In chromedriver, do not hang when an alert becomes active during an action.

Prohibit certain actions when an alert is active.
BUG=87679
TEST=none

Review URL: http://codereview.chromium.org/7492016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93983 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 208 insertions, 15 deletions

diff --git a/chrome/browser/automation/automation_provider_observers.cc b/chrome/browser/automation/automation_provider_observers.cc
index 89e3f8a..d1e434f 100644
--- a/chrome/browser/automation/automation_provider_observers.cc
+++ b/chrome/browser/automation/automation_provider_observers.cc
@@ -245,6 +245,8 @@ NavigationNotificationObserver::NavigationNotificationObserver(
   registrar_.Add(this, chrome::NOTIFICATION_AUTH_NEEDED, source);
   registrar_.Add(this, chrome::NOTIFICATION_AUTH_SUPPLIED, source);
   registrar_.Add(this, chrome::NOTIFICATION_AUTH_CANCELLED, source);
+  registrar_.Add(this, chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN,
+                 NotificationService::AllSources());
 
   if (include_current_navigation && controller->tab_contents()->IsLoading())
     navigation_started_ = true;
@@ -296,6 +298,8 @@ void NavigationNotificationObserver::Observe(
     // Respond that authentication is needed.
     navigation_started_ = false;
     ConditionMet(AUTOMATION_MSG_NAVIGATION_AUTH_NEEDED);
+  } else if (type == chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN) {
+    ConditionMet(AUTOMATION_MSG_NAVIGATION_BLOCKED_BY_MODAL_DIALOG);
   } else {
     NOTREACHED();
   }
@@ -1158,6 +1162,8 @@ const int FindInPageNotificationObserver::kFindInPageRequestId = -1;
 DomOperationObserver::DomOperationObserver() {
   registrar_.Add(this, chrome::NOTIFICATION_DOM_OPERATION_RESPONSE,
                  NotificationService::AllSources());
+  registrar_.Add(this, chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN,
+                 NotificationService::AllSources());
 }
 
 DomOperationObserver::~DomOperationObserver() {}
@@ -1165,9 +1171,11 @@ DomOperationObserver::~DomOperationObserver() {}
 void DomOperationObserver::Observe(
     int type, const NotificationSource& source,
     const NotificationDetails& details) {
-  if (chrome::NOTIFICATION_DOM_OPERATION_RESPONSE == type) {
+  if (type == chrome::NOTIFICATION_DOM_OPERATION_RESPONSE) {
     Details<DomOperationNotificationDetails> dom_op_details(details);
     OnDomOperationCompleted(dom_op_details->json());
+  } else if (type == chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN) {
+    OnModalDialogShown();
   }
 }
 
@@ -1198,6 +1206,15 @@ void DomOperationMessageSender::OnDomOperationCompleted(
   delete this;
 }
 
+void DomOperationMessageSender::OnModalDialogShown() {
+  if (automation_ && use_json_interface_) {
+    AutomationJSONReply(automation_, reply_message_.release())
+        .SendError("Could not complete script execution because a modal "
+                       "dialog is active");
+    delete this;
+  }
+}
+
 DocumentPrintedNotificationObserver::DocumentPrintedNotificationObserver(
     AutomationProvider* automation, IPC::Message* reply_message)
     : automation_(automation->AsWeakPtr()),
@@ -1881,8 +1898,7 @@ void PageSnapshotTaker::Start() {
 void PageSnapshotTaker::OnDomOperationCompleted(const std::string& json) {
   int dimension;
   if (!base::StringToInt(json, &dimension)) {
-    LOG(ERROR) << "Could not parse received dimensions: " << json;
-    SendMessage(false);
+    SendMessage(false, "could not parse received dimensions: " + json);
   } else if (!received_width_) {
     received_width_ = true;
     entire_page_size_.set_width(dimension);
@@ -1905,13 +1921,21 @@ void PageSnapshotTaker::OnDomOperationCompleted(const std::string& json) {
   }
 }
 
+void PageSnapshotTaker::OnModalDialogShown() {
+  SendMessage(false, "a modal dialog is active");
+}
+
 void PageSnapshotTaker::OnSnapshotTaken(const SkBitmap& bitmap) {
   base::ThreadRestrictions::ScopedAllowIO allow_io;
   std::vector<unsigned char> png_data;
   gfx::PNGCodec::EncodeBGRASkBitmap(bitmap, true, &png_data);
   int bytes_written = file_util::WriteFile(image_path_,
       reinterpret_cast<char*>(&png_data[0]), png_data.size());
-  SendMessage(bytes_written == static_cast<int>(png_data.size()));
+  bool success = bytes_written == static_cast<int>(png_data.size());
+  std::string error_msg;
+  if (!success)
+    error_msg = "could not write snapshot to disk";
+  SendMessage(success, error_msg);
 }
 
 void PageSnapshotTaker::ExecuteScript(const std::wstring& javascript) {
@@ -1927,14 +1951,15 @@ void PageSnapshotTaker::ExecuteScript(const std::wstring& javascript) {
                                             WideToUTF16Hack(javascript));
 }
 
-void PageSnapshotTaker::SendMessage(bool success) {
+void PageSnapshotTaker::SendMessage(bool success,
+                                    const std::string& error_msg) {
   if (automation_) {
     if (success) {
       AutomationJSONReply(automation_, reply_message_.release())
           .SendSuccess(NULL);
     } else {
       AutomationJSONReply(automation_, reply_message_.release())
-          .SendError("Failed to take snapshot of page");
+          .SendError("Failed to take snapshot of page: " + error_msg);
     }
   }
   delete this;
@@ -2413,7 +2438,12 @@ InputEventAckNotificationObserver::InputEventAckNotificationObserver(
       count_(count) {
   DCHECK(1 <= count);
   registrar_.Add(
-      this, content::NOTIFICATION_RENDER_WIDGET_HOST_DID_RECEIVE_INPUT_EVENT_ACK,
+      this,
+      content::NOTIFICATION_RENDER_WIDGET_HOST_DID_RECEIVE_INPUT_EVENT_ACK,
+      NotificationService::AllSources());
+  registrar_.Add(
+      this,
+      chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN,
       NotificationService::AllSources());
 }
 
@@ -2423,6 +2453,13 @@ void InputEventAckNotificationObserver::Observe(
     int type,
     const NotificationSource& source,
     const NotificationDetails& details) {
+  if (type == chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN) {
+    AutomationJSONReply(automation_,
+                        reply_message_.release()).SendSuccess(NULL);
+    delete this;
+    return;
+  }
+
   Details<int> request_details(details);
   // If the event type matches for |count_| times, replies with a JSON message.
   if (event_type_ == *request_details.ptr()) {
@@ -2443,6 +2480,9 @@ AllTabsStoppedLoadingObserver::AllTabsStoppedLoadingObserver(
     IPC::Message* reply_message)
     : automation_(automation->AsWeakPtr()),
       reply_message_(reply_message) {
+  registrar_.Add(this,
+                 chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN,
+                 NotificationService::AllSources());
   for (BrowserList::const_iterator iter = BrowserList::begin();
        iter != BrowserList::end();
        ++iter) {
@@ -2483,6 +2523,17 @@ void AllTabsStoppedLoadingObserver::OnNoMorePendingLoads(
   CheckIfNoMorePendingLoads();
 }
 
+void AllTabsStoppedLoadingObserver::Observe(
+    int type,
+    const NotificationSource& source,
+    const NotificationDetails& details) {
+  if (!automation_) {
+    AutomationJSONReply(automation_,
+                        reply_message_.release()).SendSuccess(NULL);
+    delete this;
+  }
+}
+
 void AllTabsStoppedLoadingObserver::CheckIfNoMorePendingLoads() {
   if (!automation_) {
     delete this;
@@ -2585,6 +2636,10 @@ DragTargetDropAckNotificationObserver::DragTargetDropAckNotificationObserver(
       this,
       content::NOTIFICATION_RENDER_VIEW_HOST_DID_RECEIVE_DRAG_TARGET_DROP_ACK,
       NotificationService::AllSources());
+  registrar_.Add(
+      this,
+      chrome::NOTIFICATION_APP_MODAL_DIALOG_SHOWN,
+      NotificationService::AllSources());
 }
 
 DragTargetDropAckNotificationObserver::
diff --git a/chrome/browser/automation/automation_provider_observers.h b/chrome/browser/automation/automation_provider_observers.h
index 3f6c390..947518a 100644
--- a/chrome/browser/automation/automation_provider_observers.h
+++ b/chrome/browser/automation/automation_provider_observers.h
@@ -584,9 +584,10 @@ class DomOperationObserver : public NotificationObserver {
 
   virtual void Observe(int type,
                        const NotificationSource& source,
-                       const NotificationDetails& details);
+                       const NotificationDetails& details) OVERRIDE;
 
   virtual void OnDomOperationCompleted(const std::string& json) = 0;
+  virtual void OnModalDialogShown() = 0;
 
  private:
   NotificationRegistrar registrar_;
@@ -603,7 +604,8 @@ class DomOperationMessageSender : public DomOperationObserver {
                                      bool use_json_interface);
   virtual ~DomOperationMessageSender();
 
-  virtual void OnDomOperationCompleted(const std::string& json);
+  virtual void OnDomOperationCompleted(const std::string& json) OVERRIDE;
+  virtual void OnModalDialogShown() OVERRIDE;
 
  private:
   base::WeakPtr<AutomationProvider> automation_;
@@ -1235,7 +1237,8 @@ class PageSnapshotTaker : public DomOperationObserver {
 
  private:
   // Overriden from DomOperationObserver.
-  virtual void OnDomOperationCompleted(const std::string& json);
+  virtual void OnDomOperationCompleted(const std::string& json) OVERRIDE;
+  virtual void OnModalDialogShown() OVERRIDE;
 
   // Called by the ThumbnailGenerator when the requested snapshot has been
   // generated.
@@ -1245,7 +1248,7 @@ class PageSnapshotTaker : public DomOperationObserver {
   void ExecuteScript(const std::wstring& javascript);
 
   // Helper method to send a response back to the client. Deletes this.
-  void SendMessage(bool success);
+  void SendMessage(bool success, const std::string& error_msg);
 
   base::WeakPtr<AutomationProvider> automation_;
   scoped_ptr<IPC::Message> reply_message_;
@@ -1483,15 +1486,21 @@ class InputEventAckNotificationObserver : public NotificationObserver {
 // pending loads. This only waits for tabs that exist at the observer's
 // creation. Will send a message on construction if no tabs are loading
 // currently.
-class AllTabsStoppedLoadingObserver : public TabEventObserver {
+class AllTabsStoppedLoadingObserver : public TabEventObserver,
+                                      public NotificationObserver {
  public:
   AllTabsStoppedLoadingObserver(AutomationProvider* automation,
                                 IPC::Message* reply_message);
   virtual ~AllTabsStoppedLoadingObserver();
 
   // TabEventObserver implementation.
-  virtual void OnFirstPendingLoad(TabContents* tab_contents);
-  virtual void OnNoMorePendingLoads(TabContents* tab_contents);
+  virtual void OnFirstPendingLoad(TabContents* tab_contents) OVERRIDE;
+  virtual void OnNoMorePendingLoads(TabContents* tab_contents) OVERRIDE;
+
+  // NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) OVERRIDE;
 
  private:
   typedef std::set<TabContents*> TabSet;
diff --git a/chrome/browser/automation/automation_util.cc b/chrome/browser/automation/automation_util.cc
index fa6a7b9..1c605f3 100644
--- a/chrome/browser/automation/automation_util.cc
+++ b/chrome/browser/automation/automation_util.cc
@@ -15,6 +15,7 @@
 #include "chrome/browser/automation/automation_provider_json.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "content/browser/browser_thread.h"
@@ -373,4 +374,14 @@ void SetCookieJSON(AutomationProvider* provider,
   reply.SendSuccess(NULL);
 }
 
+bool SendErrorIfModalDialogActive(AutomationProvider* provider,
+                                  IPC::Message* message) {
+  bool active = AppModalDialogQueue::GetInstance()->HasActiveDialog();
+  if (active) {
+    AutomationJSONReply(provider, message).SendError(
+        "Command cannot be performed because a modal dialog is active");
+  }
+  return active;
+}
+
 }  // namespace automation_util
diff --git a/chrome/browser/automation/automation_util.h b/chrome/browser/automation/automation_util.h
index b15cf2a..fb3a3f6 100644
--- a/chrome/browser/automation/automation_util.h
+++ b/chrome/browser/automation/automation_util.h
@@ -72,6 +72,11 @@ void SetCookieJSON(AutomationProvider* provider,
                    base::DictionaryValue* args,
                    IPC::Message* reply_message);
 
+// Sends a JSON error reply if an app modal dialog is active. Returns whether
+// an error reply was sent.
+bool SendErrorIfModalDialogActive(AutomationProvider* provider,
+                                  IPC::Message* message);
+
 }  // namespace automation_util
 
 #endif  // CHROME_BROWSER_AUTOMATION_AUTOMATION_UTIL_H_
diff --git a/chrome/browser/automation/testing_automation_provider.cc b/chrome/browser/automation/testing_automation_provider.cc
index e26268b..745868d 100644
--- a/chrome/browser/automation/testing_automation_provider.cc
+++ b/chrome/browser/automation/testing_automation_provider.cc
@@ -115,6 +115,8 @@
 #include "chrome/browser/download/download_shelf.h"
 #endif
 
+using automation_util::SendErrorIfModalDialogActive;
+
 namespace {
 
 void SendMouseClick(int flags) {
@@ -876,6 +878,9 @@ void TestingAutomationProvider::WindowSimulateKeyPress(
 
 void TestingAutomationProvider::WebkitMouseClick(DictionaryValue* args,
                                                  IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -922,6 +927,9 @@ void TestingAutomationProvider::WebkitMouseClick(DictionaryValue* args,
 
 void TestingAutomationProvider::WebkitMouseMove(
     DictionaryValue* args, IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -945,6 +953,9 @@ void TestingAutomationProvider::WebkitMouseMove(
 
 void TestingAutomationProvider::WebkitMouseDrag(DictionaryValue* args,
                                                 IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -994,6 +1005,9 @@ void TestingAutomationProvider::WebkitMouseDrag(DictionaryValue* args,
 
 void TestingAutomationProvider::WebkitMouseButtonDown(
     DictionaryValue* args, IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -1019,6 +1033,9 @@ void TestingAutomationProvider::WebkitMouseButtonDown(
 
 void TestingAutomationProvider::WebkitMouseButtonUp(
     DictionaryValue* args, IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -1044,6 +1061,9 @@ void TestingAutomationProvider::WebkitMouseButtonUp(
 
 void TestingAutomationProvider::WebkitMouseDoubleClick(
     DictionaryValue* args, IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -1079,6 +1099,9 @@ void TestingAutomationProvider::WebkitMouseDoubleClick(
 
 void TestingAutomationProvider::DragAndDropFilePaths(
     DictionaryValue* args, IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -5187,6 +5210,9 @@ void TestingAutomationProvider::SendWebKeyPressEventAsync(
 void TestingAutomationProvider::SendWebkitKeyEvent(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   NativeWebKeyboardEvent event;
   // In the event of an error, BuildWebKeyEventFromArgs handles telling what
   // went wrong and sending the reply message; if it fails, we just have to
@@ -5209,6 +5235,9 @@ void TestingAutomationProvider::SendWebkitKeyEvent(
 void TestingAutomationProvider::SendOSLevelKeyEventToTab(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   int modifiers, keycode;
   if (!args->GetInteger("keyCode", &keycode)) {
     AutomationJSONReply(this, reply_message)
@@ -5562,6 +5591,11 @@ void TestingAutomationProvider::SetAppLaunchType(
 void TestingAutomationProvider::WaitForAllTabsToStopLoading(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (AppModalDialogQueue::GetInstance()->HasActiveDialog()) {
+    AutomationJSONReply(this, reply_message).SendSuccess(NULL);
+    return;
+  }
+
   // This class will send the message immediately if no tab is loading.
   new AllTabsStoppedLoadingObserver(this, reply_message);
 }
@@ -5617,6 +5651,9 @@ void TestingAutomationProvider::GetIndicesFromTab(
 void TestingAutomationProvider::NavigateToURL(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   int navigation_count;
   std::string url, error;
   Browser* browser;
@@ -5645,6 +5682,9 @@ void TestingAutomationProvider::NavigateToURL(
 void TestingAutomationProvider::ExecuteJavascriptJSON(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   string16 frame_xpath, javascript;
   std::string error;
   TabContents* tab_contents;
@@ -5682,6 +5722,9 @@ void TestingAutomationProvider::ExecuteJavascriptJSON(
 void TestingAutomationProvider::GoForward(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -5703,6 +5746,9 @@ void TestingAutomationProvider::GoForward(
 void TestingAutomationProvider::GoBack(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -5724,6 +5770,9 @@ void TestingAutomationProvider::GoBack(
 void TestingAutomationProvider::ReloadJSON(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
   if (!GetTabFromJSONArgs(args, &tab_contents, &error)) {
@@ -5769,6 +5818,9 @@ void TestingAutomationProvider::GetTabTitleJSON(
 void TestingAutomationProvider::CaptureEntirePageJSON(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   TabContents* tab_contents;
   std::string error;
 
@@ -5871,6 +5923,9 @@ void TestingAutomationProvider::CloseTabJSON(
 void TestingAutomationProvider::ActivateTabJSON(
     DictionaryValue* args,
     IPC::Message* reply_message) {
+  if (SendErrorIfModalDialogActive(this, reply_message))
+    return;
+
   AutomationJSONReply reply(this, reply_message);
   Browser* browser;
   TabContents* tab_contents;
diff --git a/chrome/browser/automation/testing_automation_provider.h b/chrome/browser/automation/testing_automation_provider.h
index 399e798..497c55e 100644
--- a/chrome/browser/automation/testing_automation_provider.h
+++ b/chrome/browser/automation/testing_automation_provider.h
@@ -837,7 +837,7 @@ class TestingAutomationProvider : public AutomationProvider,
                         base::DictionaryValue* args,
                         IPC::Message* reply_message);
 
-  // Waits for all tabs to stop loading.
+  // Waits for all tabs to stop loading or a modal dialog to become active.
   void WaitForAllTabsToStopLoading(base::DictionaryValue* args,
                                    IPC::Message* reply_message);
 
diff --git a/chrome/common/automation_constants.h b/chrome/common/automation_constants.h
index ae7df0c..1b524d1 100644
--- a/chrome/common/automation_constants.h
+++ b/chrome/common/automation_constants.h
@@ -77,6 +77,7 @@ enum AutomationMsg_NavigationResponseValues {
   AUTOMATION_MSG_NAVIGATION_ERROR = 0,
   AUTOMATION_MSG_NAVIGATION_SUCCESS,
   AUTOMATION_MSG_NAVIGATION_AUTH_NEEDED,
+  AUTOMATION_MSG_NAVIGATION_BLOCKED_BY_MODAL_DIALOG,
 };
 
 enum AutomationMsg_ExtensionResponseValues {
diff --git a/chrome/test/webdriver/test/WEBDRIVER_TESTS b/chrome/test/webdriver/test/WEBDRIVER_TESTS
index d95b536..b17d401 100644
--- a/chrome/test/webdriver/test/WEBDRIVER_TESTS
+++ b/chrome/test/webdriver/test/WEBDRIVER_TESTS
@@ -23,6 +23,7 @@
 # features. See bug 71237.
 {
   'all': [
+    'alerts_tests',
     'children_finding_tests',
     # Cookie tests try to set the domain explicitly to 'localhost', which
     # is not allowed.
diff --git a/chrome/test/webdriver/test/alert_on_load.html b/chrome/test/webdriver/test/alert_on_load.html
new file mode 100644
index 0000000..a325163
--- /dev/null
+++ b/chrome/test/webdriver/test/alert_on_load.html
@@ -0,0 +1,7 @@
+<html>
+  <script>
+    window.onload = function() {
+      alert('hi');
+    }
+  </script>
+</html>
diff --git a/chrome/test/webdriver/test/alerts.html b/chrome/test/webdriver/test/alerts.html
new file mode 100644
index 0000000..93fc102
--- /dev/null
+++ b/chrome/test/webdriver/test/alerts.html
@@ -0,0 +1,7 @@
+<html>
+  <body>
+    <input name='onkeypress' type='text' onkeypress='alert("ok")'></input>
+    <input name='onkeyup' type='text' onkeyup='alert("ok")'></input>
+    <input name='normal' type='text'></input>
+  </body>
+</html>
diff --git a/chrome/test/webdriver/test/chromedriver_tests.py b/chrome/test/webdriver/test/chromedriver_tests.py
index 10d1064..49f5311 100644
--- a/chrome/test/webdriver/test/chromedriver_tests.py
+++ b/chrome/test/webdriver/test/chromedriver_tests.py
@@ -735,6 +735,48 @@ class FrameSwitchingTest(ChromeDriverTest):
       self.assertEquals(str(i), driver.current_url.split('?')[-1])
       driver.switch_to_default_content()
 
+class AlertTest(ChromeDriverTest):
+
+  def testAlertOnLoadDoesNotHang(self):
+    driver = self.GetNewDriver()
+    driver.get(GetTestDataUrl() + '/alert_on_load.html')
+    driver.switch_to_alert().accept()
+
+  def testAlertWhenTypingThrows(self):
+    driver = self.GetNewDriver()
+    driver.get(GetTestDataUrl() + '/alerts.html')
+    input_box = driver.find_element_by_name('onkeypress')
+    self.assertRaises(WebDriverException, input_box.send_keys, 'a')
+
+  def testAlertJustAfterTypingDoesNotThrow(self):
+    driver = self.GetNewDriver()
+    driver.get(GetTestDataUrl() + '/alerts.html')
+    driver.find_element_by_name('onkeyup').send_keys('a')
+    driver.switch_to_alert().accept()
+
+  def testAlertOnScriptDoesNotHang(self):
+    driver = self.GetNewDriver()
+    driver.get(GetTestDataUrl() + '/alerts.html')
+    self.assertRaises(WebDriverException, driver.execute_script, 'alert("ok")')
+
+  def testMustHandleAlertFirst(self):
+    driver = self.GetNewDriver()
+    driver.get(GetTestDataUrl() + '/alerts.html')
+    input_box = driver.find_element_by_name('normal')
+    driver.execute_async_script('arguments[0](); window.alert("ok")')
+
+    self.assertRaises(WebDriverException, driver.execute_script, 'a = 1')
+
+    self.assertRaises(WebDriverException, input_box.send_keys, 'abc')
+
+    self.assertRaises(WebDriverException, driver.get,
+                      GetTestDataUrl() + '/test_page.html')
+
+    self.assertRaises(WebDriverException, driver.refresh)
+    self.assertRaises(WebDriverException, driver.back)
+    self.assertRaises(WebDriverException, driver.forward)
+    self.assertRaises(WebDriverException, driver.get_screenshot_as_base64)
+
 
 """Chrome functional test section. All implementation tests of ChromeDriver
 should go above.