Implementing driver implementation autodetect in IE driver server

Author: jimevans

cpp/iedriver/BrowserFactory.cpp

@@ -28,6 +28,10 @@
 namespace webdriver {
 
 BrowserFactory::BrowserFactory(void) {
+  // Must be done in the constructor. Do not move to Initialize().
+  this->GetExecutableLocation();
+  this->GetIEVersion();
+  this->GetOSVersion();
 }
 
 BrowserFactory::~BrowserFactory(void) {
@@ -47,9 +51,6 @@ void BrowserFactory::Initialize(BrowserFactorySettings settings) {
   this->browser_command_line_switches_ = StringUtilities::ToWString(settings.browser_command_line_switches);
   this->initial_browser_url_ = StringUtilities::ToWString(settings.initial_browser_url);
 
-  this->GetExecutableLocation();
-  this->GetIEVersion();
-  this->GetOSVersion();
   this->html_getobject_msg_ = ::RegisterWindowMessage(HTML_GETOBJECT_MSG);
 
   // Explicitly load MSAA so we know if it's installed

cpp/iedriver/IESession.cpp

@@ -12,6 +12,7 @@
 // limitations under the License.
 
 #include "IESession.h"
+#include "BrowserFactory.h"
 #include "CommandExecutor.h"
 #include "IECommandExecutor.h"
 #include "IEWebDriverManagerCommandExecutor.h"
@@ -71,7 +72,26 @@ void IESession::Initialize(void* init_params) {
 
   ThreadProcedure thread_proc = &IECommandExecutor::ThreadProc;
   if (this->driver_implementation_ != LegacyImplementation) {
-    thread_proc = &IEWebDriverManagerCommandExecutor::ThreadProc;
+    BrowserFactory factory;
+    int browser_version = factory.browser_version();
+    bool is_component_registered = IEWebDriverManagerCommandExecutor::IsComponentRegistered();
+    if (this->driver_implementation_ == VendorImplementation) {
+      LOG(DEBUG) << "Attempting to use vendor-provided driver implementation per user request";
+      thread_proc = &IEWebDriverManagerCommandExecutor::ThreadProc;
+    } else if (this->driver_implementation_ == AutoDetectImplementation &&
+               browser_version >= 11 &&
+               is_component_registered) {
+      LOG(DEBUG) << "Using vendor-provided driver implementation per autodetection";
+      thread_proc = &IEWebDriverManagerCommandExecutor::ThreadProc;
+    } else {
+      LOG(DEBUG) << "Falling back to legacy driver implementation per autodetection ("
+                 << "detected IE version: " << browser_version
+                 << ", vendor driver install is "
+                 << (is_component_registered ? "" : "not")
+                 << " registered).";
+    }
+  } else {
+    LOG(DEBUG) << "Using legacy driver implementation per user request";
   }
   HANDLE thread_handle = reinterpret_cast<HANDLE>(_beginthreadex(NULL,
                                                                  0,

cpp/iedriver/IEWebDriverManagerCommandExecutor.cpp

@@ -19,6 +19,7 @@
 #include "interactions.h"
 #include "json.h"
 #include "logging.h"
+#include "RegistryUtilities.h"
 #include "StringUtilities.h"
 
 namespace webdriver {
@@ -63,8 +64,11 @@ LRESULT IEWebDriverManagerCommandExecutor::OnCreate(UINT uMsg,
                                   IID_IIEWebDriverManager,
                                   reinterpret_cast<void**>(&this->manager_));
   if (FAILED(hr)) {
-    // TOOD: Handle the case where the COM object is not installed.
+    // If the COM object isn't installed, or there is another error, mark the
+    // session as invalid. In theory, we should only hit this issue if we're
+    // forcing the 
     LOGHR(WARN, hr) << "Could not create instance of class IEWebDriverManager";
+    this->is_valid_ = false;
   }
 
   return 0;
@@ -78,6 +82,7 @@ LRESULT IEWebDriverManagerCommandExecutor::OnDestroy(UINT uMsg,
 
   LOG(DEBUG) << "Posting quit message";
   this->manager_.Release();
+  delete this->factory_;
   ::PostQuitMessage(0);
   LOG(DEBUG) << "Leaving IEWebDriverManagerCommandExecutor::OnDestroy";
   return 0;
@@ -108,7 +113,7 @@ LRESULT IEWebDriverManagerCommandExecutor::OnGetResponseLength(UINT uMsg,
                                                WPARAM wParam,
                                                LPARAM lParam,
                                                BOOL& bHandled) {
-  // Not logging trace entering IEDevChannelCommandExecutor::OnGetResponseLength,
+  // Not logging trace entering IEWebDriverManagerCommandExecutor::OnGetResponseLength,
   // because it is polled repeatedly for a non-zero return value.
   size_t response_length = 0;
   if (!this->is_waiting_) {
@@ -224,21 +229,40 @@ unsigned int WINAPI IEWebDriverManagerCommandExecutor::ThreadProc(LPVOID lpParam
 
 void IEWebDriverManagerCommandExecutor::DispatchCommand() {
   LOG(TRACE) << "Entering IEWebDriverManagerCommandExecutor::DispatchCommand";
-  std::wstring serialized_command = StringUtilities::ToWString(this->current_command_.Serialize());
+  Response actual_response;
+  if (this->current_command_.command_type() == CommandType::NewSession && !this->is_valid_) {
+    // Despite our best efforts, we've attempted to create a new session,
+    // but the IEWebDriverManager COM object could not be instantiated.
+    // The most common case of this would be when the user has attempted
+    // to force the use of the Microsoft driver implementation, but it's
+    // not installed, or is not installed properly. So we have to throw
+    // an error at this point.
+    actual_response.SetErrorResponse(ENOSUCHDRIVER, "Could not create IEWebDriverManager COM object. The most common cause of this is that the driver tool from Microsoft is not installed properly.");
+  } else {
+    std::wstring serialized_command = StringUtilities::ToWString(this->current_command_.Serialize());
 
-  LPWSTR pszResult = nullptr;
+    LPWSTR pszResult = nullptr;
 
-  HRESULT hr = this->manager_->ExecuteCommand((LPWSTR)serialized_command.c_str(), &pszResult);
-  std::wstring result(pszResult);
-  Response actual_response;
-  actual_response.Deserialize(StringUtilities::ToString(result));
+    HRESULT hr = this->manager_->ExecuteCommand((LPWSTR)serialized_command.c_str(), &pszResult);
+    std::wstring result(pszResult);
+    actual_response.Deserialize(StringUtilities::ToString(result));
+    ::CoTaskMemFree(pszResult);
+  }
   this->serialized_response_ = actual_response.Serialize();
-  ::CoTaskMemFree(pszResult);
 
   if (this->current_command_.command_type() == webdriver::CommandType::Close ||
       this->current_command_.command_type() == webdriver::CommandType::Quit) {
     this->is_valid_ = false;
   }
 }
 
+bool IEWebDriverManagerCommandExecutor::IsComponentRegistered() {
+  LPOLESTR webdriver_class_id;
+  ::StringFromCLSID(CLSID_IEWebDriverManager, &webdriver_class_id);
+  std::wstring subkey(L"CLSID\\");
+  subkey.append(webdriver_class_id);
+  ::CoTaskMemFree(webdriver_class_id);
+  return RegistryUtilities::RegistryKeyExists(HKEY_CLASSES_ROOT, subkey);
+}
+
 } // namespace webdriver

cpp/iedriver/IEWebDriverManagerCommandExecutor.h

@@ -57,6 +57,7 @@ class IEWebDriverManagerCommandExecutor : public CWindowImpl<IEWebDriverManagerC
   std::string session_id(void) const { return this->session_id_; }
 
   static unsigned int WINAPI ThreadProc(LPVOID lpParameter);
+  static bool IsComponentRegistered(void);
 
   std::string current_browser_id(void) const { 
     return this->current_browser_id_; 

cpp/iedriver/RegistryUtilities.cpp

@@ -113,4 +113,19 @@ bool RegistryUtilities::GetRegistryValue(const HKEY root_key,
   return value_retrieved;
 }
 
+bool RegistryUtilities::RegistryKeyExists(HKEY root_key,
+                                          const std::wstring& subkey) {
+  HKEY key_handle;
+  long registry_call_result = ::RegOpenKeyEx(root_key,
+                                             subkey.c_str(),
+                                             0,
+                                             KEY_QUERY_VALUE,
+                                             &key_handle);
+  bool result = (ERROR_SUCCESS == registry_call_result);
+  if (result) {
+    ::RegCloseKey(key_handle);
+  }
+  return result;
+}
+
 } // namespace webdriver

cpp/iedriver/RegistryUtilities.h

@@ -27,6 +27,8 @@ class RegistryUtilities {
                                const std::wstring& subkey,
                                const std::wstring& value_name,
                                std::wstring* value);
+  static bool RegistryKeyExists(const HKEY root_key,
+                                const std::wstring& subkey);
 };
 
 } // namespace webdriver