Bug 1093153: introduce 'BrowserTestUtils#synthesizeKey', 'BrowserTestUtils#synthesizeComposition' and 'BrowserTestUtils#synthesizeCompositionChange' to allow mochitests to remotely invoke EventUtils' text composition utilities. Changes to EventUtils include 1) removed dependency on the 'navigator' object when 'nsIXULRuntime' is available and 2) make '_getKeyboardEvent' more robust when used in frame scripts. r=Enn

testing/mochitest/BrowserTestUtils/BrowserTestUtils.jsm

@@ -38,6 +38,9 @@ XPCOMUtils.defineLazyModuleGetter(this, "E10SUtils",
 Cu.permitCPOWsInScope(this);
 
 var gSendCharCount = 0;
+var gSynthesizeKeyCount = 0;
+var gSynthesizeCompositionCount = 0;
+var gSynthesizeCompositionChangeCount = 0;
 
 this.BrowserTestUtils = {
   /**
@@ -827,7 +830,7 @@ this.BrowserTestUtils = {
 
   /**
    * Version of EventUtils' `sendChar` function; it will synthesize a keypress
-   * event in a child process and returns a Promise that will result when the
+   * event in a child process and returns a Promise that will resolve when the
    * event was fired. Instead of a Window, a Browser object is required to be
    * passed to this function.
    *
@@ -849,7 +852,7 @@ this.BrowserTestUtils = {
           return;
 
         mm.removeMessageListener("Test:SendCharDone", charMsg);
-        resolve(message.data.sendCharResult);
+        resolve(message.data.result);
       });
 
       mm.sendAsyncMessage("Test:SendChar", {
@@ -859,6 +862,99 @@ this.BrowserTestUtils = {
     });
   },
 
+  /**
+   * Version of EventUtils' `synthesizeKey` function; it will synthesize a key
+   * event in a child process and returns a Promise that will resolve when the
+   * event was fired. Instead of a Window, a Browser object is required to be
+   * passed to this function.
+   *
+   * @param {String} key
+   *        See the documentation available for EventUtils#synthesizeKey.
+   * @param {Object} event
+   *        See the documentation available for EventUtils#synthesizeKey.
+   * @param {Browser} browser
+   *        Browser element, must not be null.
+   *
+   * @returns {Promise}
+   */
+  synthesizeKey(key, event, browser) {
+    return new Promise(resolve => {
+      let seq = ++gSynthesizeKeyCount;
+      let mm = browser.messageManager;
+
+      mm.addMessageListener("Test:SynthesizeKeyDone", function keyMsg(message) {
+        if (message.data.seq != seq)
+          return;
+
+        mm.removeMessageListener("Test:SynthesizeKeyDone", keyMsg);
+        resolve();
+      });
+
+      mm.sendAsyncMessage("Test:SynthesizeKey", { key, event, seq });
+    });
+  },
+
+  /**
+   * Version of EventUtils' `synthesizeComposition` function; it will synthesize
+   * a composition event in a child process and returns a Promise that will
+   * resolve when the event was fired. Instead of a Window, a Browser object is
+   * required to be passed to this function.
+   *
+   * @param {Object} event
+   *        See the documentation available for EventUtils#synthesizeComposition.
+   * @param {Browser} browser
+   *        Browser element, must not be null.
+   *
+   * @returns {Promise}
+   * @resolves False if the composition event could not be synthesized.
+   */
+  synthesizeComposition(event, browser) {
+    return new Promise(resolve => {
+      let seq = ++gSynthesizeCompositionCount;
+      let mm = browser.messageManager;
+
+      mm.addMessageListener("Test:SynthesizeCompositionDone", function compMsg(message) {
+        if (message.data.seq != seq)
+          return;
+
+        mm.removeMessageListener("Test:SynthesizeCompositionDone", compMsg);
+        resolve(message.data.result);
+      });
+
+      mm.sendAsyncMessage("Test:SynthesizeComposition", { event, seq });
+    });
+  },
+
+  /**
+   * Version of EventUtils' `synthesizeCompositionChange` function; it will
+   * synthesize a compositionchange event in a child process and returns a
+   * Promise that will resolve when the event was fired. Instead of a Window, a
+   * Browser object is required to be passed to this function.
+   *
+   * @param {Object} event
+   *        See the documentation available for EventUtils#synthesizeCompositionChange.
+   * @param {Browser} browser
+   *        Browser element, must not be null.
+   *
+   * @returns {Promise}
+   */
+  synthesizeCompositionChange(event, browser) {
+    return new Promise(resolve => {
+      let seq = ++gSynthesizeCompositionChangeCount;
+      let mm = browser.messageManager;
+
+      mm.addMessageListener("Test:SynthesizeCompositionChangeDone", function compMsg(message) {
+        if (message.data.seq != seq)
+          return;
+
+        mm.removeMessageListener("Test:SynthesizeCompositionChangeDone", compMsg);
+        resolve();
+      });
+
+      mm.sendAsyncMessage("Test:SynthesizeCompositionChange", { event, seq });
+    });
+  },
+
   /**
    * Will poll a condition function until it returns true.
    *

testing/mochitest/tests/SimpleTest/AsyncUtilsContent.js

@@ -58,8 +58,20 @@ addMessageListener("Test:SynthesizeMouse", (message) => {
 
 addMessageListener("Test:SendChar", message => {
   let result = EventUtils.sendChar(message.data.char, content);
-  sendAsyncMessage("Test:SendCharDone", {
-    sendCharResult: result,
-    seq: message.data.seq
-  });
+  sendAsyncMessage("Test:SendCharDone", { result, seq: message.data.seq });
+});
+
+addMessageListener("Test:SynthesizeKey", message => {
+  EventUtils.synthesizeKey(message.data.key, message.data.event || {}, content);
+  sendAsyncMessage("Test:SynthesizeKeyDone", { seq: message.data.seq });
+});
+
+addMessageListener("Test:SynthesizeComposition", message => {
+  let result = EventUtils.synthesizeComposition(message.data.event, content);
+  sendAsyncMessage("Test:SynthesizeCompositionDone", { result, seq: message.data.seq });
+});
+
+addMessageListener("Test:SynthesizeCompositionChange", message => {
+  EventUtils.synthesizeCompositionChange(message.data.event, content);
+  sendAsyncMessage("Test:SynthesizeCompositionChangeDone", { seq: message.data.seq });
 });

testing/mochitest/tests/SimpleTest/EventUtils.js

@@ -43,6 +43,24 @@ window.__defineGetter__('_EU_Cu', function() {
   return c.value && !c.writable ? Components.utils : SpecialPowers.Cu;
 });
 
+window.__defineGetter__("_EU_OS", function() {
+  delete this._EU_OS;
+  try {
+    this._EU_OS = Cu.import("resource://gre/modules/AppConstants.jsm", {}).platform;
+  } catch (ex) {
+    this._EU_OS = null;
+  }
+  return this._EU_OS;
+});
+
+function _EU_isMac(aWindow = window) {
+  return window._EU_OS ? window._EU_OS == "macosx" : aWindow.navigator.platform.indexOf("Mac") > -1;
+}
+
+function _EU_isWin(aWindow = window) {
+  return window._EU_OS ? window._EU_OS == "win" : aWindow.navigator.platform.indexOf("Win") > -1;
+}
+
 /**
  * Send a mouse event to the node aTarget (aTarget can be an id, or an
  * actual node) . The "event" passed in to aEvent is just a JavaScript
@@ -237,7 +255,7 @@ function _parseModifiers(aEvent, aWindow = window)
     mval |= nsIDOMWindowUtils.MODIFIER_META;
   }
   if (aEvent.accelKey) {
-    mval |= (navigator.platform.indexOf("Mac") >= 0) ?
+    mval |= _EU_isMac(aWindow) ?
       nsIDOMWindowUtils.MODIFIER_META : nsIDOMWindowUtils.MODIFIER_CONTROL;
   }
   if (aEvent.altGrKey) {
@@ -789,16 +807,13 @@ function _parseNativeModifiers(aModifiers, aWindow = window)
   }
 
   if (aModifiers.accelKey) {
-    modifiers |=
-      (navigator.platform.indexOf("Mac") == 0) ? 0x00004000 : 0x00000400;
+    modifiers |= _EU_isMac(aWindow) ? 0x00004000 : 0x00000400;
   }
   if (aModifiers.accelRightKey) {
-    modifiers |=
-      (navigator.platform.indexOf("Mac") == 0) ? 0x00008000 : 0x00000800;
+    modifiers |= _EU_isMac(aWindow) ? 0x00008000 : 0x00000800;
   }
   if (aModifiers.altGrKey) {
-    modifiers |=
-      (navigator.platform.indexOf("Win") == 0) ? 0x00002800 : 0x00001000;
+    modifiers |= _EU_isWin(aWindow) ? 0x00002800 : 0x00001000;
   }
   return modifiers;
 }
@@ -873,9 +888,9 @@ function synthesizeNativeKey(aKeyboardLayout, aNativeKeyCode, aModifiers,
   }
   var navigator = _getNavigator(aWindow);
   var nativeKeyboardLayout = null;
-  if (navigator.platform.indexOf("Mac") == 0) {
+  if (_EU_isMac(aWindow)) {
     nativeKeyboardLayout = aKeyboardLayout.Mac;
-  } else if (navigator.platform.indexOf("Win") == 0) {
+  } else if (_EU_isWin(aWindow)) {
     nativeKeyboardLayout = aKeyboardLayout.Win;
   }
   if (nativeKeyboardLayout === null) {
@@ -1063,7 +1078,15 @@ function _getTIP(aWindow, aCallback)
 function _getKeyboardEvent(aWindow = window)
 {
   if (typeof KeyboardEvent != "undefined") {
-    return KeyboardEvent;
+    try {
+      // See if the object can be instantiated; sometimes this yields
+      // 'TypeError: can't access dead object' or 'KeyboardEvent is not a constructor'.
+      new KeyboardEvent("", {});
+      return KeyboardEvent;
+    } catch (ex) {}
+  }
+  if (typeof content != "undefined" && ("KeyboardEvent" in content)) {
+    return content.KeyboardEvent;
   }
   return aWindow.KeyboardEvent;
 }
@@ -1282,7 +1305,7 @@ function _emulateToActivateModifiers(aTIP, aKeyEvent, aWindow = window)
       { key: "OS",         attr: "osKey" },
       { key: "Shift",      attr: "shiftKey" },
       { key: "Symbol",     attr: "symbolKey" },
-      { key: (navigator.platform.indexOf("Mac") >= 0) ? "Meta" : "Control",
+      { key: _EU_isMac(aWindow) ? "Meta" : "Control",
                            attr: "accelKey" },
     ],
     lockable: [