Serialize errors as JSON

lib/capybara/webkit/browser.rb

@@ -202,26 +202,12 @@ module Capybara::Webkit
       if result.nil?
         raise NoResponseError, "No response received from the server."
       elsif result != 'ok'
-        case response = read_response
-        when "timeout"
-          raise Timeout::Error, "Request timed out after #{timeout_seconds}"
-        else
-          raise InvalidResponseError, response
-        end
+        raise JSON.parse(read_response)
       end
 
       result
     end
 
-    def timeout_seconds
-      seconds = timeout
-      if seconds > 1
-        "#{seconds} seconds"
-      else
-        "1 second"
-      end
-    end
-
     def read_response
       response_length = @connection.gets.to_i
       if response_length > 0

lib/capybara/webkit/errors.rb

@@ -1,5 +1,8 @@
 module Capybara::Webkit
   class InvalidResponseError < StandardError
+    def self.json_create(o)
+      new(o["message"])
+    end
   end
 
   class NoResponseError < StandardError
@@ -9,5 +12,14 @@ module Capybara::Webkit
   end
 
   class ClickFailed < StandardError
+    def self.json_create(o)
+      new
+    end
+  end
+
+  class TimeoutError < Timeout::Error
+    def self.json_create(o)
+      new(o["message"])
+    end
   end
 end

spec/driver_spec.rb

@@ -342,6 +342,11 @@ describe Capybara::Webkit::Driver do
         to raise_error(Capybara::Webkit::InvalidResponseError, /xpath/i)
     end
 
+    it "raises an error for an invalid xpath query within an element" do
+      expect { driver.find("//body").first.find("totally invalid salad") }.
+        to raise_error(Capybara::Webkit::InvalidResponseError, /xpath/i)
+    end
+
     it "returns an attribute's value" do
       driver.find("//p").first["id"].should == "greeting"
     end
@@ -2059,7 +2064,7 @@ describe Capybara::Webkit::Driver do
 
     it "should raise a timeout error" do
       driver.browser.timeout = 1
-      lambda { visit("/") }.should raise_error(Timeout::Error, "Request timed out after 1 second")
+      lambda { visit("/") }.should raise_error(Timeout::Error, "Request timed out after 1 second(s)")
     end
 
     it "should not raise an error when the timeout is high enough" do

src/Command.cpp

@@ -1,4 +1,5 @@
-#include "SocketCommand.h"
+#include "Command.h"
+#include "ErrorMessage.h"
 
 Command::Command(QObject *parent) : QObject(parent) {
 }
@@ -19,3 +20,6 @@ void Command::emitFinished(bool success, QByteArray message) {
   emit finished(new Response(success, message, this));
 }
 
+void Command::emitFinished(bool success, ErrorMessage *message) {
+  emit finished(new Response(success, message, this));
+}

src/Command.h

@@ -1,10 +1,12 @@
 #ifndef COMMAND_H
 #define COMMAND_H
 
-#include <QObject>
 #include "Response.h"
+#include <QObject>
 #include <QString>
 
+class ErrorMessage;
+
 class Command : public QObject {
   Q_OBJECT
 
@@ -17,6 +19,7 @@ class Command : public QObject {
     void emitFinished(bool success);
     void emitFinished(bool success, QString message);
     void emitFinished(bool success, QByteArray message);
+    void emitFinished(bool success, ErrorMessage *message);
 
   signals:
     void finished(Response *response);

src/Connection.cpp

@@ -6,6 +6,7 @@
 #include "PageLoadingCommand.h"
 #include "TimeoutCommand.h"
 #include "SocketCommand.h"
+#include "ErrorMessage.h"
 
 #include <QTcpSocket>
 
@@ -43,9 +44,8 @@ void Connection::pendingLoadFinished(bool success) {
 void Connection::writePageLoadFailure() {
   m_pageSuccess = true;
   QString message = currentPage()->failureString();
-  Response *response = new Response(false, message, this);
-  writeResponse(response);
-  delete response;
+  Response response(false, new ErrorMessage(message));
+  writeResponse(&response);
 }
 
 void Connection::finishCommand(Response *response) {

src/ErrorMessage.cpp

@@ -0,0 +1,26 @@
+#include "ErrorMessage.h"
+#include "JsonSerializer.h"
+
+ErrorMessage::ErrorMessage(QString message, QObject *parent) : QObject(parent) {
+  m_message = message;
+}
+
+ErrorMessage::ErrorMessage(QString type, QString message, QObject *parent) : QObject(parent) {
+  m_type = type;
+  m_message = message;
+}
+
+QByteArray ErrorMessage::toString() {
+  JsonSerializer serializer;
+
+  QVariantMap map;
+
+  if (m_type.isNull())
+    map["json_class"] = "Capybara::Webkit::InvalidResponseError";
+  else
+    map["json_class"] = m_type;
+
+  map["message"] = m_message;
+
+  return serializer.serialize(map);
+}

src/ErrorMessage.h

@@ -0,0 +1,21 @@
+#ifndef __ERROR_MESSAGE_H
+#define __ERROR_MESSAGE_H
+
+#include <QObject>
+#include <QString>
+#include <QByteArray>
+
+class ErrorMessage : public QObject {
+  Q_OBJECT
+
+  public:
+    ErrorMessage(QString message, QObject *parent = 0);
+    ErrorMessage(QString type, QString message, QObject *parent = 0);
+    QByteArray toString();
+
+  private:
+    QString m_type;
+    QString m_message;
+};
+
+#endif

src/Execute.cpp

@@ -1,6 +1,7 @@
 #include "Execute.h"
 #include "WebPage.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 Execute::Execute(WebPageManager *manager, QStringList &arguments, QObject *parent) : SocketCommand(manager, arguments, parent) {
 }
@@ -11,7 +12,7 @@ void Execute::start() {
   if (result.isValid()) {
     emitFinished(true);
   } else {
-    emitFinished(false, QString("Javascript failed to execute"));
+    emitFinished(false, new ErrorMessage("Javascript failed to execute"));
   }
 }
 

src/Find.cpp

@@ -11,7 +11,7 @@ void Find::start() {
   InvocationResult result = page()->invokeCapybaraFunction("find", arguments());
 
   if (result.hasError())
-    return emitFinished(false, QString("Invalid XPath expression"));
+    return emitFinished(false, result.errorMessage());
 
   QString message;
   message = result.result().toString();

src/FrameFocus.cpp

@@ -2,6 +2,7 @@
 #include "SocketCommand.h"
 #include "WebPage.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 FrameFocus::FrameFocus(WebPageManager *manager, QStringList &arguments, QObject *parent) : SocketCommand(manager, arguments, parent) {
 }
@@ -51,7 +52,7 @@ void FrameFocus::focusId(QString name) {
 
 void FrameFocus::focusParent() {
   if (page()->currentFrame()->parentFrame() == 0) {
-    emitFinished(false, QString("Already at parent frame."));
+    emitFinished(false, new ErrorMessage("Already at parent frame."));
   } else {
     page()->currentFrame()->parentFrame()->setFocus();
     success();
@@ -59,7 +60,7 @@ void FrameFocus::focusParent() {
 }
 
 void FrameFocus::frameNotFound() {
-  emitFinished(false, QString("Unable to locate frame. "));
+  emitFinished(false, new ErrorMessage("Unable to locate frame."));
 }
 
 void FrameFocus::success() {

src/InvocationResult.cpp

@@ -1,4 +1,5 @@
 #include "InvocationResult.h"
+#include "ErrorMessage.h"
 
 InvocationResult::InvocationResult(QVariant result, bool error) {
   m_result = result;
@@ -12,3 +13,17 @@ const QVariant &InvocationResult::result() const {
 bool InvocationResult::hasError() {
   return m_error;
 }
+
+ErrorMessage *InvocationResult::errorMessage() {
+  if (!m_result.canConvert<QVariantMap>())
+    return new ErrorMessage(m_result.toString());
+
+  QVariantMap error = m_result.toMap();
+
+  QString message = error["message"].toString();
+
+  if (error["name"] == "Capybara.ClickFailed")
+    return new ErrorMessage("Capybara::Webkit::ClickFailed", message);
+  else
+    return new ErrorMessage(message);
+}

src/InvocationResult.h

@@ -1,10 +1,13 @@
 #include <QVariant>
 
+class ErrorMessage;
+
 class InvocationResult {
   public:
     InvocationResult(QVariant result, bool error = false);
     const QVariant &result() const;
     bool hasError();
+    ErrorMessage *errorMessage();
 
   private:
     QVariant m_result;

src/JavascriptInvocation.cpp

@@ -17,21 +17,21 @@ QStringList &JavascriptInvocation::arguments() {
   return m_arguments;
 }
 
-QVariantMap JavascriptInvocation::getError() {
+QVariant JavascriptInvocation::getError() {
   return m_error;
 }
 
-void JavascriptInvocation::setError(QVariantMap error) {
+void JavascriptInvocation::setError(QVariant error) {
   m_error = error;
 }
 
 InvocationResult JavascriptInvocation::invoke(QWebFrame *frame) {
   frame->addToJavaScriptWindowObject("CapybaraInvocation", this);
   QVariant result = frame->evaluateJavaScript("Capybara.invoke()");
-  if (getError().isEmpty())
-    return InvocationResult(result);
-  else
+  if (getError().isValid())
     return InvocationResult(getError(), true);
+  else
+    return InvocationResult(result);
 }
 
 bool JavascriptInvocation::click(QWebElement element, int left, int top, int width, int height) {

src/JavascriptInvocation.h

@@ -10,15 +10,15 @@ class JavascriptInvocation : public QObject {
   Q_OBJECT
   Q_PROPERTY(QString functionName READ functionName)
   Q_PROPERTY(QStringList arguments READ arguments)
-  Q_PROPERTY(QVariantMap error READ getError WRITE setError)
+  Q_PROPERTY(QVariant error READ getError WRITE setError)
 
   public:
     JavascriptInvocation(const QString &functionName, const QStringList &arguments, WebPage *page, QObject *parent = 0);
     QString &functionName();
     QStringList &arguments();
     Q_INVOKABLE bool click(QWebElement element, int left, int top, int width, int height);
-    QVariantMap getError();
-    void setError(QVariantMap error);
+    QVariant getError();
+    void setError(QVariant error);
     InvocationResult invoke(QWebFrame *);
 
   private:
@@ -26,6 +26,6 @@ class JavascriptInvocation : public QObject {
     QStringList m_arguments;
     WebPage *m_page;
     void execClick(QPoint mousePos);
-    QVariantMap m_error;
+    QVariant m_error;
 };
 

src/Node.cpp

@@ -12,7 +12,7 @@ void Node::start() {
   InvocationResult result = page()->invokeCapybaraFunction(functionName, functionArguments);
 
   if (result.hasError())
-    return emitFinished(false);
+    return emitFinished(false, result.errorMessage());
 
   QString attributeValue = result.result().toString();
   emitFinished(true, attributeValue);

src/NullCommand.cpp

@@ -1,6 +1,7 @@
 #include "NullCommand.h"
 #include "WebPage.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 NullCommand::NullCommand(QString name, QObject *parent) : Command(parent) {
   m_name = name;
@@ -8,6 +9,6 @@ NullCommand::NullCommand(QString name, QObject *parent) : Command(parent) {
 
 void NullCommand::start() {
   QString failure = QString("[Capybara WebKit] Unknown command: ") + m_name + "\n";
-  emitFinished(false, failure);
+  emitFinished(false, new ErrorMessage(failure));
 }
 

src/PageLoadingCommand.cpp

@@ -2,6 +2,7 @@
 #include "SocketCommand.h"
 #include "WebPage.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 PageLoadingCommand::PageLoadingCommand(Command *command, WebPageManager *manager, QObject *parent) : Command(parent) {
   m_manager = manager;
@@ -30,7 +31,7 @@ void PageLoadingCommand::pendingLoadFinished(bool success) {
         emit finished(m_pendingResponse);
       } else {
         QString message = m_manager->currentPage()->failureString();
-        emitFinished(false, message);
+        emitFinished(false, new ErrorMessage(message));
       }
     }
   }

src/Response.cpp

@@ -1,4 +1,5 @@
 #include "Response.h"
+#include "ErrorMessage.h"
 #include <iostream>
 
 Response::Response(bool success, QString message, QObject *parent) : QObject(parent) {
@@ -11,6 +12,12 @@ Response::Response(bool success, QByteArray message, QObject *parent) : QObject(
   m_message = message;
 }
 
+Response::Response(bool success, ErrorMessage *message, QObject *parent) : QObject(parent) {
+  m_success = success;
+  m_message = message->toString();
+  message->deleteLater();
+}
+
 Response::Response(bool success, QObject *parent) : QObject(parent) {
   m_success = success;
 }

src/Response.h

@@ -5,20 +5,25 @@
 #include <QString>
 #include <QByteArray>
 
+class ErrorMessage;
+
 class Response : public QObject {
   Q_OBJECT
 
   public:
-    Response(bool success, QString message, QObject *parent);
-    Response(bool success, QByteArray message, QObject *parent);
+    Response(bool success, QString message, QObject *parent = 0);
+    Response(bool success, QByteArray message, QObject *parent = 0);
+    Response(bool success, ErrorMessage *message, QObject *parent = 0);
     Response(bool success, QObject *parent);
     bool isSuccess() const;
     QByteArray message() const;
     QString toString() const;
 
+  protected:
+    QByteArray m_message;
+
   private:
     bool m_success;
-    QByteArray m_message;
 };
 
 #endif

src/SetTimeout.cpp

@@ -1,5 +1,6 @@
 #include "SetTimeout.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 SetTimeout::SetTimeout(WebPageManager *manager, QStringList &arguments, QObject *parent) : SocketCommand(manager, arguments, parent) {
 }
@@ -13,7 +14,7 @@ void SetTimeout::start() {
     manager()->setTimeout(timeout);
     emitFinished(true);
   } else {
-    emitFinished(false, QString("Invalid value for timeout"));
+    emitFinished(false, new ErrorMessage("Invalid value for timeout"));
   }
 }
 

src/TimeoutCommand.cpp

@@ -2,6 +2,7 @@
 #include "Command.h"
 #include "WebPageManager.h"
 #include "WebPage.h"
+#include "ErrorMessage.h"
 #include <QTimer>
 #include <QApplication>
 
@@ -45,7 +46,7 @@ void TimeoutCommand::pendingLoadFinished(bool success) {
   } else {
     disconnect(m_timer, SIGNAL(timeout()), this, SLOT(commandTimeout()));
     disconnect(m_manager, SIGNAL(loadStarted()), this, SLOT(pageLoadingFromCommand()));
-    emitFinished(false, m_manager->currentPage()->failureString());
+    emitFinished(false, new ErrorMessage(m_manager->currentPage()->failureString()));
   }
 }
 
@@ -58,7 +59,8 @@ void TimeoutCommand::commandTimeout() {
   disconnect(m_manager, SIGNAL(pageFinished(bool)), this, SLOT(pendingLoadFinished(bool)));
   disconnect(m_command, SIGNAL(finished(Response *)), this, SLOT(commandFinished(Response *)));
   m_manager->currentPage()->triggerAction(QWebPage::Stop);
-  emit finished(new Response(false, QString("timeout"), this));
+  QString message = QString("Request timed out after %1 second(s)").arg(m_manager->getTimeout());
+  emitFinished(false, new ErrorMessage("Capybara::Webkit::TimeoutError", message));
 }
 
 void TimeoutCommand::commandFinished(Response *response) {

src/WindowFocus.cpp

@@ -3,6 +3,7 @@
 #include "WebPage.h"
 #include "CommandFactory.h"
 #include "WebPageManager.h"
+#include "ErrorMessage.h"
 
 WindowFocus::WindowFocus(WebPageManager *manager, QStringList &arguments, QObject *parent) : SocketCommand(manager, arguments, parent) {
 }
@@ -12,7 +13,7 @@ void WindowFocus::start() {
 }
 
 void WindowFocus::windowNotFound() {
-  emitFinished(false, QString("Unable to locate window. "));
+  emitFinished(false, new ErrorMessage("Unable to locate window."));
 }
 
 void WindowFocus::success(WebPage *page) {

src/webkit_server.pro

@@ -57,7 +57,8 @@ HEADERS = \
   SetUrlBlacklist.h \
   NoOpReply.h \
   JsonSerializer.h \
-  InvocationResult.h
+  InvocationResult.h \
+  ErrorMessage.h
 
 SOURCES = \
   Version.cpp \
@@ -116,7 +117,8 @@ SOURCES = \
   SetUrlBlacklist.cpp \
   NoOpReply.cpp \
   JsonSerializer.cpp \
-  InvocationResult.cpp
+  InvocationResult.cpp \
+  ErrorMessage.cpp
 
 RESOURCES = webkit_server.qrc
 QT += network webkit