);
+const { BrowserTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/BrowserTestUtils.sys.mjs"
+);
+
+const { TestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TestUtils.sys.mjs"
+);
+
+const EXPORTED_SYMBOLS = ["PromptTestUtils"];
+
+const kPrefs = {};
+
+// Whether prompts with modal type TAB are shown as SubDialog (true) or
+// TabModalPrompt (false).
+XPCOMUtils.defineLazyPreferenceGetter(
+  kPrefs,
+  "tabPromptSubDialogEnabled",
+  "prompts.tabChromePromptSubDialog",
+  false
+);
+
+// Whether web content prompts (alert etc.) are shown as SubDialog (true)
+// or TabModalPrompt (false)
+XPCOMUtils.defineLazyPreferenceGetter(
+  kPrefs,
+  "contentPromptSubDialogEnabled",
+  "prompts.contentPromptSubDialog",
+  false
+);
+
+function isCommonDialog(modalType) {
+  return (
+    modalType === Services.prompt.MODAL_TYPE_WINDOW ||
+    (kPrefs.tabPromptSubDialogEnabled &&
+      modalType === Services.prompt.MODAL_TYPE_TAB) ||
+    (kPrefs.contentPromptSubDialogEnabled &&
+      modalType === Services.prompt.MODAL_TYPE_CONTENT)
+  );
+}
+
+let PromptTestUtils = {
+  /**
+   * Wait for a prompt from nsIPrompt or nsIPromptsService, interact with it and
+   * click the specified button to close it.
+   * @param {Browser|Window} [parent] - Parent of the prompt. This can be
+   * either the parent window or the browser. For tab prompts, if given a
+   * window, the currently selected browser in that window will be used.
+   * @param {Object} promptOptions - @see waitForPrompt
+   * @param {Object} promptActions - @see handlePrompt
+   * @returns {Promise} - A promise which resolves once the prompt has been
+   * closed.
+   */
+  async handleNextPrompt(parent, promptOptions, promptActions) {
+    let dialog = await this.waitForPrompt(parent, promptOptions);
+    return this.handlePrompt(dialog, promptActions);
+  },
+
+  /**
+   * Interact with an existing prompt and close it.
+   * @param {Dialog} dialog - The dialog instance associated with the prompt.
+   * @param {Object} [actions] - Options on how to interact with the
+   * prompt and how to close it.
+   * @param {Boolean} [actions.checkboxState] - Set the checkbox state.
+   * true = checked, false = unchecked.
+   * @param {Number} [actions.buttonNumClick] - Which button to click to close
+   * the prompt.
+   * @param {String} [actions.loginInput] - Input text for the login text field.
+   * This field is also used for text input for the "prompt" type.
+   * @param {String} [actions.passwordInput] - Input text for the password text
+   * field.
+   * @returns {Promise} - A promise which resolves once the prompt has been
+   * closed.
+   */
+  handlePrompt(
+    dialog,
+    {
+      checkboxState = null,
+      buttonNumClick = 0,
+      loginInput = null,
+      passwordInput = null,
+    } = {}
+  ) {
+    let promptClosePromise;
+
+    // Get parent window to listen for prompt close event
+    let win;
+    if (isCommonDialog(dialog.args.modalType)) {
+      win = dialog.ui.prompt?.opener;
+    } else {
+      // Tab prompts should always have a parent window
+      win = dialog.ui.prompt.win;
+    }
+
+    if (win) {
+      promptClosePromise = BrowserTestUtils.waitForEvent(
+        win,
+        "DOMModalDialogClosed"
+      );
+    } else {
+      // We don't have a parent, wait for window close instead
+      promptClosePromise = BrowserTestUtils.windowClosed(dialog.ui.prompt);
+    }
+
+    if (typeof checkboxState == "boolean") {
+      dialog.ui.checkbox.checked = checkboxState;
+    }
+
+    if (loginInput != null) {
+      dialog.ui.loginTextbox.value = loginInput;
+    }
+
+    if (passwordInput != null) {
+      dialog.ui.password1Textbox.value = passwordInput;
+    }
+
+    let button = dialog.ui["button" + buttonNumClick];
+    if (!button) {
+      throw new Error("Could not find button with index " + buttonNumClick);
+    }
+    button.click();
+
+    return promptClosePromise;
+  },
+
+  /**
+   * Wait for a prompt from nsIPrompt or nsIPromptsService to open.
+   * @param {Browser|Window} [parent] - Parent of the prompt. This can be either
+   * the parent window or the browser. For tab prompts, if given a window, the
+   * currently selected browser in that window will be used.
+   * If not given a parent, the method will return on prompts of any window.
+   * @param {Object} attrs - The prompt attributes to filter for.
+   * @param {Number} attrs.modalType - Whether the expected prompt is a content, tab or window prompt.
+   * nsIPromptService.<MODAL_TYPE_WINDOW|MODAL_TYPE_TAB|MODAL_TYPE_CONTENT>
+   * @param {String} [attrs.promptType] - Common dialog type of the prompt to filter for.
+   *  @see {@link CommonDialog} for possible prompt types.
+   * @returns {Promise<CommonDialog>} - A Promise which resolves with a dialog
+   * object once the prompt has loaded.
+   */
+  async waitForPrompt(parent, { modalType, promptType = null } = {}) {
+    if (!modalType) {
+      throw new Error("modalType is mandatory");
+    }
+
+    // Get window by browser or browser by window, depending on what is passed
+    // via the parent arg. If the caller passes parent=null, both will be null.
+    let parentWindow;
+    let parentBrowser;
+    if (parent) {
+      if (Element.isInstance(parent)) {
+        // Parent is browser
+        parentBrowser = parent;
+        parentWindow = parentBrowser.ownerGlobal;
+      } else if (parent instanceof Ci.nsIDOMChromeWindow) {
+        // Parent is window
+        parentWindow = parent;
+        parentBrowser = parentWindow.gBrowser?.selectedBrowser;
+      } else {
+        throw new Error("Invalid parent. Expected browser or dom window");
+      }
+    }
+
+    let topic = isCommonDialog(modalType)
+      ? "common-dialog-loaded"
+      : "tabmodal-dialog-loaded";
+
+    let dialog;
+    await TestUtils.topicObserved(topic, subject => {
+      // If we are not given a browser, use the currently selected browser of the window
+      let browser =
+        parentBrowser || subject.ownerGlobal.gBrowser?.selectedBrowser;
+      if (isCommonDialog(modalType)) {
+        // Is not associated with given parent window, skip
+        if (parentWindow && subject.opener !== parentWindow) {
+          return false;
+        }
+
+        // For tab prompts, ensure that the associated browser matches.
+        if (browser && modalType == Services.prompt.MODAL_TYPE_TAB) {
+          let dialogBox = parentWindow.gBrowser.getTabDialogBox(browser);
+          let hasMatchingDialog = dialogBox
+            .getTabDialogManager()
+            ._dialogs.some(
+              d => d._frame?.browsingContext == subject.browsingContext
+            );
+          if (!hasMatchingDialog) {
+            return false;
+          }
+        }
+
+        if (browser && modalType == Services.prompt.MODAL_TYPE_CONTENT) {
+          let dialogBox = parentWindow.gBrowser.getTabDialogBox(browser);
+          let hasMatchingDialog = dialogBox
+            .getContentDialogManager()
+            ._dialogs.some(
+              d => d._frame?.browsingContext == subject.browsingContext
+            );
+          if (!hasMatchingDialog) {
+            return false;
+          }
+        }
+
+        // subject is the window object of the prompt which has a Dialog object
+        // attached.
+        dialog = subject.Dialog;
+      } else {
+        // subject is the tabprompt dom node
+        // Get the full prompt object which has the dialog object
+        let prompt = browser.tabModalPromptBox.getPrompt(subject);
+
+        // Is not associated with given parent browser, skip.
+        if (!prompt) {
+          return false;
+        }
+
+        dialog = prompt.Dialog;
+      }
+
+      // Not the modalType we're looking for.
+      // For window prompts dialog.args.modalType is undefined.
+      if (isCommonDialog(modalType) && dialog.args.modalType !== modalType) {
+        return false;
+      }
+
+      // Not the promptType we're looking for.
+      if (promptType && dialog.args.promptType !== promptType) {
+        return false;
+      }
+
+      // Prompt found
+      return true;
+    });
+
+    return dialog;
+  },
+};
diff --git a/toolkit/components/prompts/test/bug619644_inner.html b/toolkit/components/prompts/test/bug619644_inner.html
new file mode 100644
index 0000000000..cecfa78bad
--- /dev/null
+++ b/toolkit/components/prompts/test/bug619644_inner.html
@@ -0,0 +1,7 @@
+<head></head><body><p>Original content</p>
+<script>
+    window.opener.postMessage("", "*");
+    confirm("Message");
+    document.write("Extra content");
+    window.opener.postMessage(document.documentElement.innerHTML, "*");
+</script></body>
diff --git a/toolkit/components/prompts/test/bug625187_iframe.html b/toolkit/components/prompts/test/bug625187_iframe.html
new file mode 100644
index 0000000000..740d59a617
--- /dev/null
+++ b/toolkit/components/prompts/test/bug625187_iframe.html
@@ -0,0 +1,16 @@
+<html>
+<head>
+  <title>Test for Bug 625187 - the iframe</title>
+<!--
+   - Any copyright is dedicated to the Public Domain.
+   - http://creativecommons.org/publicdomain/zero/1.0/
+   -
+   - Contributor(s):
+   -   Mihai Sucan <mihai.sucan@gmail.com>
+   -->
+</head>
+<body>
+<p><button id="btn1" onclick="alert('hello world 2')">Button 2</button></p>
+<p><button id="btn2" onclick="window.parent.alert('hello world 3')">Button 3</button></p>
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/chrome.ini b/toolkit/components/prompts/test/chrome.ini
new file mode 100644
index 0000000000..90eee3a761
--- /dev/null
+++ b/toolkit/components/prompts/test/chrome.ini
@@ -0,0 +1,11 @@
+[DEFAULT]
+support-files =
+  prompt_common.js
+  chromeScript.js
+
+[test_modal_prompts.html]
+skip-if =
+  toolkit == 'android' #android: TIMED_OUT
+  os == 'linux' && (debug || asan || tsan)
+[test_modal_select.html]
+skip-if = toolkit == 'android' #android: TIMED_OUT
diff --git a/toolkit/components/prompts/test/chromeScript.js b/toolkit/components/prompts/test/chromeScript.js
new file mode 100644
index 0000000000..e31fbdc851
--- /dev/null
+++ b/toolkit/components/prompts/test/chromeScript.js
@@ -0,0 +1,354 @@
+/* eslint-env mozilla/chrome-script */
+
+const { clearInterval, setInterval, setTimeout } = ChromeUtils.importESModule(
+  "resource://gre/modules/Timer.sys.mjs"
+);
+
+const { BrowserTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/BrowserTestUtils.sys.mjs"
+);
+
+var tabSubDialogsEnabled = Services.prefs.getBoolPref(
+  "prompts.tabChromePromptSubDialog",
+  false
+);
+
+var contentPromptSubdialogsEnabled = Services.prefs.getBoolPref(
+  "prompts.contentPromptSubDialog",
+  false
+);
+
+// Define these to make EventUtils happy.
+let window = this;
+let parent = {};
+
+let EventUtils = {};
+Services.scriptloader.loadSubScript(
+  "chrome://mochikit/content/tests/SimpleTest/EventUtils.js",
+  EventUtils
+);
+
+addMessageListener("handlePrompt", msg => {
+  info("Received handlePrompt message");
+  handlePromptWhenItAppears(msg.action, msg.modalType, msg.isSelect);
+});
+
+async function handlePromptWhenItAppears(action, modalType, isSelect) {
+  try {
+    if (!(await handlePrompt(action, modalType, isSelect))) {
+      setTimeout(
+        () => this.handlePromptWhenItAppears(action, modalType, isSelect),
+        100
+      );
+    }
+  } catch (e) {
+    info(`handlePromptWhenItAppears: exception: ${e}`);
+  }
+}
+
+function checkTabModal(prompt, browser) {
+  let doc = browser.ownerDocument;
+
+  let { bottom: toolboxBottom } = doc
+    .getElementById("navigator-toolbox")
+    .getBoundingClientRect();
+
+  let { mainContainer } = prompt.ui;
+
+  let { x, y } = mainContainer.getBoundingClientRect();
+  ok(y > 0, "Container should have y > 0");
+  // Inset by 1px since the corner point doesn't return the frame due to the
+  // border-radius.
+  is(
+    doc.elementFromPoint(x + 1, y + 1).parentNode,
+    mainContainer,
+    "Check tabmodalprompt is visible"
+  );
+
+  info("Click to the left of the dialog over the content area");
+  isnot(
+    doc.elementFromPoint(x - 10, y + 50),
+    browser,
+    "Check clicks on the content area don't go to the browser"
+  );
+  is(
+    doc.elementFromPoint(x - 10, y + 50),
+    prompt.element,
+    "Check clicks on the content area go to the prompt dialog background"
+  );
+
+  if (prompt.args.modalType == Ci.nsIPrompt.MODAL_TYPE_TAB) {
+    ok(
+      y <= toolboxBottom - 5,
+      "Dialog should overlap the toolbox by at least 5px"
+    );
+  } else {
+    ok(y >= toolboxBottom, "Dialog must not overlap with toolbox.");
+  }
+
+  ok(
+    browser.hasAttribute("tabmodalPromptShowing"),
+    "Check browser has @tabmodalPromptShowing"
+  );
+}
+
+async function handlePrompt(action, modalType, isSelect) {
+  info(`handlePrompt: modalType=${modalType}`);
+
+  let ui;
+  let browserWin = Services.wm.getMostRecentWindow("navigator:browser");
+
+  if (
+    (!contentPromptSubdialogsEnabled &&
+      modalType === Services.prompt.MODAL_TYPE_CONTENT) ||
+    (!tabSubDialogsEnabled && modalType === Services.prompt.MODAL_TYPE_TAB)
+  ) {
+    let gBrowser = browserWin.gBrowser;
+    let promptManager = gBrowser.getTabModalPromptBox(gBrowser.selectedBrowser);
+    let prompts = promptManager.listPrompts();
+    if (!prompts.length) {
+      info("handlePrompt: no prompt found. retrying...");
+      return false; // try again in a bit
+    }
+
+    ui = prompts[0].Dialog.ui;
+    checkTabModal(prompts[0], gBrowser.selectedBrowser);
+  } else {
+    let doc = getDialogDoc();
+    if (!doc) {
+      info("handlePrompt: no document found. retrying...");
+      return false; // try again in a bit
+    }
+
+    if (isSelect) {
+      ui = doc;
+    } else {
+      ui = doc.defaultView.Dialog.ui;
+    }
+  }
+
+  let dialogClosed = BrowserTestUtils.waitForEvent(
+    browserWin,
+    "DOMModalDialogClosed"
+  );
+
+  let promptState;
+  if (isSelect) {
+    promptState = getSelectState(ui);
+    dismissSelect(ui, action);
+  } else {
+    promptState = getPromptState(ui);
+    dismissPrompt(ui, action);
+  }
+
+  // Wait until the prompt has been closed before sending callback msg.
+  // Unless the test explicitly doesn't request a button click.
+  if (action.buttonClick !== "none") {
+    info(`handlePrompt: wait for dialogClosed`);
+    await dialogClosed;
+  }
+
+  info(`handlePrompt: send promptHandled`);
+  sendAsyncMessage("promptHandled", { promptState });
+  return true;
+}
+
+function getSelectState(ui) {
+  let listbox = ui.getElementById("list");
+
+  let state = {};
+  state.msg = ui.getElementById("info.txt").value;
+  state.selectedIndex = listbox.selectedIndex;
+  state.items = [];
+
+  for (let i = 0; i < listbox.itemCount; i++) {
+    let item = listbox.getItemAtIndex(i).label;
+    state.items.push(item);
+  }
+
+  return state;
+}
+
+function getPromptState(ui) {
+  let state = {};
+  state.msg = ui.infoBody.textContent;
+  state.infoRowHidden = ui.infoRow?.hidden || false;
+  state.titleHidden = ui.infoTitle.hidden;
+  state.textHidden = ui.loginContainer.hidden;
+  state.passHidden = ui.password1Container.hidden;
+  state.checkHidden = ui.checkboxContainer.hidden;
+  state.checkMsg = state.checkHidden ? "" : ui.checkbox.label;
+  state.checked = state.checkHidden ? false : ui.checkbox.checked;
+  // TabModalPrompts don't have an infoIcon
+  state.iconClass = ui.infoIcon ? ui.infoIcon.className : null;
+  state.textValue = ui.loginTextbox.value;
+  state.passValue = ui.password1Textbox.value;
+
+  state.butt0Label = ui.button0.label;
+  state.butt1Label = ui.button1.label;
+  state.butt2Label = ui.button2.label;
+
+  state.butt0Disabled = ui.button0.disabled;
+  state.butt1Disabled = ui.button1.disabled;
+  state.butt2Disabled = ui.button2.disabled;
+
+  function isDefaultButton(b) {
+    return b.hasAttribute("default") && b.getAttribute("default") == "true";
+  }
+  state.defButton0 = isDefaultButton(ui.button0);
+  state.defButton1 = isDefaultButton(ui.button1);
+  state.defButton2 = isDefaultButton(ui.button2);
+
+  let e = Services.focus.focusedElement;
+
+  if (e == null) {
+    state.focused = null;
+  } else if (ui.button0.isSameNode(e)) {
+    state.focused = "button0";
+  } else if (ui.button1.isSameNode(e)) {
+    state.focused = "button1";
+  } else if (ui.button2.isSameNode(e)) {
+    state.focused = "button2";
+  } else if (e.isSameNode(ui.loginTextbox)) {
+    state.focused = "textField";
+  } else if (e.isSameNode(ui.password1Textbox)) {
+    state.focused = "passField";
+  } else if (ui.infoBody.isSameNode(e)) {
+    state.focused = "infoBody";
+  } else {
+    state.focused =
+      "ERROR: unexpected element focused: " + (e ? e.localName : "<null>");
+  }
+
+  let treeOwner =
+    ui.prompt && ui.prompt.docShell && ui.prompt.docShell.treeOwner;
+  if (treeOwner && treeOwner.QueryInterface(Ci.nsIInterfaceRequestor)) {
+    // Check that the dialog is modal, chrome and dependent;
+    // We can't just check window.opener because that'll be
+    // a content window, which therefore isn't exposed (it'll lie and
+    // be null).
+    let flags = treeOwner.getInterface(Ci.nsIAppWindow).chromeFlags;
+    state.chrome = (flags & Ci.nsIWebBrowserChrome.CHROME_OPENAS_CHROME) != 0;
+    state.dialog = (flags & Ci.nsIWebBrowserChrome.CHROME_OPENAS_DIALOG) != 0;
+    state.chromeDependent =
+      (flags & Ci.nsIWebBrowserChrome.CHROME_DEPENDENT) != 0;
+    let wbc = treeOwner.getInterface(Ci.nsIWebBrowserChrome);
+    state.isWindowModal = wbc.isWindowModal();
+  }
+
+  // Check the dialog is a common dialog document and has been embedded.
+  let isEmbedded = !!ui.prompt?.docShell?.chromeEventHandler;
+  let isCommonDialogDoc = getDialogDoc()?.location.href.includes(
+    "commonDialog.xhtml"
+  );
+  state.isSubDialogPrompt = isCommonDialogDoc && isEmbedded;
+  state.showCallerOrigin = ui.prompt.args.showCallerOrigin;
+
+  return state;
+}
+
+function dismissSelect(ui, action) {
+  let dialog = ui.getElementsByTagName("dialog")[0];
+  let listbox = ui.getElementById("list");
+
+  if (action.selectItem) {
+    listbox.selectedIndex = 1;
+  }
+
+  if (action.buttonClick == "ok") {
+    dialog.acceptDialog();
+  } else if (action.buttonClick == "cancel") {
+    dialog.cancelDialog();
+  }
+}
+
+function dismissPrompt(ui, action) {
+  info(`dismissPrompt: action=${JSON.stringify(action)}`);
+  if (action.setCheckbox) {
+    // Annoyingly, the prompt code is driven by oncommand.
+    ui.checkbox.checked = true;
+    ui.checkbox.doCommand();
+  }
+
+  if ("textField" in action) {
+    ui.loginTextbox.setAttribute("value", action.textField);
+  }
+
+  if ("passField" in action) {
+    ui.password1Textbox.setAttribute("value", action.passField);
+  }
+
+  switch (action.buttonClick) {
+    case "ok":
+    case 0:
+      ui.button0.click();
+      break;
+    case "cancel":
+    case 1:
+      ui.button1.click();
+      break;
+    case 2:
+      ui.button2.click();
+      break;
+    case "ESC":
+      // XXX This is assuming tab-modal.
+      let browserWin = Services.wm.getMostRecentWindow("navigator:browser");
+      EventUtils.synthesizeKey("KEY_Escape", {}, browserWin);
+      break;
+    case "pollOK":
+      // Buttons are disabled at the moment, poll until they're reenabled.
+      // Can't use setInterval here, because the window's in a modal state
+      // and thus DOM events are suppressed.
+      let interval = setInterval(() => {
+        if (ui.button0.disabled) {
+          return;
+        }
+        ui.button0.click();
+        clearInterval(interval);
+      }, 100);
+      break;
+    case "none":
+      break;
+
+    default:
+      throw new Error("dismissPrompt action listed unknown button.");
+  }
+}
+
+function getDialogDoc() {
+  // Trudge through all the open windows, until we find the one
+  // that has either commonDialog.xhtml or selectDialog.xhtml loaded.
+  // var enumerator = Services.wm.getEnumerator("navigator:browser");
+  for (let { docShell } of Services.wm.getEnumerator(null)) {
+    var containedDocShells = docShell.getAllDocShellsInSubtree(
+      docShell.typeChrome,
+      docShell.ENUMERATE_FORWARDS
+    );
+    for (let childDocShell of containedDocShells) {
+      // Get the corresponding document for this docshell
+      // We don't want it if it's not done loading.
+      if (childDocShell.busyFlags != Ci.nsIDocShell.BUSY_FLAGS_NONE) {
+        continue;
+      }
+      var childDoc = childDocShell.contentViewer.DOMDocument;
+
+      if (
+        childDoc.location.href !=
+          "chrome://global/content/commonDialog.xhtml" &&
+        childDoc.location.href != "chrome://global/content/selectDialog.xhtml"
+      ) {
+        continue;
+      }
+
+      // We're expecting the dialog to be focused. If it's not yet, try later.
+      // (In particular, this is needed on Linux to reliably check focused elements.)
+      if (Services.focus.focusedWindow != childDoc.defaultView) {
+        continue;
+      }
+
+      return childDoc;
+    }
+  }
+
+  return null;
+}
diff --git a/toolkit/components/prompts/test/mochitest.ini b/toolkit/components/prompts/test/mochitest.ini
new file mode 100644
index 0000000000..6f00eb3815
--- /dev/null
+++ b/toolkit/components/prompts/test/mochitest.ini
@@ -0,0 +1,17 @@
+[DEFAULT]
+support-files =
+  ../../passwordmgr/test/authenticate.sjs
+  bug619644_inner.html
+  bug625187_iframe.html
+  prompt_common.js
+  chromeScript.js
+
+[test_bug619644.html]
+skip-if = toolkit == 'android' # No tab prompts on android
+[test_bug620145.html]
+skip-if = toolkit == 'android' #TIMED_OUT
+[test_subresources_prompts.html]
+skip-if = toolkit == 'android' || verify
+fail-if = xorigin
+[test_dom_prompts.html]
+skip-if = toolkit == 'android' #android: bug 1267092
diff --git a/toolkit/components/prompts/test/prompt_common.js b/toolkit/components/prompts/test/prompt_common.js
new file mode 100644
index 0000000000..a47d421d3c
--- /dev/null
+++ b/toolkit/components/prompts/test/prompt_common.js
@@ -0,0 +1,444 @@
+const { Cc, Ci, Cu: ChromeUtils } = SpecialPowers;
+
+/**
+ * Converts a property bag to object.
+ * @param {nsIPropertyBag} bag - The property bag to convert
+ * @returns {Object} - The object representation of the nsIPropertyBag
+ */
+function propBagToObject(bag) {
+  if (!(bag instanceof Ci.nsIPropertyBag)) {
+    throw new TypeError("Not a property bag");
+  }
+  let result = {};
+  for (let { name, value } of bag.enumerator) {
+    result[name] = value;
+  }
+  return result;
+}
+
+var modalType;
+var tabSubDialogsEnabled = SpecialPowers.Services.prefs.getBoolPref(
+  "prompts.tabChromePromptSubDialog",
+  false
+);
+var contentSubDialogsEnabled = SpecialPowers.Services.prefs.getBoolPref(
+  "prompts.contentPromptSubDialog",
+  false
+);
+var isSelectDialog = false;
+var isOSX = "nsILocalFileMac" in SpecialPowers.Ci;
+var isE10S = SpecialPowers.Services.appinfo.processType == 2;
+
+var gChromeScript = SpecialPowers.loadChromeScript(
+  SimpleTest.getTestFileURL("chromeScript.js")
+);
+SimpleTest.registerCleanupFunction(() => gChromeScript.destroy());
+
+async function runPromptCombinations(window, testFunc) {
+  let util = new PromptTestUtil(window);
+  let run = () => {
+    info(
+      `Running tests (modalType=${modalType}, usePromptService=${util.usePromptService}, useBrowsingContext=${util.useBrowsingContext}, useAsync=${util.useAsync})`
+    );
+    return testFunc(util);
+  };
+
+  // Prompt service with dom window parent only supports window prompts
+  util.usePromptService = true;
+  util.useBrowsingContext = false;
+  util.modalType = Ci.nsIPrompt.MODAL_TYPE_WINDOW;
+  modalType = util.modalType;
+  util.useAsync = false;
+  await run();
+
+  let modalTypes = [
+    Ci.nsIPrompt.MODAL_TYPE_WINDOW,
+    Ci.nsIPrompt.MODAL_TYPE_TAB,
+    Ci.nsIPrompt.MODAL_TYPE_CONTENT,
+  ];
+
+  for (let type of modalTypes) {
+    util.modalType = type;
+    modalType = type;
+
+    // Prompt service with browsing context sync
+    util.usePromptService = true;
+    util.useBrowsingContext = true;
+    util.useAsync = false;
+    await run();
+
+    // Prompt service with browsing context async
+    util.usePromptService = true;
+    util.useBrowsingContext = true;
+    util.useAsync = true;
+    await run();
+
+    // nsIPrompt
+    // modalType is set via nsIWritablePropertyBag (legacy)
+    util.usePromptService = false;
+    util.useBrowsingContext = false;
+    util.useAsync = false;
+    await run();
+  }
+}
+
+class PromptTestUtil {
+  constructor(window) {
+    this.window = window;
+    this.browsingContext = SpecialPowers.wrap(
+      window
+    ).windowGlobalChild.browsingContext;
+    this.promptService = SpecialPowers.Services.prompt;
+    this.nsPrompt = Cc["@mozilla.org/prompter;1"]
+      .getService(Ci.nsIPromptFactory)
+      .getPrompt(window, Ci.nsIPrompt);
+
+    this.usePromptService = null;
+    this.useBrowsingContext = null;
+    this.useAsync = null;
+    this.modalType = null;
+  }
+
+  get _prompter() {
+    if (this.usePromptService) {
+      return this.promptService;
+    }
+    return this.nsPrompt;
+  }
+
+  async prompt(funcName, promptArgs) {
+    if (
+      this.useBrowsingContext == null ||
+      this.usePromptService == null ||
+      this.useAsync == null ||
+      this.modalType == null
+    ) {
+      throw new Error("Not initialized");
+    }
+    let args = [];
+    if (this.usePromptService) {
+      if (this.useBrowsingContext) {
+        if (this.useAsync) {
+          funcName = `async${funcName[0].toUpperCase()}${funcName.substring(
+            1
+          )}`;
+        } else {
+          funcName += "BC";
+        }
+        args = [this.browsingContext, this.modalType];
+      } else {
+        args = [this.window];
+      }
+    } else {
+      let bag = this.nsPrompt.QueryInterface(Ci.nsIWritablePropertyBag2);
+      bag.setPropertyAsUint32("modalType", this.modalType);
+    }
+    // Append the prompt arguments
+    args = args.concat(promptArgs);
+
+    let interfaceName = this.usePromptService ? "Services.prompt" : "prompt";
+    ok(
+      this._prompter[funcName],
+      `${interfaceName} should have method ${funcName}.`
+    );
+
+    info(`Calling ${interfaceName}.${funcName}(${args})`);
+    let result = this._prompter[funcName](...args);
+    is(
+      this.useAsync,
+      result != null &&
+        result.constructor != null &&
+        result.constructor.name === "Promise",
+      "If method is async it should return a promise."
+    );
+
+    if (this.useAsync) {
+      let propBag = await result;
+      return propBag && propBagToObject(propBag);
+    }
+    return result;
+  }
+}
+
+function onloadPromiseFor(id) {
+  var iframe = document.getElementById(id);
+  return new Promise(resolve => {
+    iframe.addEventListener(
+      "load",
+      function(e) {
+        resolve(true);
+      },
+      { once: true }
+    );
+  });
+}
+
+/**
+ * Take an action on the next prompt that appears without checking the state in advance.
+ * This is useful when the action doesn't depend on which prompt is shown and you
+ * are expecting multiple prompts at once in an indeterminate order.
+ * If you know the state of the prompt you expect you should use `handlePrompt` instead.
+ * @param {object} action defining how to handle the prompt
+ * @returns {Promise} resolving with the prompt state.
+ */
+function handlePromptWithoutChecks(action) {
+  return new Promise(resolve => {
+    gChromeScript.addMessageListener("promptHandled", function handled(msg) {
+      gChromeScript.removeMessageListener("promptHandled", handled);
+      resolve(msg.promptState);
+    });
+    gChromeScript.sendAsyncMessage("handlePrompt", { action, modalType });
+  });
+}
+
+async function handlePrompt(state, action) {
+  let actualState = await handlePromptWithoutChecks(action);
+  checkPromptState(actualState, state);
+}
+
+function checkPromptState(promptState, expectedState) {
+  info(`checkPromptState: Expected: ${expectedState.msg}`);
+  // XXX check title? OS X has title in content
+  is(promptState.msg, expectedState.msg, "Checking expected message");
+
+  let isOldContentPrompt =
+    !promptState.isSubDialogPrompt &&
+    modalType === Ci.nsIPrompt.MODAL_TYPE_CONTENT;
+
+  if (isOldContentPrompt && !promptState.showCallerOrigin) {
+    ok(
+      promptState.titleHidden,
+      "The title should be hidden for content prompts opened with tab modal prompt."
+    );
+  } else if (
+    isOSX ||
+    promptState.isSubDialogPrompt ||
+    promptState.showCallerOrigin
+  ) {
+    ok(
+      !promptState.titleHidden,
+      "Checking title always visible on OS X or when opened with common dialog"
+    );
+  } else {
+    is(
+      promptState.titleHidden,
+      expectedState.titleHidden,
+      "Checking title visibility"
+    );
+  }
+  is(
+    promptState.textHidden,
+    expectedState.textHidden,
+    "Checking textbox visibility"
+  );
+  is(
+    promptState.passHidden,
+    expectedState.passHidden,
+    "Checking passbox visibility"
+  );
+  is(
+    promptState.checkHidden,
+    expectedState.checkHidden,
+    "Checking checkbox visibility"
+  );
+  is(promptState.checkMsg, expectedState.checkMsg, "Checking checkbox label");
+  is(promptState.checked, expectedState.checked, "Checking checkbox checked");
+  if (
+    modalType === Ci.nsIPrompt.MODAL_TYPE_WINDOW ||
+    (modalType === Ci.nsIPrompt.MODAL_TYPE_TAB && tabSubDialogsEnabled)
+  ) {
+    is(
+      promptState.iconClass,
+      expectedState.iconClass,
+      "Checking expected icon CSS class"
+    );
+  }
+  is(promptState.textValue, expectedState.textValue, "Checking textbox value");
+  is(promptState.passValue, expectedState.passValue, "Checking passbox value");
+
+  if (expectedState.butt0Label) {
+    is(
+      promptState.butt0Label,
+      expectedState.butt0Label,
+      "Checking accept-button label"
+    );
+  }
+  if (expectedState.butt1Label) {
+    is(
+      promptState.butt1Label,
+      expectedState.butt1Label,
+      "Checking cancel-button label"
+    );
+  }
+  if (expectedState.butt2Label) {
+    is(
+      promptState.butt2Label,
+      expectedState.butt2Label,
+      "Checking extra1-button label"
+    );
+  }
+
+  // For prompts with a time-delay button.
+  if (expectedState.butt0Disabled) {
+    is(promptState.butt0Disabled, true, "Checking accept-button is disabled");
+    is(
+      promptState.butt1Disabled,
+      false,
+      "Checking cancel-button isn't disabled"
+    );
+  }
+
+  is(
+    promptState.defButton0,
+    expectedState.defButton == "button0",
+    "checking button0 default"
+  );
+  is(
+    promptState.defButton1,
+    expectedState.defButton == "button1",
+    "checking button1 default"
+  );
+  is(
+    promptState.defButton2,
+    expectedState.defButton == "button2",
+    "checking button2 default"
+  );
+
+  if (
+    isOSX &&
+    expectedState.focused &&
+    expectedState.focused.startsWith("button") &&
+    !promptState.infoRowHidden
+  ) {
+    is(
+      promptState.focused,
+      "infoBody",
+      "buttons don't focus on OS X, but infoBody does instead"
+    );
+  } else {
+    is(promptState.focused, expectedState.focused, "Checking focused element");
+  }
+
+  if (expectedState.hasOwnProperty("chrome")) {
+    is(
+      promptState.chrome,
+      expectedState.chrome,
+      "Dialog should be opened as chrome"
+    );
+  }
+  if (expectedState.hasOwnProperty("dialog")) {
+    is(
+      promptState.dialog,
+      expectedState.dialog,
+      "Dialog should be opened as a dialog"
+    );
+  }
+  if (expectedState.hasOwnProperty("chromeDependent")) {
+    is(
+      promptState.chromeDependent,
+      expectedState.chromeDependent,
+      "Dialog should be opened as dependent"
+    );
+  }
+  if (expectedState.hasOwnProperty("isWindowModal")) {
+    is(
+      promptState.isWindowModal,
+      expectedState.isWindowModal,
+      "Dialog should be modal"
+    );
+  }
+}
+
+function checkEchoedAuthInfo(expectedState, browsingContext) {
+  return SpecialPowers.spawn(
+    browsingContext,
+    [expectedState.user, expectedState.pass],
+    (expectedUser, expectedPass) => {
+      let doc = this.content.document;
+
+      // The server echos back the HTTP auth info it received.
+      let username = doc.getElementById("user").textContent;
+      let password = doc.getElementById("pass").textContent;
+      let authok = doc.getElementById("ok").textContent;
+
+      Assert.equal(authok, "PASS", "Checking for successful authentication");
+      Assert.equal(username, expectedUser, "Checking for echoed username");
+      Assert.equal(password, expectedPass, "Checking for echoed password");
+    }
+  );
+}
+
+/**
+ * Create a Proxy to relay method calls on an nsIAuthPrompt[2] prompter to a chrome script which can
+ * perform the calls in the parent. Out and inout params will be copied back from the parent to
+ * content.
+ *
+ * @param chromeScript The reference to the chrome script that will listen to `proxyPrompter`
+ *                     messages in the parent and call the `methodName` method.
+ *                     The return value from the message handler should be an object with properties:
+ * `rv` - containing the return value of the method call.
+ * `args` - containing the array of arguments passed to the method since out or inout ones could have
+ *          been modified.
+ */
+function PrompterProxy(chromeScript) {
+  return new Proxy(
+    {},
+    {
+      get(target, prop, receiver) {
+        return (...args) => {
+          // Array of indices of out/inout params to copy from the parent back to the caller.
+          let outParams = [];
+
+          switch (prop) {
+            case "prompt": {
+              outParams = [/* result */ 5];
+              break;
+            }
+            case "promptAuth": {
+              outParams = [];
+              break;
+            }
+            case "promptPassword": {
+              outParams = [/* pwd */ 4];
+              break;
+            }
+            case "promptUsernameAndPassword": {
+              outParams = [/* user */ 4, /* pwd */ 5];
+              break;
+            }
+            default: {
+              throw new Error("Unknown nsIAuthPrompt method");
+            }
+          }
+
+          let result;
+          chromeScript
+            .sendQuery("proxyPrompter", {
+              args,
+              methodName: prop,
+            })
+            .then(val => {
+              result = val;
+            });
+          SpecialPowers.Services.tm.spinEventLoopUntil(
+            "Test(prompt_common.js:get)",
+            () => result
+          );
+
+          for (let outParam of outParams) {
+            // Copy the out or inout param value over the original
+            args[outParam].value = result.args[outParam].value;
+          }
+
+          if (prop == "promptAuth") {
+            args[2].username = result.args[2].username;
+            args[2].password = result.args[2].password;
+            args[2].domain = result.args[2].domain;
+          }
+
+          return result.rv;
+        };
+      },
+    }
+  );
+}
diff --git a/toolkit/components/prompts/test/test_bug619644.html b/toolkit/components/prompts/test/test_bug619644.html
new file mode 100644
index 0000000000..2b424c71a6
--- /dev/null
+++ b/toolkit/components/prompts/test/test_bug619644.html
@@ -0,0 +1,74 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=619644
+-->
+<head>
+  <title>Test for Bug 619644</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/EventUtils.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=619644">Mozilla Bug 619644</a>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+// This is a little yucky, but it works
+// The contents of bug619644_inner.html
+const expectedFinalDoc =
+"<head><\/head><body><p>Original content<\/p>\n<script>\n    window.opener.postMessage(\"\", \"*\");\n    confirm(\"Message\");\n    document.write(\"Extra content\");\n    window.opener.postMessage(document.documentElement.innerHTML, \"*\");\n<\/script>Extra content<\/body>";
+
+inittest();
+
+var promptDone;
+
+function inittest() {
+  window.addEventListener("message", runtest);
+  window.open("bug619644_inner.html", "619644");
+
+  SimpleTest.waitForExplicitFinish();
+}
+
+function runtest(e) {
+  modalType = Ci.nsIPrompt.MODAL_TYPE_CONTENT;
+
+  window.removeEventListener("message", runtest);
+  window.addEventListener("message", checktest);
+
+  let state = {
+      msg: "Message",
+      iconClass: "question-icon",
+      titleHidden: true,
+      textHidden: true,
+      passHidden: true,
+      checkHidden: true,
+      textValue: "",
+      passValue: "",
+      checkMsg: "",
+      checked: false,
+      focused: "button0",
+      defButton: "button0",
+  };
+  let action = {
+      buttonClick: "ESC",
+  };
+
+  promptDone = handlePrompt(state, action);
+}
+
+function checktest(e) {
+  is(e.data, expectedFinalDoc, "ESC press should not abort document load");
+  e.source.close();
+  promptDone.then(endtest);
+}
+
+function endtest() {
+  info("Ending test");
+  SimpleTest.finish();
+}
+</script>
+</pre>
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/test_bug620145.html b/toolkit/components/prompts/test/test_bug620145.html
new file mode 100644
index 0000000000..3894a528ae
--- /dev/null
+++ b/toolkit/components/prompts/test/test_bug620145.html
@@ -0,0 +1,96 @@
+<html>
+<head>
+  <title>Test for Bug 620145</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/EventUtils.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=620145">Mozilla Bug 620145</a>
+<pre id="test">
+</pre>
+
+<div id="text" style="max-width: 100px" onmouseup="openAlert()">
+  This is a short piece of text used for testing that mouse selecting is
+  stopped when an alert appears.
+</div>
+<div id="text2" style="max-width: 100px">
+  This is another short piece of text used for testing that mouse selecting is
+  stopped when an alert appears.
+</div>
+<button id="button" onmouseup="openAlert()">Button</button>
+
+<script class="testbody" type="text/javascript">
+
+function openAlert() {
+  info("opening alert...");
+  alert("hello!");
+  info("...alert done.");
+}
+
+add_task(async function runTest() {
+  var state, action;
+  // The <button> in this test's HTML opens a prompt when clicked.
+  // Here we send the events to simulate clicking it.
+  modalType = Ci.nsIPrompt.MODAL_TYPE_CONTENT;
+
+  state = {
+    msg: "hello!",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  let promptDone = handlePrompt(state, action);
+
+  var button = $("button");
+  dispatchMouseEvent(button, "mousedown");
+  dispatchMouseEvent(button, "mouseup");
+  // alert appears at this point, to be closed by the chrome script.
+
+  await promptDone;
+  checkSelection();
+
+  // using same state and action.
+  promptDone = handlePrompt(state, action);
+
+  var text = $("text");
+  dispatchMouseEvent(text, "mousedown");
+  dispatchMouseEvent(text, "mouseup");
+  // alert appears at this point, to be closed by the chrome script.
+
+  await promptDone;
+  checkSelection();
+});
+
+function dispatchMouseEvent(target, type) {
+  var win = target.ownerDocument.defaultView;
+  let e = document.createEvent("MouseEvent");
+  e.initEvent(type, false, false, win, 0, 1, 1, 1, 1,
+              false, false, false, false, 0, null);
+  var utils = SpecialPowers.getDOMWindowUtils(win);
+  utils.dispatchDOMEventViaPresShellForTesting(target, e);
+  ok(true, type + " sent to " + target.id);
+}
+
+function checkSelection() {
+  synthesizeMouse($("text"), 25, 55, { type: "mousemove" });
+  is(window.getSelection().toString(), "", "selection not made");
+}
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/test_dom_prompts.html b/toolkit/components/prompts/test/test_dom_prompts.html
new file mode 100644
index 0000000000..95595b8df2
--- /dev/null
+++ b/toolkit/components/prompts/test/test_dom_prompts.html
@@ -0,0 +1,207 @@
+<html>
+<head>
+  <title>Test for DOM prompts</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/EventUtils.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<pre id="test">
+</pre>
+
+<script class="testbody" type="text/javascript">
+var rv;
+var state, action;
+modalType = Ci.nsIPrompt.MODAL_TYPE_CONTENT;
+
+add_task(async function test_alert_ok() {
+    info("Starting test: Alert");
+    state = {
+        msg: "This is the alert text.",
+        iconClass: "alert-icon",
+        titleHidden: true,
+        textHidden: true,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "button0",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    alert("This is the alert text.");
+
+    await promptDone;
+});
+
+// bug 861605 made the arguments to alert/confirm optional (prompt already was).
+add_task(async function test_alert_noargs() {
+    info("Starting test: Alert with no args");
+    state = {
+        msg: "",
+        iconClass: "alert-icon",
+        titleHidden: true,
+        textHidden: true,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "button0",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    try {
+        alert();
+        ok(true, "alert() without arguments should not throw!");
+    } catch (e) {
+        ok(false, "alert() without arguments should not throw!");
+    }
+
+    await promptDone;
+});
+
+add_task(async function test_confirm_ok() {
+    info("Starting test: Confirm");
+    state = {
+        msg: "This is the confirm text.",
+        iconClass: "question-icon",
+        titleHidden: true,
+        textHidden: true,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "button0",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    rv = confirm("This is the confirm text.");
+    is(rv, true, "check prompt return value");
+
+    await promptDone;
+});
+
+// bug 861605 made the arguments to alert/confirm optional (prompt already was).
+add_task(async function test_confirm_noargs() {
+    info("Starting test: Confirm with no args");
+    state = {
+        msg: "",
+        iconClass: "question-icon",
+        titleHidden: true,
+        textHidden: true,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "button0",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    try {
+        rv = confirm();
+        ok(true, "confirm() without arguments should not throw!");
+    } catch (e) {
+        ok(false, "confirm() without arguments should not throw!");
+    }
+    is(rv, true, "check prompt return value");
+
+    await promptDone;
+});
+
+
+add_task(async function test_prompt_ok() {
+    info("Starting test: Prompt");
+    state = {
+        msg: "This is the Prompt text.",
+        iconClass: "question-icon",
+        titleHidden: true,
+        textHidden: false,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "textField",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    rv = prompt("This is the Prompt text.");
+    is(rv, "", "check prompt return value");
+
+    await promptDone;
+});
+
+// bug 861605 made the arguments to alert/confirm optional (prompt already was).
+add_task(async function test_prompt_noargs() {
+    info("Starting test: Prompt with no args");
+    state = {
+        msg: "",
+        iconClass: "question-icon",
+        titleHidden: true,
+        textHidden: false,
+        passHidden: true,
+        checkHidden: true,
+        textValue: "",
+        passValue: "",
+        checkMsg: "",
+        checked: false,
+        focused: "textField",
+        defButton: "button0",
+    };
+    action = {
+        buttonClick: "ok",
+    };
+
+    let promptDone = handlePrompt(state, action);
+
+    try {
+        rv = prompt();
+        ok(true, "prompt() without arguments should not throw!");
+    } catch (e) {
+        ok(false, "prompt() without arguments should not throw!");
+    }
+    is(rv, "", "check prompt return value");
+
+    await promptDone;
+});
+
+</script>
+
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/test_modal_prompts.html b/toolkit/components/prompts/test/test_modal_prompts.html
new file mode 100644
index 0000000000..df3438dbba
--- /dev/null
+++ b/toolkit/components/prompts/test/test_modal_prompts.html
@@ -0,0 +1,1311 @@
+
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Modal Prompts Test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+</head>
+<body>
+Prompter tests: modal prompts
+<p id="display"></p>
+
+<div id="content" style="display: none">
+  <iframe id="iframe"></iframe>
+</div>
+
+<pre id="test">
+<script class="testbody" type="text/javascript">
+/* eslint-disable complexity */
+async function runTests(util) {
+  const { NetUtil } = SpecialPowers.ChromeUtils.import(
+    "resource://gre/modules/NetUtil.jsm"
+  );
+
+  // The ConfirmEx + delay test has slightly different behavior with the focus
+  // fixup rule vs. without.
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.focus.fixup", true]],
+  });
+
+  let state, action, promptDone;
+
+  let checkVal = {};
+  let textVal = {};
+  let passVal = {};
+  let flags;
+  let isOK;
+
+  // =====
+  info("Starting test: Alert");
+  state = {
+    msg: "This is the alert text.",
+    title: "TestTitle",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = ["TestTitle", "This is the alert text."];
+  await util.prompt("alert", promptArgs);
+
+  await promptDone;
+
+  // =====
+  info("Starting test: AlertCheck (null checkbox label, so it's hidden)");
+  state = {
+    msg: "This is the alertCheck text.",
+    title: "TestTitle",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = [
+    "TestTitle",
+    "This is the alertCheck text.",
+    null,
+    util.useAsync ? false : {},
+  ];
+  util.prompt("alertCheck", promptArgs);
+
+  await promptDone;
+
+  // =====
+  info("Starting test: AlertCheck");
+  state = {
+    msg: "This is the alertCheck text.",
+    title: "TestTitle",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the alertCheck text.",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  let result = await util.prompt("alertCheck", promptArgs);
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "checkbox was checked"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Confirm (ok)");
+  state = {
+    msg: "This is the confirm text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = ["TestTitle", "This is the confirm text."];
+  result = await util.prompt("confirm", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Confirm (cancel)");
+  state = {
+    msg: "This is the confirm text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = ["TestTitle", "This is the confirm text."];
+  result = await util.prompt("confirm", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmCheck (ok, null checkbox label)");
+  state = {
+    msg: "This is the confirmCheck text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmCheck text.",
+    null,
+    util.useAsync ? false : {},
+  ];
+  result = await util.prompt("confirmCheck", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmCheck (cancel, null checkbox label)");
+  state = {
+    msg: "This is the confirmCheck text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmCheck text.",
+    null,
+    util.useAsync ? false : {},
+  ];
+  result = await util.prompt("confirmCheck", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmCheck (ok)");
+  state = {
+    msg: "This is the confirmCheck text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmCheck text.",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("confirmCheck", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmCheck (cancel)");
+  state = {
+    msg: "This is the confirmCheck text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmCheck text.",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("confirmCheck", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (ok, no default text)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "bacon",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "";
+  promptArgs = ["TestTitle", "This is the prompt text.", util.useAsync ? textVal.value : textVal , null, util.useAsync ? false : {}];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "bacon",
+    "checking expected text value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (ok, default text)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "kittens",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "kittens";
+  promptArgs = ["TestTitle", "This is the prompt text.", util.useAsync ? textVal.value : textVal, null, util.useAsync ? false : {}];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "kittens",
+    "checking expected text value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (cancel, default text)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "puppies",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "puppies";
+  promptArgs = ["TestTitle", "This is the prompt text.", util.useAsync ? textVal.value : textVal, null, util.useAsync ? false : {}];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "puppies",
+    "checking expected text value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (cancel, default text modified)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "puppies",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+    textField: "bacon",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "puppies";
+  promptArgs = ["TestTitle", "This is the prompt text.", util.useAsync ? textVal.value : textVal, null, util.useAsync ? false : {}];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "puppies",
+    "checking expected text value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (ok, with checkbox)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "tribbles",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "tribbles";
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the prompt text.",
+    util.useAsync ? textVal.value : textVal,
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "tribbles",
+    "checking expected text value"
+  );
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: Prompt (cancel, with checkbox)");
+  state = {
+    msg: "This is the prompt text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "tribbles",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+    setCheckbox: true,
+  };
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "tribbles";
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the prompt text.",
+    util.useAsync ? textVal.value : textVal,
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("prompt", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  is(
+    util.useAsync ? result.value : textVal.value,
+    "tribbles",
+    "checking expected text value"
+  );
+  ok(
+    util.useAsync ? result.checked : !checkVal.value,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  // Just two tests for this, since password manager already tests this extensively.
+  info("Starting test: PromptUsernameAndPassword (ok)");
+  state = {
+    msg: "This is the pUAP text.",
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "usr",
+    passValue: "ssh",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "newusr",
+    passField: "newssh",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "usr";
+  passVal.value = "ssh";
+  promptArgs = [
+    "TestTitle",
+    "This is the pUAP text.",
+    util.useAsync ? textVal.value : textVal,
+    util.useAsync ? passVal.value : passVal
+  ];
+  result = await util.prompt("promptUsernameAndPassword", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.user : textVal.value,
+    "newusr",
+    "checking expected text value"
+  );
+  is(
+    util.useAsync ? result.pass : passVal.value,
+    "newssh",
+    "checking expected pass value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: PromptUsernameAndPassword (cancel)");
+  state = {
+    msg: "This is the pUAP text.",
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "usr",
+    passValue: "ssh",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+    textField: "newusr",
+    passField: "newssh",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  textVal.value = "usr";
+  passVal.value = "ssh";
+  promptArgs = [
+    "TestTitle",
+    "This is the pUAP text.",
+    util.useAsync ? textVal.value : textVal,
+    util.useAsync ? passVal.value : passVal
+  ];
+  result = await util.prompt("promptUsernameAndPassword", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  ok(
+    (util.useAsync && result.user == "newusr") || textVal.value == "usr",
+    "checking expected text value"
+  );
+  ok(
+    (util.useAsync && result.pass == "newpass") || passVal.value == "ssh",
+    "checking expected pass value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: PromptPassword (ok)");
+  state = {
+    msg: "This is the promptPassword text.",
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "ssh",
+    focused: "passField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    passField: "newssh",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  passVal.value = "ssh";
+  promptArgs = [
+    "TestTitle",
+    "This is the promptPassword text.",
+    util.useAsync ? passVal.value : passVal
+  ];
+  result = await util.prompt("promptPassword", promptArgs);
+  is(util.useAsync ? result.ok : result, true, "checked expected retval");
+  is(
+    util.useAsync ? result.pass : passVal.value,
+    "newssh",
+    "checking expected pass value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: PromptPassword (cancel)");
+  state = {
+    msg: "This is the promptPassword text.",
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "ssh",
+    focused: "passField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "cancel",
+    passField: "newssh",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  passVal.value = "ssh";
+  promptArgs = [
+    "TestTitle",
+    "This is the promptPassword text.",
+    util.useAsync ? passVal.value : passVal
+  ];
+  result = await util.prompt("promptPassword", promptArgs);
+  is(util.useAsync ? result.ok : result, false, "checked expected retval");
+  ok(
+    (util.useAsync && result.pass == "newssh") || passVal.value == "ssh",
+    "checking expected pass value"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmEx (ok/cancel, ok)");
+  state = {
+    msg: "This is the confirmEx text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+    butt0Label: "OK",
+    butt1Label: "Cancel",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  flags = Ci.nsIPromptService.STD_OK_CANCEL_BUTTONS;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmEx text.",
+    flags,
+    null,
+    null,
+    null,
+    null,
+    util.useAsync ? false : {},
+  ];
+  result = await util.prompt("confirmEx", promptArgs);
+  is(
+    util.useAsync ? result.buttonNumClicked : result,
+    0,
+    "checked expected button num click"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmEx (yes/no, cancel)");
+  state = {
+    msg: "This is the confirmEx text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+    butt0Label: "Yes",
+    butt1Label: "No",
+  };
+  action = {
+    buttonClick: "cancel",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  flags = Ci.nsIPromptService.STD_YES_NO_BUTTONS;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmEx text.",
+    flags,
+    null,
+    null,
+    null,
+    null,
+    util.useAsync ? false : {},
+  ];
+  result = await util.prompt("confirmEx", promptArgs);
+  is(
+    util.useAsync ? result.buttonNumClicked : result,
+    1,
+    "checked expected button num click"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmEx (buttons from args, checkbox, ok)");
+  state = {
+    msg: "This is the confirmEx text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+    butt0Label: "butt0",
+    butt1Label: "butt1",
+    butt2Label: "butt2",
+  };
+  action = {
+    buttonClick: "ok",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  let b = Ci.nsIPromptService.BUTTON_TITLE_IS_STRING;
+  flags =
+    b * Ci.nsIPromptService.BUTTON_POS_2 +
+    b * Ci.nsIPromptService.BUTTON_POS_1 +
+    b * Ci.nsIPromptService.BUTTON_POS_0;
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmEx text.",
+    flags,
+    "butt0",
+    "butt1",
+    "butt2",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("confirmEx", promptArgs);
+  is(
+    util.useAsync ? result.buttonNumClicked : result,
+    0,
+    "checked expected button num click"
+  );
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmEx (buttons from args, checkbox, cancel)");
+  state = {
+    msg: "This is the confirmEx text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button1", // Default changed!
+    defButton: "button1",
+    butt0Label: "butt0",
+    butt1Label: "butt1",
+    butt2Label: "butt2",
+  };
+  action = {
+    buttonClick: "cancel",
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  b = Ci.nsIPromptService.BUTTON_TITLE_IS_STRING;
+  flags =
+    b * Ci.nsIPromptService.BUTTON_POS_2 +
+    b * Ci.nsIPromptService.BUTTON_POS_1 +
+    b * Ci.nsIPromptService.BUTTON_POS_0;
+  flags ^= Ci.nsIPromptService.BUTTON_POS_1_DEFAULT;
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmEx text.",
+    flags,
+    "butt0",
+    "butt1",
+    "butt2",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("confirmEx", promptArgs);
+  is(
+    util.useAsync ? result.buttonNumClicked : result,
+    1,
+    "checked expected button num click"
+  );
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  info("Starting test: ConfirmEx (buttons from args, checkbox, button3)");
+  state = {
+    msg: "This is the confirmEx text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: false,
+    textValue: "",
+    passValue: "",
+    checkMsg: "Check me out!",
+    checked: false,
+    focused: "button2", // Default changed!
+    defButton: "button2",
+    butt0Label: "butt0",
+    butt1Label: "butt1",
+    butt2Label: "butt2",
+  };
+  action = {
+    buttonClick: 2,
+    setCheckbox: true,
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  b = Ci.nsIPromptService.BUTTON_TITLE_IS_STRING;
+  flags =
+    b * Ci.nsIPromptService.BUTTON_POS_2 +
+    b * Ci.nsIPromptService.BUTTON_POS_1 +
+    b * Ci.nsIPromptService.BUTTON_POS_0;
+  flags ^= Ci.nsIPromptService.BUTTON_POS_2_DEFAULT;
+  checkVal.value = false;
+  promptArgs = [
+    "TestTitle",
+    "This is the confirmEx text.",
+    flags,
+    "butt0",
+    "butt1",
+    "butt2",
+    "Check me out!",
+    util.useAsync ? checkVal.value : checkVal,
+  ];
+  result = await util.prompt("confirmEx", promptArgs);
+  is(
+    util.useAsync ? result.buttonNumClicked : result,
+    2,
+    "checked expected button num click"
+  );
+  is(
+    util.useAsync ? result.checked : checkVal.value,
+    true,
+    "expected checkbox setting"
+  );
+
+  await promptDone;
+
+  // =====
+  // (skipped for E10S and tabmodal tests: window is required)
+  info("Starting test: Alert, no window");
+  state = {
+    msg: "This is the alert text.",
+    title: "TestTitle",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+  if (util.modalType === Ci.nsIPrompt.MODAL_TYPE_WINDOW && !isE10S) {
+    promptDone = handlePrompt(state, action);
+
+    promptArgs = ["TestTitle", "This is the alert text."];
+    await util.prompt("alert", promptArgs);
+
+    await promptDone;
+  }
+
+  // =====
+  // (skipped for tabmodal tests: delay not supported)
+  info("Starting test: ConfirmEx (delay, ok)");
+  state = {
+    msg: "This is the confirmEx delay text.",
+    title: "TestTitle",
+    iconClass: "question-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: null, // Nothing focused until the delay triggers.
+    defButton: "button0",
+    butt0Label: "OK",
+    butt1Label: "Cancel",
+    butt0Disabled: true,
+  };
+
+  if (isOSX) {
+    // OS X doesn't initially focus the button, but rather the infoBody.
+    // The focus stays there even after the button-enable delay has fired.
+    state.focused = "infoBody";
+  }
+
+  action = {
+    buttonClick: "pollOK",
+  };
+  if (util.modalType === Ci.nsIPrompt.MODAL_TYPE_WINDOW) {
+    promptDone = handlePrompt(state, action);
+
+    flags =
+      Ci.nsIPromptService.STD_OK_CANCEL_BUTTONS |
+      Ci.nsIPromptService.BUTTON_DELAY_ENABLE;
+    promptArgs = [
+      "TestTitle",
+      "This is the confirmEx delay text.",
+      flags,
+      null,
+      null,
+      null,
+      null,
+      util.useAsync ? false : {},
+    ];
+    result = await util.prompt("confirmEx", promptArgs);
+    is(
+      util.useAsync ? result.buttonNumClicked : result,
+      0,
+      "checked expected button num click"
+    );
+
+    await promptDone;
+  }
+
+  // promptAuth already tested via password manager but do a few specific things here.
+  var channel = NetUtil.newChannel({
+    uri: "http://example.com",
+    loadUsingSystemPrincipal: true,
+  });
+
+  var level = Ci.nsIAuthPrompt2.LEVEL_NONE;
+  var authinfo = {
+    username: "",
+    password: "",
+    domain: "",
+    flags: Ci.nsIAuthInformation.AUTH_HOST,
+    authenticationScheme: "basic",
+    realm: "",
+  };
+
+  let msg =
+    util.modalType == Ci.nsIPrompt.MODAL_TYPE_TAB
+      ? "This site is asking you to sign in."
+      : "http://example.com is requesting your username and password.";
+  // =====
+  // (promptAuth is only accessible from the prompt service)
+  info("Starting test: promptAuth with empty realm");
+  state = {
+    msg,
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "username",
+    passField: "password",
+  };
+  if (util.usePromptService && !util.useAsync) {
+    promptDone = handlePrompt(state, action);
+
+    promptArgs = [channel, level, authinfo];
+    isOK = await util.prompt("promptAuth", promptArgs);
+    is(isOK, true, "checked expected retval");
+    is(authinfo.username, "username", "checking filled username");
+    is(authinfo.password, "password", "checking filled password");
+
+    await promptDone;
+  }
+
+  // =====
+  // (promptAuth is only accessible from the prompt service)
+  msg =
+    util.modalType == Ci.nsIPrompt.MODAL_TYPE_TAB
+      ? "This site is asking you to sign in."
+      : "http://example.com is requesting your username and password. The site " +
+        "says: \u201cabcdefghi abcdefghi abcdefghi abcdefghi abcdefghi abcdefghi abcdefghi " +
+        "abcdefghi abcdefghi abcdefghi abcdefghi abcdefghi abcdefghi abcdefghi " +
+        "abcdefghi \u2026\u201d";
+
+  info("Starting test: promptAuth with long realm");
+  state = {
+    msg,
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "username",
+    passField: "password",
+  };
+  if (util.usePromptService && !util.useAsync) {
+    promptDone = handlePrompt(state, action);
+
+    var longString = "";
+    for (var i = 0; i < 20; i++) longString += "abcdefghi "; // 200 chars long
+    authinfo.realm = longString;
+    authinfo.username = "";
+    authinfo.password = "";
+    promptArgs = [channel, level, authinfo];
+    isOK = await util.prompt("promptAuth", promptArgs);
+    is(isOK, true, "checked expected retval");
+    is(authinfo.username, "username", "checking filled username");
+    is(authinfo.password, "password", "checking filled password");
+
+    await promptDone;
+  }
+
+  msg =
+    util.modalType == Ci.nsIPrompt.MODAL_TYPE_TAB
+      ? ("This site is asking you to sign in. Warning: Your login information " +
+        "will be shared with example.com, not the website you are currently visiting.")
+      : ("http://example.com is requesting your username and password. " +
+        "WARNING: Your password will not be sent to the website you are currently visiting!");
+  info("Starting test: promptAuth for a cross-origin and a empty realm");
+  authinfo = {
+    username: "",
+    password: "",
+    domain: "",
+    flags:
+      Ci.nsIAuthInformation.AUTH_HOST |
+      Ci.nsIAuthInformation.CROSS_ORIGIN_SUB_RESOURCE,
+    authenticationScheme: "basic",
+    realm: "",
+  };
+  state = {
+    msg,
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "username",
+    passField: "password",
+  };
+  if (util.usePromptService && !util.useAsync) {
+    promptDone = handlePrompt(state, action);
+    promptArgs = [channel, level, authinfo];
+    isOK = await util.prompt("promptAuth", promptArgs);
+    is(isOK, true, "checked expected retval");
+    is(authinfo.username, "username", "checking filled username");
+    is(authinfo.password, "password", "checking filled password");
+
+    await promptDone;
+  }
+
+  info("Starting test: promptAuth for a cross-origin with realm");
+  authinfo = {
+    username: "",
+    password: "",
+    domain: "",
+    flags:
+      Ci.nsIAuthInformation.AUTH_HOST |
+      Ci.nsIAuthInformation.CROSS_ORIGIN_SUB_RESOURCE,
+    authenticationScheme: "basic",
+    realm: "Something!!!",
+  };
+  state = {
+    msg, // Same as previous test, see above.
+    title: "TestTitle",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    textValue: "",
+    passValue: "",
+    focused: "textField",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+    textField: "username",
+    passField: "password",
+  };
+  if (util.usePromptService && !util.useAsync) {
+    promptDone = handlePrompt(state, action);
+
+    promptArgs = [channel, level, authinfo];
+    isOK = await util.prompt("promptAuth", promptArgs);
+    is(isOK, true, "checked expected retval");
+    is(authinfo.username, "username", "checking filled username");
+    is(authinfo.password, "password", "checking filled password");
+
+    await promptDone;
+  }
+}
+
+let promptArgs;
+
+add_task(async function runPromptTests() {
+  await runPromptCombinations(window, runTests);
+});
+</script>
+</pre>
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/test_modal_select.html b/toolkit/components/prompts/test/test_modal_select.html
new file mode 100644
index 0000000000..27688cf329
--- /dev/null
+++ b/toolkit/components/prompts/test/test_modal_select.html
@@ -0,0 +1,138 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Modal Prompts Test</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+</head>
+<body>
+Prompter tests: modal prompts
+<p id="display"></p>
+
+<div id="content" style="display: none">
+  <iframe id="iframe"></iframe>
+</div>
+
+<pre id="test">
+<script class="testbody" type="text/javascript">
+function checkPromptState(promptState, expectedState) {
+    // XXX check title? OS X has title in content
+    // XXX check focused element
+    // XXX check button labels?
+
+    is(promptState.msg, expectedState.msg, "Checking expected message");
+
+    // Compare listbox contents
+    is(promptState.items.length, expectedState.items.length, "Checking listbox length");
+
+    if (promptState.items.length)
+      is(promptState.selectedIndex, 0, "Checking selected index");
+
+    for (let i = 0; i < promptState.items; i++) {
+        is(promptState.items[i], expectedState.items[i], "Checking list item #" + i);
+    }
+}
+
+let selectVal = {};
+let isOK;
+
+function handlePrompt(state, action) {
+  return new Promise(resolve => {
+    gChromeScript.addMessageListener("promptHandled", function handled(msg) {
+      gChromeScript.removeMessageListener("promptHandled", handled);
+      checkPromptState(msg.promptState, state);
+      resolve(true);
+    });
+    gChromeScript.sendAsyncMessage("handlePrompt", { action, isSelect: true});
+  });
+}
+
+async function runTests(util) {
+    // Select prompt does not support tab or content prompts yet. See Bug 1622817.
+    if(util.modalType != Ci.nsIPrompt.MODAL_TYPE_WINDOW) {
+        info('Skipping modal type for select prompt...');
+        return;
+    }
+
+    // Empty list
+    info("Starting test: Select (0 items, ok)");
+    let state = {
+        msg: "This is the select text.",
+        title: "TestTitle",
+        items: [],
+    };
+    let action = {
+        buttonClick: "ok",
+    };
+    let promptDone = handlePrompt(state, action);
+    let items = [];
+    selectVal.value = null; // outparam, just making sure.
+    let result =  await util.prompt("select", ["TestTitle", "This is the select text.", items, util.useAsync ? false : selectVal]);
+    is(util.useAsync ? result.ok : result, true, "checked expected retval");
+    is(util.useAsync ? result.selected : selectVal.value, -1, "checking selected index");
+    await promptDone;
+
+    // ok
+    info("Starting test: Select (3 items, ok)");
+    state = {
+        msg: "This is the select text.",
+        title: "TestTitle",
+        items: ["one", "two", "three"],
+    };
+    action = {
+        buttonClick: "ok",
+    };
+    promptDone = handlePrompt(state, action);
+    items = ["one", "two", "three"];
+    selectVal.value = null; // outparam, just making sure.
+    result = await util.prompt("select", ["TestTitle", "This is the select text.", items, util.useAsync ? false : selectVal]);
+    is(util.useAsync ? result.ok : result, true, "checked expected retval");
+    is(util.useAsync ? result.selected : selectVal.value, 0, "checking selected index");
+    await promptDone;
+
+    // select item
+    info("Starting test: Select (3 items, selection changed, ok)");
+    state = {
+        msg: "This is the select text.",
+        title: "TestTitle",
+        items: ["one", "two", "three"],
+    };
+    action = {
+        buttonClick: "ok",
+        selectItem: 1,
+    };
+    promptDone = handlePrompt(state, action);
+    items = ["one", "two", "three"];
+    selectVal.value = null; // outparam, just making sure.
+    result = await util.prompt("select", ["TestTitle", "This is the select text.", items,  util.useAsync ? false : selectVal]);
+    is(util.useAsync ? result.ok : result, true, "checked expected retval");
+    is(util.useAsync ? result.selected : selectVal.value, 1, "checking selected index");
+    await promptDone;
+
+    // cancel prompt
+    info("Starting test: Select (3 items, cancel)");
+    state = {
+        msg: "This is the select text.",
+        title: "TestTitle",
+        items: ["one", "two", "three"],
+    };
+    action = {
+        buttonClick: "cancel",
+    };
+    promptDone = handlePrompt(state, action);
+    items = ["one", "two", "three"];
+    selectVal.value = null; // outparam, just making sure.
+    result = await util.prompt("select", ["TestTitle", "This is the select text.", items,  util.useAsync ? false : selectVal]);
+    is(util.useAsync ? result.ok : result, false, "checked expected retval");
+    ok(util.useAsync && result.selected == -1 || selectVal.value == 0, "checking selected index");
+    await promptDone;
+}
+
+add_task(async function runPromptTests() {
+    await runPromptCombinations(window, runTests);
+});
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/toolkit/components/prompts/test/test_subresources_prompts.html b/toolkit/components/prompts/test/test_subresources_prompts.html
new file mode 100644
index 0000000000..b71ad0694e
--- /dev/null
+++ b/toolkit/components/prompts/test/test_subresources_prompts.html
@@ -0,0 +1,200 @@
+<html>
+<head>
+  <title>Test subresources prompts (Bug 625187 and bug 1230462)</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="/tests/SimpleTest/EventUtils.js"></script>
+  <script type="text/javascript" src="prompt_common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+<!--
+   - Any copyright is dedicated to the Public Domain.
+   - http://creativecommons.org/publicdomain/zero/1.0/
+   -
+   - Contributor(s):
+   -   Mihai Sucan <mihai.sucan@gmail.com>
+   -->
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=625187">Mozilla Bug 625187</a>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1230462">Mozilla Bug 1230462</a>
+
+<p><button id="topbutton" onclick="alert('hello world')">Button</button></p>
+
+<iframe id="iframe_diff_origin" src="http://example.com/tests/toolkit/components/prompts/test/bug625187_iframe.html"></iframe>
+
+<iframe id="iframe_same_origin" src="bug625187_iframe.html"></iframe>
+
+<iframe id="iframe_prompt"></iframe>
+
+<pre id="test"></pre>
+
+<script class="testbody" type="text/javascript">
+var iframe1Loaded = onloadPromiseFor("iframe_diff_origin");
+var iframe2Loaded = onloadPromiseFor("iframe_same_origin");
+var iframe_prompt = document.getElementById("iframe_prompt");
+
+// Depending on pref state we either show auth prompts as windows or on tab level.
+let authPromptModalType = SpecialPowers.Services.prefs.getIntPref(
+  "prompts.modalType.httpAuth"
+);
+
+add_task(async function runTest() {
+  modalType = Ci.nsIPrompt.MODAL_TYPE_CONTENT;
+
+  info("Ensuring iframe1 has loaded...");
+  await iframe1Loaded;
+  info("Ensuring iframe2 has loaded...");
+  await iframe2Loaded;
+  let state, action;
+
+  state = {
+    msg: "hello world",
+    iconClass: "alert-icon",
+    titleHidden: true,
+    textHidden: true,
+    passHidden: true,
+    checkHidden: true,
+    textValue: "",
+    passValue: "",
+    checkMsg: "",
+    checked: false,
+    focused: "button0",
+    defButton: "button0",
+  };
+  action = {
+    buttonClick: "ok",
+  };
+
+  let promptDone = handlePrompt(state, action);
+
+  await SpecialPowers.spawn(window, ["topbutton", "click"], dispatchMouseEvent);
+
+  await promptDone;
+
+  // mostly reusing same state/action
+  state.titleHidden = false;
+  state.msg = "hello world 2";
+  promptDone = handlePrompt(state, action);
+
+  var iframe = document.getElementById("iframe_diff_origin");
+  await SpecialPowers.spawn(iframe.contentWindow, ["btn1", "click"], dispatchMouseEvent);
+
+  await promptDone;
+
+  // mostly reusing same state/action
+  state.titleHidden = true;
+  state.msg = "hello world 2";
+  promptDone = handlePrompt(state, action);
+
+  iframe = document.getElementById("iframe_same_origin");
+  await SpecialPowers.spawn(iframe.contentWindow, ["btn1", "click"], dispatchMouseEvent);
+
+  await promptDone;
+
+  // mostly reusing same state/action
+  state.msg = "hello world 3";
+  promptDone = handlePrompt(state, action);
+  await SpecialPowers.spawn(iframe.contentWindow, ["btn2", "click"], dispatchMouseEvent);
+
+  await promptDone;
+});
+
+add_task(async function runTestAuth() {
+  // Following tests check prompt message for a cross-origin and not
+  // cross-origin subresources load
+
+  // Let prompt_common know what kind of modal type is enabled for auth prompts.
+  modalType = authPromptModalType;
+
+  let state, action;
+
+  state = {
+    msg: "This site is asking you to sign in.",
+    title: "Authentication Required",
+    textValue: "",
+    passValue: "",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+
+  action = {
+    buttonClick: "ok",
+    setCheckbox: false,
+    textField: "mochiuser1",
+    passField: "mochipass1",
+  };
+
+  let promptDone = handlePrompt(state, action);
+
+  var iframe3Loaded = onloadPromiseFor("iframe_prompt");
+  iframe_prompt.src = "authenticate.sjs?user=mochiuser1&pass=mochipass1";
+  await promptDone;
+  await iframe3Loaded;
+  await checkEchoedAuthInfo({user: "mochiuser1", pass: "mochipass1"},
+                            iframe_prompt);
+
+  // Cross-origin subresourse test.
+  state = {
+    msg: "This site is asking you to sign in. Warning: Your login information " +
+      "will be shared with example.com, not the website you are currently visiting.",
+    title: "Authentication Required",
+    textValue: "",
+    passValue: "",
+    iconClass: "authentication-icon question-icon",
+    titleHidden: true,
+    textHidden: false,
+    passHidden: false,
+    checkHidden: true,
+    checkMsg: "",
+    checked: false,
+    focused: "textField",
+    defButton: "button0",
+  };
+
+  action = {
+    buttonClick: "ok",
+    setCheckbox: false,
+    textField: "mochiuser2",
+    passField: "mochipass2",
+  };
+
+  promptDone = handlePrompt(state, action);
+
+  iframe3Loaded = onloadPromiseFor("iframe_prompt");
+  iframe_prompt.src = "http://example.com/tests/toolkit/components/prompts/test/authenticate.sjs?user=mochiuser2&pass=mochipass2&realm=mochitest";
+  await promptDone;
+  await iframe3Loaded;
+  await checkEchoedAuthInfo({user: "mochiuser2", pass: "mochipass2"},
+                            iframe_prompt);
+});
+
+/**
+ * Function to be passed to SpecialPowers.spawn that dispatches a MouseEvent
+ * of a certain type to some element in a subframe.
+ *
+ * @param {String} targetID The ID of the element that will have the event
+ * dispatched on.
+ * @param {String} type The type of MouseEvent.
+ * @returns Promise
+ * @resolves Once the event has been dispatched.
+ */
+async function dispatchMouseEvent(targetID, type) {
+  /* eslint-disable no-undef */
+  let document = content.document;
+  let element = document.getElementById(targetID);
+  let event = document.createEvent("MouseEvent");
+  event.initEvent(type, false, false, content, 0, 1, 1, 1, 1,
+                  false, false, false, false, 0, null);
+  content.windowUtils.dispatchDOMEventViaPresShellForTesting(element, event);
+  /* eslint-enable no-undef */
+}
+</script>
+</body>
+</html>