diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/AppController.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/AppController.cpp
index ad25191b..3fc99e2d 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/AppController.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/AppController.cpp
@@ -18,7 +18,6 @@
 
 #include "AppController.h"
 #include "GRPCService.h"
-#include <bridgepp/GRPC/GRPCUtils.h>
 #include <bridgepp/Exception/Exception.h>
 #include "MainWindow.h"
 #include <bridgepp/Log/Log.h>
@@ -68,7 +67,7 @@ void AppController::setMainWindow(MainWindow *mainWindow) {
 //****************************************************************************************************************************************************
 /// \return The main window.
 //****************************************************************************************************************************************************
-MainWindow &AppController::mainWindow() {
+MainWindow &AppController::mainWindow() const {
     if (!mainWindow_) {
         throw Exception("mainWindow has not yet been registered.");
     }
@@ -79,7 +78,7 @@ MainWindow &AppController::mainWindow() {
 //****************************************************************************************************************************************************
 /// \return A reference to the log.
 //****************************************************************************************************************************************************
-bridgepp::Log &AppController::log() {
+bridgepp::Log &AppController::log() const {
     return *log_;
 }
 
@@ -87,7 +86,7 @@ bridgepp::Log &AppController::log() {
 //****************************************************************************************************************************************************
 /// \return A reference to the bridge-gui log.
 //****************************************************************************************************************************************************
-bridgepp::Log &AppController::bridgeGUILog() {
+bridgepp::Log &AppController::bridgeGUILog() const {
     return *bridgeGUILog_;
 }
 
@@ -95,6 +94,6 @@ bridgepp::Log &AppController::bridgeGUILog() {
 //****************************************************************************************************************************************************
 /// \return A reference to the gRPC service.
 //****************************************************************************************************************************************************
-GRPCService &AppController::grpc() {
+GRPCService &AppController::grpc() const {
     return *grpc_;
 }
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/AppController.h b/internal/frontend/bridge-gui/bridge-gui-tester/AppController.h
index 5d15f813..b2e62353 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/AppController.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/AppController.h
@@ -42,10 +42,10 @@ public: // member functions.
     AppController &operator=(AppController const &) = delete; ///< Disabled assignment operator.
     AppController &operator=(AppController &&) = delete; ///< Disabled move assignment operator.
     void setMainWindow(MainWindow *mainWindow); ///< Set the main window.
-    MainWindow &mainWindow(); ///< Return the main window.
-    bridgepp::Log &log(); ///< Return a reference to the log.
-    bridgepp::Log &bridgeGUILog(); ///< Return a reference to the bridge-gui log.
-    GRPCService &grpc(); ///< Return a reference to the gRPC service.
+    MainWindow &mainWindow() const; ///< Return the main window.
+    bridgepp::Log &log() const; ///< Return a reference to the log.
+    bridgepp::Log &bridgeGUILog() const; ///< Return a reference to the bridge-gui log.
+    GRPCService &grpc() const; ///< Return a reference to the gRPC service.
 
 private: // member functions.
     AppController(); ///< Default constructor.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.cpp
index a19e765a..d8813a92 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.cpp
@@ -26,7 +26,7 @@ using namespace grpc;
 
 
 //****************************************************************************************************************************************************
-/// \param[in] The server token expected from gRPC calls
+/// \param[in] serverToken The server token expected from gRPC calls
 //****************************************************************************************************************************************************
 GRPCMetadataProcessor::GRPCMetadataProcessor(QString const &serverToken)
     : serverToken_(serverToken.toStdString()) {
@@ -43,16 +43,16 @@ bool GRPCMetadataProcessor::IsBlocking() const {
 
 
 //****************************************************************************************************************************************************
-/// \param[in] inputMeta
+/// \param authMetadata The authentication metadata.
 /// \return the result of the metadata processing.
 //****************************************************************************************************************************************************
-Status GRPCMetadataProcessor::Process(AuthMetadataProcessor::InputMetadata const &auth_metadata, AuthContext *,
-    AuthMetadataProcessor::OutputMetadata *, AuthMetadataProcessor::OutputMetadata *) {
+Status GRPCMetadataProcessor::Process(InputMetadata const &authMetadata, AuthContext *,
+    OutputMetadata *, OutputMetadata *) {
     try {
-        AuthMetadataProcessor::InputMetadata::const_iterator pathIt = auth_metadata.find(":path");
-        QString const callName = (pathIt == auth_metadata.end()) ? ("unkown gRPC call") : QString::fromLocal8Bit(pathIt->second);
+        const InputMetadata::const_iterator pathIt = authMetadata.find(":path");
+        QString const callName = (pathIt == authMetadata.end()) ? ("unkown gRPC call") : QString::fromLocal8Bit(pathIt->second);
 
-        AuthMetadataProcessor::InputMetadata::size_type const count = auth_metadata.count(grpcMetadataServerTokenKey);
+        AuthMetadataProcessor::InputMetadata::size_type const count = authMetadata.count(grpcMetadataServerTokenKey);
         if (count == 0) {
             throw Exception(QString("Missing server token in gRPC client call '%1'.").arg(callName));
         }
@@ -61,7 +61,7 @@ Status GRPCMetadataProcessor::Process(AuthMetadataProcessor::InputMetadata const
             throw Exception(QString("Several server tokens were provided in gRPC client call '%1'.").arg(callName));
         }
 
-        if (auth_metadata.find(grpcMetadataServerTokenKey)->second != serverToken_) {
+        if (authMetadata.find(grpcMetadataServerTokenKey)->second != serverToken_) {
             throw Exception(QString("Invalid server token provided by gRPC client call '%1'.").arg(callName));
         }
 
@@ -70,7 +70,7 @@ Status GRPCMetadataProcessor::Process(AuthMetadataProcessor::InputMetadata const
     }
     catch (Exception const &e) {
         app().log().error(e.qwhat());
-        return Status(StatusCode::UNAUTHENTICATED, e.qwhat().toStdString());
+        return Status(UNAUTHENTICATED, e.qwhat().toStdString());
     }
 }
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.h
index 8cca8baa..ef7aecd2 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCMetaDataProcessor.h
@@ -35,7 +35,7 @@ public: // member functions.
     GRPCMetadataProcessor &operator=(GRPCMetadataProcessor const &) = delete; ///< Disabled assignment operator.
     GRPCMetadataProcessor &operator=(GRPCMetadataProcessor &&) = delete; ///< Disabled move assignment operator.
     bool IsBlocking() const override; ///< Is the processor blocking?
-    grpc::Status Process(InputMetadata const &auth_metadata, grpc::AuthContext *context, OutputMetadata *consumed_auth_metadata,
+    grpc::Status Process(InputMetadata const &authMetadata, grpc::AuthContext *context, OutputMetadata *consumed_auth_metadata,
         OutputMetadata *response_metadata) override; ///< Process the metadata
 
 private:
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
index d7c0eb7c..1ef2b392 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.cpp
@@ -31,10 +31,10 @@ GRPCQtProxy::GRPCQtProxy()
 //****************************************************************************************************************************************************
 //
 //****************************************************************************************************************************************************
-void GRPCQtProxy::connectSignals() {
+void GRPCQtProxy::connectSignals() const {
     MainWindow &mainWindow = app().mainWindow();
-    SettingsTab &settingsTab = mainWindow.settingsTab();
-    UsersTab &usersTab = mainWindow.usersTab();
+    SettingsTab const &settingsTab = mainWindow.settingsTab();
+    UsersTab const &usersTab = mainWindow.usersTab();
     connect(this, &GRPCQtProxy::delayedEventRequested, &mainWindow, &MainWindow::sendDelayedEvent);
     connect(this, &GRPCQtProxy::setIsAutostartOnReceived, &settingsTab, &SettingsTab::setIsAutostartOn);
     connect(this, &GRPCQtProxy::setIsBetaEnabledReceived, &settingsTab, &SettingsTab::setIsBetaEnabled);
@@ -157,8 +157,8 @@ void GRPCQtProxy::setClientPlatform(QString const &clientPlatform) {
 /// \param[in] useSSLForIMAP The IMAP connexion mode.
 /// \param[in] useSSLForSMTP The IMAP connexion mode.
 //****************************************************************************************************************************************************
-void GRPCQtProxy::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool userSSLForSMTP) {
-    emit setMailServerSettingsReceived(imapPort, smtpPort, useSSLForIMAP, userSSLForSMTP);
+void GRPCQtProxy::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP) {
+    emit setMailServerSettingsReceived(imapPort, smtpPort, useSSLForIMAP, useSSLForSMTP);
 }
 
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
index 9d3ad154..3db7964a 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCQtProxy.h
@@ -36,7 +36,7 @@ public: // member functions.
     GRPCQtProxy &operator=(GRPCQtProxy const &) = delete; ///< Disabled assignment operator.
     GRPCQtProxy &operator=(GRPCQtProxy &&) = delete; ///< Disabled move assignment operator.
 
-    void connectSignals(); // connect the signals to the main window.
+    void connectSignals() const; // connect the signals to the main window.
     void sendDelayedEvent(bridgepp::SPStreamEvent const &event); ///< Sends a delayed stream event.
     void setIsAutostartOn(bool on); ///< Forwards a SetIsAutostartOn call via a Qt signal.
     void setIsBetaEnabled(bool enabled); ///< Forwards a SetIsBetaEnabled call via a Qt signal.
@@ -49,7 +49,7 @@ public: // member functions.
     void exportTLSCertificates(QString const &folderPath); //< Forward an 'ExportTLSCertificates' call via a Qt signal.
     void setIsStreaming(bool isStreaming); ///< Forward a isStreaming internal messages via a Qt signal.
     void setClientPlatform(QString const &clientPlatform); ///< Forward a setClientPlatform call via a Qt signal.
-    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool userSSLForSMTP); ///< Forwards a setMailServerSettings' call via a Qt signal.
+    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP); ///< Forwards a setMailServerSettings' call via a Qt signal.
     void setIsDoHEnabled(bool enabled); ///< Forwards a setIsDoHEnabled call via a Qt signal.
     void setDiskCachePath(QString const &path); ///< Forwards a setDiskCachePath call via a Qt signal.
     void setIsAutomaticUpdateOn(bool on); ///< Forwards a SetIsAutomaticUpdateOn call via a Qt signal.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
index 118e190b..2f9530b9 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.cpp
@@ -50,7 +50,7 @@ void GRPCServerWorker::run() {
         SslServerCredentialsOptions ssl_opts;
         ssl_opts.pem_root_certs = "";
         ssl_opts.pem_key_cert_pairs.push_back(pair);
-        std::shared_ptr<ServerCredentials> credentials = grpc::SslServerCredentials(ssl_opts);
+        std::shared_ptr<ServerCredentials> const credentials = SslServerCredentials(ssl_opts);
 
         GRPCConfig config;
         config.cert = testTLSCert;
@@ -59,8 +59,7 @@ void GRPCServerWorker::run() {
         credentials->SetAuthMetadataProcessor(processor_); // gRPC interceptors are still experimental in C++, so we use AuthMetadataProcessor
         ServerBuilder builder;
         int port = 0; // Port will not be known until ServerBuilder::BuildAndStart() is called
-        bool const useFileSocket = useFileSocketForGRPC();
-        if (useFileSocket) {
+        if (useFileSocketForGRPC()) {
             QString const fileSocketPath = getAvailableFileSocketPath();
             if (fileSocketPath.isEmpty()) {
                 throw Exception("Could not get an available file socket.");
@@ -102,7 +101,7 @@ void GRPCServerWorker::run() {
 //****************************************************************************************************************************************************
 //
 //****************************************************************************************************************************************************
-void GRPCServerWorker::stop() {
+void GRPCServerWorker::stop() const {
     if (server_) {
         server_->Shutdown();
     }
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.h
index 8eef6bac..9092fca7 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCServerWorker.h
@@ -40,7 +40,7 @@ public: // member functions.
     GRPCServerWorker &operator=(GRPCServerWorker &&) = delete; ///< Disabled move assignment operator.
 
     void run() override; ///< Run the worker.
-    void stop();  ///< Stop the gRPC service.
+    void stop() const;  ///< Stop the gRPC service.
 
 private: // data members
     std::unique_ptr<grpc::Server> server_ { nullptr }; ///< The gRPC server.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
index ec465236..9a90027b 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.cpp
@@ -39,7 +39,7 @@ QString const defaultKeychain = "defaultKeychain"; ///< The default keychain.
 //****************************************************************************************************************************************************
 //
 //****************************************************************************************************************************************************
-void GRPCService::connectProxySignals() {
+void GRPCService::connectProxySignals() const {
     qtProxy_.connectSignals();
 }
 
@@ -185,7 +185,7 @@ Status GRPCService::SetIsAllMailVisible(ServerContext *, BoolValue const *reques
 /// \param[out] response The response.
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::IsAllMailVisible(ServerContext *, Empty const *request, BoolValue *response) {
+Status GRPCService::IsAllMailVisible(ServerContext *, Empty const *, BoolValue *response) {
     app().log().debug(__FUNCTION__);
     response->set_value(app().mainWindow().settingsTab().isAllMailVisible());
     return Status::OK;
@@ -409,7 +409,7 @@ Status GRPCService::Login(ServerContext *, LoginRequest const *request, Empty *)
     UsersTab &usersTab = app().mainWindow().usersTab();
     loginUsername_ = QString::fromStdString(request->username());
 
-    SPUser const& user = usersTab.userTable().userWithUsernameOrEmail(QString::fromStdString(request->username()));
+    SPUser const &user = usersTab.userTable().userWithUsernameOrEmail(QString::fromStdString(request->username()));
     if (user) {
         qtProxy_.sendDelayedEvent(newLoginAlreadyLoggedInEvent(user->id()));
         return Status::OK;
@@ -444,7 +444,7 @@ Status GRPCService::Login(ServerContext *, LoginRequest const *request, Empty *)
 //****************************************************************************************************************************************************
 Status GRPCService::Login2FA(ServerContext *, LoginRequest const *request, Empty *) {
     app().log().debug(__FUNCTION__);
-    UsersTab &usersTab = app().mainWindow().usersTab();
+    UsersTab const &usersTab = app().mainWindow().usersTab();
     if (usersTab.nextUserTFAError()) {
         qtProxy_.sendDelayedEvent(newLoginError(LoginErrorType::TFA_ERROR, "2FA Error."));
         return Status::OK;
@@ -469,7 +469,7 @@ Status GRPCService::Login2FA(ServerContext *, LoginRequest const *request, Empty
 //****************************************************************************************************************************************************
 Status GRPCService::Login2Passwords(ServerContext *, LoginRequest const *request, Empty *) {
     app().log().debug(__FUNCTION__);
-    UsersTab &usersTab = app().mainWindow().usersTab();
+    UsersTab const &usersTab = app().mainWindow().usersTab();
 
     if (usersTab.nextUserTwoPasswordsError()) {
         qtProxy_.sendDelayedEvent(newLoginError(LoginErrorType::TWO_PASSWORDS_ERROR, "Two Passwords error."));
@@ -559,12 +559,12 @@ Status GRPCService::DiskCachePath(ServerContext *, Empty const *, StringValue *r
 Status GRPCService::SetDiskCachePath(ServerContext *, StringValue const *path, Empty *) {
     app().log().debug(__FUNCTION__);
 
-    EventsTab &eventsTab = app().mainWindow().eventsTab();
+    EventsTab const &eventsTab = app().mainWindow().eventsTab();
     QString const qPath = QString::fromStdString(path->value());
 
     // we mimic the behaviour of Bridge
     if (!eventsTab.nextCacheChangeWillSucceed()) {
-        qtProxy_.sendDelayedEvent(newDiskCacheErrorEvent(grpc::DiskCacheErrorType(CANT_MOVE_DISK_CACHE_ERROR)));
+        qtProxy_.sendDelayedEvent(newDiskCacheErrorEvent(static_cast<DiskCacheErrorType>(CANT_MOVE_DISK_CACHE_ERROR)));
     } else {
         qtProxy_.setDiskCachePath(qPath);
         qtProxy_.sendDelayedEvent(newDiskCachePathChangedEvent(qPath));
@@ -601,7 +601,7 @@ Status GRPCService::IsDoHEnabled(ServerContext *, Empty const *, BoolValue *resp
 /// \param[in] settings The IMAP/SMTP settings.
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::SetMailServerSettings(::grpc::ServerContext *context, ImapSmtpSettings const *settings, Empty *) {
+Status GRPCService::SetMailServerSettings(ServerContext *, ImapSmtpSettings const *settings, Empty *) {
     app().log().debug(__FUNCTION__);
     qtProxy_.setMailServerSettings(settings->imapport(), settings->smtpport(), settings->usesslforimap(), settings->usesslforsmtp());
     qtProxy_.sendDelayedEvent(newMailServerSettingsChanged(*settings));
@@ -614,9 +614,9 @@ Status GRPCService::SetMailServerSettings(::grpc::ServerContext *context, ImapSm
 /// \param[out] outSettings The settings
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::MailServerSettings(::grpc::ServerContext *, Empty const *, ImapSmtpSettings *outSettings) {
+Status GRPCService::MailServerSettings(ServerContext *, Empty const *, ImapSmtpSettings *outSettings) {
     app().log().debug(__FUNCTION__);
-    SettingsTab &tab = app().mainWindow().settingsTab();
+    SettingsTab const &tab = app().mainWindow().settingsTab();
     outSettings->set_imapport(tab.imapPort());
     outSettings->set_smtpport(tab.smtpPort());
     outSettings->set_usesslforimap(tab.useSSLForIMAP());
@@ -714,8 +714,8 @@ Status GRPCService::GetUserList(ServerContext *, Empty const *, UserListResponse
 //****************************************************************************************************************************************************
 Status GRPCService::GetUser(ServerContext *, StringValue const *request, grpc::User *response) {
     app().log().debug(__FUNCTION__);
-    QString userID = QString::fromStdString(request->value());
-    SPUser user = app().mainWindow().usersTab().userWithID(userID);
+    QString const userID = QString::fromStdString(request->value());
+    SPUser const user = app().mainWindow().usersTab().userWithID(userID);
     if (!user) {
         return Status(NOT_FOUND, QString("user not found %1").arg(userID).toStdString());
     }
@@ -783,14 +783,14 @@ Status GRPCService::ConfigureUserAppleMail(ServerContext *, ConfigureAppleMailRe
 /// \param[in] request The request
 /// \return The status for the call.
 //****************************************************************************************************************************************************
-Status GRPCService::ExportTLSCertificates(ServerContext *, StringValue const *request, Empty *response) {
+Status GRPCService::ExportTLSCertificates(ServerContext *, StringValue const *request, Empty *) {
     app().log().debug(__FUNCTION__);
-    SettingsTab &tab = app().mainWindow().settingsTab();
+    SettingsTab const &tab = app().mainWindow().settingsTab();
     if (!tab.nextTLSCertExportWillSucceed()) {
-        qtProxy_.sendDelayedEvent(newGenericErrorEvent(grpc::TLS_CERT_EXPORT_ERROR));
+        qtProxy_.sendDelayedEvent(newGenericErrorEvent(TLS_CERT_EXPORT_ERROR));
     }
     if (!tab.nextTLSKeyExportWillSucceed()) {
-        qtProxy_.sendDelayedEvent(newGenericErrorEvent(grpc::TLS_KEY_EXPORT_ERROR));
+        qtProxy_.sendDelayedEvent(newGenericErrorEvent(TLS_KEY_EXPORT_ERROR));
     }
     qtProxy_.exportTLSCertificates(QString::fromStdString(request->value()));
     return Status::OK;
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
index a044da4a..511e911b 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/GRPCService.h
@@ -37,7 +37,7 @@ public: // member functions.
     ~GRPCService() override = default; ///< Destructor.
     GRPCService &operator=(GRPCService const &) = delete; ///< Disabled assignment operator.
     GRPCService &operator=(GRPCService &&) = delete; ///< Disabled move assignment operator.
-    void connectProxySignals(); ///< Connect the signals of the Qt Proxy to the GUI components
+    void connectProxySignals() const; ///< Connect the signals of the Qt Proxy to the GUI components
     bool isStreaming() const; ///< Check if the service is currently streaming events.
     grpc::Status CheckTokens(::grpc::ServerContext *context, ::google::protobuf::StringValue const *request, ::google::protobuf::StringValue *response) override;
     grpc::Status AddLogEntry(::grpc::ServerContext *, ::grpc::AddLogEntryRequest const *request, ::google::protobuf::Empty *) override;
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
index 5f795c12..bf197be4 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.cpp
@@ -63,7 +63,7 @@ MainWindow::MainWindow(QWidget *parent)
 //****************************************************************************************************************************************************
 /// \return A reference to the 'General' tab.
 //****************************************************************************************************************************************************
-SettingsTab &MainWindow::settingsTab() {
+SettingsTab &MainWindow::settingsTab() const {
     return *ui_.settingsTab;
 }
 
@@ -96,7 +96,7 @@ KnowledgeBaseTab& MainWindow::knowledgeBaseTab() const {
 /// \param[in] level The log level.
 /// \param[in] message The log message
 //****************************************************************************************************************************************************
-void MainWindow::addLogEntry(bridgepp::Log::Level level, const QString &message) {
+void MainWindow::addLogEntry(bridgepp::Log::Level level, const QString &message) const {
     addEntryToLogEdit(level, message, *ui_.editLog);
 }
 
@@ -105,7 +105,7 @@ void MainWindow::addLogEntry(bridgepp::Log::Level level, const QString &message)
 /// \param[in] level The log level.
 /// \param[in] message The log message
 //****************************************************************************************************************************************************
-void MainWindow::addBridgeGUILogEntry(bridgepp::Log::Level level, const QString &message) {
+void MainWindow::addBridgeGUILogEntry(bridgepp::Log::Level level, const QString &message) const {
     addEntryToLogEdit(level, message, *ui_.editBridgeGUILog);
 }
 
@@ -113,7 +113,7 @@ void MainWindow::addBridgeGUILogEntry(bridgepp::Log::Level level, const QString
 //****************************************************************************************************************************************************
 /// \param[in] event The event.
 //****************************************************************************************************************************************************
-void MainWindow::sendDelayedEvent(SPStreamEvent const &event) {
+void MainWindow::sendDelayedEvent(SPStreamEvent const &event) const {
     QTimer::singleShot(this->eventsTab().eventDelayMs(), [event] { app().grpc().sendEvent(event); });
 }
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.h b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.h
index b50b045e..44ce322c 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/MainWindow.h
@@ -38,17 +38,17 @@ public: // member functions.
     MainWindow &operator=(MainWindow const &) = delete; ///< Disabled assignment operator.
     MainWindow &operator=(MainWindow &&) = delete; ///< Disabled move assignment operator.
 
-    SettingsTab &settingsTab(); ///< Returns a reference the 'Settings' tab.
+    SettingsTab &settingsTab() const; ///< Returns a reference the 'Settings' tab.
     UsersTab &usersTab() const; ///< Returns a reference to the 'Users' tab.
     EventsTab &eventsTab() const; ///< Returns a reference to the 'Events' tab.
     KnowledgeBaseTab &knowledgeBaseTab() const; ///< Returns a reference to the 'Knowledge Base' tab.
 
 public slots:
-    void sendDelayedEvent(bridgepp::SPStreamEvent const &event); ///< Sends a gRPC event after the delay specified in the UI. The call is non blocking.
+    void sendDelayedEvent(bridgepp::SPStreamEvent const &event) const; ///< Sends a gRPC event after the delay specified in the UI. The call is non blocking.
 
 private slots:
-    void addLogEntry(bridgepp::Log::Level level, QString const &message); ///< Add an entry to the log.
-    void addBridgeGUILogEntry(bridgepp::Log::Level level, const QString &message); ///< Add an entry to the log.
+    void addLogEntry(bridgepp::Log::Level level, QString const &message) const; ///< Add an entry to the log.
+    void addBridgeGUILogEntry(bridgepp::Log::Level level, const QString &message) const; ///< Add an entry to the log.
 
 private:
     Ui::MainWindow ui_ {}; ///< The GUI for the window.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.cpp
index 4d664aa7..dafb5d6a 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.cpp
@@ -31,7 +31,7 @@ using namespace bridgepp;
 /// \param[in] edit The edit containing the address.
 /// \param[in] eventGenerator The factory function creating the event.
 //****************************************************************************************************************************************************
-void connectAddressError(QPushButton* button, QLineEdit* edit, bridgepp::SPStreamEvent (*eventGenerator)(QString const&)) {
+void connectAddressError(QPushButton const* button, QLineEdit* edit, SPStreamEvent (*eventGenerator)(QString const&)) {
     QObject::connect(button, &QPushButton::clicked, [edit, eventGenerator]() { app().grpc().sendEvent(eventGenerator(edit->text())); });
 }
 
@@ -77,13 +77,6 @@ qint32 EventsTab::eventDelayMs() const {
 }
 
 
-//****************************************************************************************************************************************************
-//
-//****************************************************************************************************************************************************
-void EventsTab::updateGUIState() {
-}
-
-
 //****************************************************************************************************************************************************
 ///  \return The bug report results
 //****************************************************************************************************************************************************
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.h b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.h
index dd036212..9e69b071 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/EventsTab.h
@@ -45,7 +45,6 @@ public: // member functions.
     EventsTab& operator=(EventsTab&&) = delete; ///< Disabled move assignment operator.
 
     qint32 eventDelayMs() const; ///< Get the delay for sending automatically generated events.
-    void updateGUIState(); ///< Update the GUI state.
     BugReportResult nextBugReportResult() const; ///< Get the value of the 'Next bug report result' combo box.
     bool isPortFree() const; ///< Get the value for the "Is Port Free" check box.
     bool nextCacheChangeWillSucceed() const; ///< Get the value for the 'Next Cache Change will succeed' edit.
@@ -53,7 +52,7 @@ public: // member functions.
     void resetUI() const; ///< Resets the UI.
 
 private: // data members
-    Ui::EventsTab ui_; ///< The UI for the widget.
+    Ui::EventsTab ui_ {}; ///< The UI for the widget.
 };
 
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/KnowledgeBaseTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/KnowledgeBaseTab.cpp
index 6763375c..3147c282 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/KnowledgeBaseTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/KnowledgeBaseTab.cpp
@@ -39,6 +39,7 @@ KnowledgeBaseTab::KnowledgeBaseTab(QWidget* parent)
 
 }
 
+
 //****************************************************************************************************************************************************
 /// \param[in] checkbox The check box.
 /// \param[in] widgets The widgets to conditionally enable.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
index 4538eb29..428cf242 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.cpp
@@ -18,7 +18,6 @@
 
 #include "SettingsTab.h"
 #include "GRPCService.h"
-#include <bridgepp/GRPC/EventFactory.h>
 #include <bridgepp/BridgeUtils.h>
 
 
@@ -47,7 +46,7 @@ SettingsTab::SettingsTab(QWidget *parent)
 //
 //****************************************************************************************************************************************************
 void SettingsTab::updateGUIState() {
-    bool connected = app().grpc().isStreaming();
+    bool const connected = app().grpc().isStreaming();
     for (QWidget *widget: { ui_.groupVersion, ui_.groupGeneral, ui_.groupMail, ui_.groupPaths, ui_.groupCache }) {
         widget->setEnabled(!connected);
     }
@@ -66,7 +65,7 @@ void SettingsTab::setIsStreaming(bool isStreaming) {
 //****************************************************************************************************************************************************
 /// \param[in] clientPlatform The client platform.
 //****************************************************************************************************************************************************
-void SettingsTab::setClientPlatform(QString const &clientPlatform) {
+void SettingsTab::setClientPlatform(QString const &clientPlatform) const {
     ui_.labelClientPlatformValue->setText(clientPlatform);
 }
 
@@ -131,7 +130,7 @@ bool SettingsTab::isAutostartOn() const {
 //****************************************************************************************************************************************************
 /// \param[in] on Should autostart be turned on?
 //****************************************************************************************************************************************************
-void SettingsTab::setIsAutostartOn(bool on) {
+void SettingsTab::setIsAutostartOn(bool on) const {
     ui_.checkAutostart->setChecked(on);
 }
 
@@ -147,7 +146,7 @@ QString SettingsTab::colorSchemeName() const {
 //****************************************************************************************************************************************************
 /// \param[in] name True if the 'Use Dark Theme' check box should be checked.
 //****************************************************************************************************************************************************
-void SettingsTab::setColorSchemeName(QString const &name) {
+void SettingsTab::setColorSchemeName(QString const &name) const {
     ui_.checkDarkTheme->setChecked(name == colorSchemeDark);
 }
 
@@ -163,7 +162,7 @@ bool SettingsTab::isBetaEnabled() const {
 //****************************************************************************************************************************************************
 /// \param[in] enabled The new state for the 'Beta Enabled' check box.
 //****************************************************************************************************************************************************
-void SettingsTab::setIsBetaEnabled(bool enabled) {
+void SettingsTab::setIsBetaEnabled(bool enabled) const {
     ui_.checkBetaEnabled->setChecked(enabled);
 }
 
@@ -179,7 +178,7 @@ bool SettingsTab::isAllMailVisible() const {
 //****************************************************************************************************************************************************
 /// \param[in] visible The new value for the 'All Mail Visible' check box.
 //****************************************************************************************************************************************************
-void SettingsTab::setIsAllMailVisible(bool visible) {
+void SettingsTab::setIsAllMailVisible(bool visible) const {
     ui_.checkAllMailVisible->setChecked(visible);
 }
 
@@ -195,7 +194,7 @@ bool SettingsTab::isTelemetryDisabled() const {
 //****************************************************************************************************************************************************
 /// \param[in] isDisabled The new value for the 'Disable Telemetry' check box.
 //****************************************************************************************************************************************************
-void SettingsTab::setIsTelemetryDisabled(bool isDisabled) {
+void SettingsTab::setIsTelemetryDisabled(bool isDisabled) const {
     ui_.checkIsTelemetryDisabled->setChecked(isDisabled);
 }
 
@@ -249,7 +248,7 @@ QString SettingsTab::landingPageLink() const {
 /// \param[in] includeLogs Are the log included.
 //****************************************************************************************************************************************************
 void SettingsTab::setBugReport(QString const &osType, QString const &osVersion, QString const &emailClient, QString const &address,
-    QString const &description, bool includeLogs) {
+    QString const &description, bool includeLogs) const {
     ui_.editOSType->setText(osType);
     ui_.editOSVersion->setText(osVersion);
     ui_.editEmailClient->setText(emailClient);
@@ -262,7 +261,7 @@ void SettingsTab::setBugReport(QString const &osType, QString const &osVersion,
 //****************************************************************************************************************************************************
 //
 //****************************************************************************************************************************************************
-void SettingsTab::installTLSCertificate() {
+void SettingsTab::installTLSCertificate() const {
     ui_.labelLastTLSCertInstall->setText(QString("Last install: %1").arg(QDateTime::currentDateTime().toString(Qt::ISODateWithMs)));
     ui_.checkTLSCertIsInstalled->setChecked(this->nextTLSCertInstallResult() == TLSCertInstallResult::Success);
 }
@@ -271,7 +270,7 @@ void SettingsTab::installTLSCertificate() {
 //****************************************************************************************************************************************************
 /// \param[in] folderPath The folder path.
 //****************************************************************************************************************************************************
-void SettingsTab::exportTLSCertificates(QString const &folderPath) {
+void SettingsTab::exportTLSCertificates(QString const &folderPath) const {
     ui_.labeLastTLSCertExport->setText(QString("%1 Export to %2").arg(QDateTime::currentDateTime().toString(Qt::ISODateWithMs),folderPath));
 }
 
@@ -288,7 +287,7 @@ bool SettingsTab::isTLSCertificateInstalled() const {
 /// \return The value for the 'Next TLS cert install result'.
 //****************************************************************************************************************************************************
 SettingsTab::TLSCertInstallResult SettingsTab::nextTLSCertInstallResult() const {
-    return TLSCertInstallResult(ui_.comboNextTLSCertInstallResult->currentIndex());
+    return static_cast<TLSCertInstallResult>(ui_.comboNextTLSCertInstallResult->currentIndex());
 }
 
 
@@ -319,7 +318,7 @@ QString SettingsTab::hostname() const {
 //****************************************************************************************************************************************************
 /// \return The value of the IMAP port spin box.
 //****************************************************************************************************************************************************
-qint32 SettingsTab::imapPort() {
+qint32 SettingsTab::imapPort() const {
     return ui_.spinPortIMAP->value();
 }
 
@@ -327,7 +326,7 @@ qint32 SettingsTab::imapPort() {
 //****************************************************************************************************************************************************
 /// \return The value of the SMTP port spin box.
 //****************************************************************************************************************************************************
-qint32 SettingsTab::smtpPort() {
+qint32 SettingsTab::smtpPort() const {
     return ui_.spinPortSMTP->value();
 }
 
@@ -338,7 +337,7 @@ qint32 SettingsTab::smtpPort() {
 /// \param[in] useSSLForIMAP The IMAP connexion mode.
 /// \param[in] useSSLForSMTP The IMAP connexion mode.
 //****************************************************************************************************************************************************
-void SettingsTab::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP) {
+void SettingsTab::setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP) const {
     ui_.spinPortIMAP->setValue(imapPort);
     ui_.spinPortSMTP->setValue(smtpPort);
     ui_.checkUseSSLForIMAP->setChecked(useSSLForIMAP);
@@ -373,7 +372,7 @@ bool SettingsTab::isDoHEnabled() const {
 //****************************************************************************************************************************************************
 /// \param[in] enabled The state of the 'DoH enabled' check box.
 //****************************************************************************************************************************************************
-void SettingsTab::setIsDoHEnabled(bool enabled) {
+void SettingsTab::setIsDoHEnabled(bool enabled) const {
     ui_.checkDoHEnabled->setChecked(enabled);
 }
 
@@ -381,7 +380,7 @@ void SettingsTab::setIsDoHEnabled(bool enabled) {
 //****************************************************************************************************************************************************
 /// \param[in] path The path of the local cache.
 //****************************************************************************************************************************************************
-void SettingsTab::setDiskCachePath(const QString &path) {
+void SettingsTab::setDiskCachePath(const QString &path) const {
     ui_.editDiskCachePath->setText(path);
 }
 
@@ -405,7 +404,7 @@ bool SettingsTab::isAutomaticUpdateOn() const {
 //****************************************************************************************************************************************************
 /// \param[in] on The value for the 'Automatic Update' check.
 //****************************************************************************************************************************************************
-void SettingsTab::setIsAutomaticUpdateOn(bool on) {
+void SettingsTab::setIsAutomaticUpdateOn(bool on) const {
     ui_.checkAutomaticUpdate->setChecked(on);
 }
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
index 8bed7a62..bb4a143c 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/SettingsTab.h
@@ -64,8 +64,8 @@ public: // member functions.
     bool nextTLSCertExportWillSucceed() const;  ///< Get the status of the 'Next TLS Cert export will succeed' check box.
     bool nextTLSKeyExportWillSucceed() const;  ///< Get the status of the 'Next TLS Key export will succeed' check box.
     QString hostname() const; ///< Get the value of the 'Hostname' edit.
-    qint32 imapPort(); ///< Get the value of the IMAP port spin.
-    qint32 smtpPort(); ///< Get the value of the SMTP port spin.
+    qint32 imapPort() const; ///< Get the value of the IMAP port spin.
+    qint32 smtpPort() const; ///< Get the value of the SMTP port spin.
     bool useSSLForSMTP() const; ///< Get the value for the 'Use SSL for SMTP' check box.
     bool useSSLForIMAP() const; ///< Get the value for the 'Use SSL for IMAP' check box.
     bool isDoHEnabled() const; ///< Get the value for the 'DoH Enabled' check box.
@@ -75,20 +75,20 @@ public: // member functions.
 public slots:
     void updateGUIState(); ///< Update the GUI state.
     void setIsStreaming(bool isStreaming); ///< Set the isStreamingEvents value.
-    void setClientPlatform(QString const &clientPlatform); ///< Set the client platform.
-    void setIsAutostartOn(bool on); ///< Set the value for the 'Autostart' check box.
-    void setIsBetaEnabled(bool enabled); ///< Set the value for the 'Beta Enabled' check box.
-    void setIsAllMailVisible(bool visible); ///< Set the value for the 'All Mail Visible' check box.
-    void setIsTelemetryDisabled(bool isDisabled); ///< Set the value for the 'Disable Telemetry' check box.
-    void setColorSchemeName(QString const &name); ///< Set the value for the 'Use Dark Theme' check box.
+    void setClientPlatform(QString const &clientPlatform) const; ///< Set the client platform.
+    void setIsAutostartOn(bool on) const; ///< Set the value for the 'Autostart' check box.
+    void setIsBetaEnabled(bool enabled) const; ///< Set the value for the 'Beta Enabled' check box.
+    void setIsAllMailVisible(bool visible) const; ///< Set the value for the 'All Mail Visible' check box.
+    void setIsTelemetryDisabled(bool isDisabled) const; ///< Set the value for the 'Disable Telemetry' check box.
+    void setColorSchemeName(QString const &name) const; ///< Set the value for the 'Use Dark Theme' check box.
     void setBugReport(QString const &osType, QString const &osVersion, QString const &emailClient, QString const &address, QString const &description,
-        bool includeLogs); ///< Set the content of the bug report box.
-    void installTLSCertificate(); ///< Install the TLS certificate.
-    void exportTLSCertificates(QString const &folderPath); ///< Export the TLS certificates.
-    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP); ///< Change the mail server settings.
-    void setIsDoHEnabled(bool enabled); ///< Set the value for the 'DoH Enabled' check box.
-    void setDiskCachePath(QString const &path); ///< Set the value for the 'Cache On Disk Enabled' check box.
-    void setIsAutomaticUpdateOn(bool on); ///< Set the value for the 'Automatic Update' check box.
+        bool includeLogs) const; ///< Set the content of the bug report box.
+    void installTLSCertificate() const; ///< Install the TLS certificate.
+    void exportTLSCertificates(QString const &folderPath) const; ///< Export the TLS certificates.
+    void setMailServerSettings(qint32 imapPort, qint32 smtpPort, bool useSSLForIMAP, bool useSSLForSMTP) const; ///< Change the mail server settings.
+    void setIsDoHEnabled(bool enabled) const; ///< Set the value for the 'DoH Enabled' check box.
+    void setDiskCachePath(QString const &path) const; ///< Set the value for the 'Cache On Disk Enabled' check box.
+    void setIsAutomaticUpdateOn(bool on) const; ///< Set the value for the 'Automatic Update' check box.
 
 private: // member functions.
     void resetUI(); ///< Reset the widget.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
index fe5fe4ca..2f098a10 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.cpp
@@ -85,7 +85,7 @@ void UsersTab::onAddUserButton() {
 //
 //****************************************************************************************************************************************************
 void UsersTab::onEditUserButton() {
-    int index = selectedIndex();
+    const int index = selectedIndex();
     if ((index < 0) || (index >= users_.userCount())) {
         return;
     }
@@ -110,7 +110,7 @@ void UsersTab::onEditUserButton() {
 //
 //****************************************************************************************************************************************************
 void UsersTab::onRemoveUserButton() {
-    int index = selectedIndex();
+    const int index = selectedIndex();
     if ((index < 0) || (index >= users_.userCount())) {
         return;
     }
@@ -127,7 +127,7 @@ void UsersTab::onRemoveUserButton() {
 //****************************************************************************************************************************************************
 //
 //****************************************************************************************************************************************************
-void UsersTab::onSelectionChanged(QItemSelection, QItemSelection) {
+void UsersTab::onSelectionChanged(QItemSelection const&, QItemSelection const&) {
     this->updateGUIState();
 }
 
@@ -137,7 +137,6 @@ void UsersTab::onSelectionChanged(QItemSelection, QItemSelection) {
 //****************************************************************************************************************************************************
 void UsersTab::onSendUserBadEvent() {
     SPUser const user = selectedUser();
-    int const index = this->selectedIndex();
 
     if (!user) {
         app().log().error(QString("%1 failed. Unkown user.").arg(__FUNCTION__));
@@ -175,8 +174,8 @@ void UsersTab::onSendUsedBytesChangedEvent() {
         app().log().error(QString("%1 failed. User is not connected").arg(__FUNCTION__));
     }
 
-    qint64 const usedBytes = qint64(ui_.spinUsedBytes->value());
-    user->setUsedBytes(usedBytes);
+    auto const usedBytes = static_cast<qint64>(ui_.spinUsedBytes->value());
+    user->setUsedBytes(static_cast<float>(usedBytes));
     users_.touch(index);
 
     GRPCService &grpc = app().grpc();
@@ -224,9 +223,10 @@ void UsersTab::updateGUIState() {
     QSignalBlocker b(ui_.checkSync);
     bool const syncing = user && user->isSyncing();
     ui_.checkSync->setChecked(syncing);
+    // ReSharper disable once CppDFAUnusedValue
     b = QSignalBlocker(ui_.sliderSync);
     ui_.sliderSync->setEnabled(syncing);
-    qint32 const progressPercent = syncing ? qint32(user->syncProgress() * 100.0f) : 0;
+    qint32 const progressPercent = syncing ? static_cast<qint32>(user->syncProgress() * 100.0f) : 0;
     ui_.sliderSync->setValue(progressPercent);
     ui_.labelSync->setText(syncing ? QString("%1%").arg(progressPercent) : "" );
 }
@@ -418,7 +418,7 @@ void UsersTab::processBadEventUserFeedback(QString const &userID, bool doResync)
         return; // we do not do any form of emulation for resync.
     }
 
-    SPUser user = users_.userWithID(userID);
+    SPUser const user = users_.userWithID(userID);
     if (!user) {
         app().log().error(QString("%1(): could not find user with id %1.").arg(__func__, userID));
     }
@@ -464,12 +464,12 @@ void UsersTab::onCheckSyncToggled(bool checked) {
 //****************************************************************************************************************************************************
 void UsersTab::onSliderSyncValueChanged(int value) {
     SPUser const user = this->selectedUser();
-    if ((!user) || (!user->isSyncing()) || user->syncProgress() == value) {
+    if ((!user) || (!user->isSyncing()) || user->syncProgress() == static_cast<float>(value)) {
         return;
     }
 
     double const progress = value / 100.0;
-    user->setSyncProgress(progress);
+    user->setSyncProgress(static_cast<float>(progress));
     app().grpc().sendEvent(newSyncProgressEvent(user->id(), progress, 1, 1));  // we do not simulate elapsed & remaining.
     this->updateGUIState();
 }
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.h b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.h
index f6100c1b..d7a0e69c 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/Tabs/UsersTab.h
@@ -53,14 +53,14 @@ public slots:
     void setUserSplitMode(QString const &userID, bool makeItActive); ///< Slot for the split mode.
     void logoutUser(QString const &userID); ///< slot for the logging out of a user.
     void removeUser(QString const &userID); ///< Slot for the removal of a user.
-    void configureUserAppleMail(QString const &userID, QString const &address); ///< Slot for the configuration of Apple mail.
+static void configureUserAppleMail(QString const &userID, QString const &address); ///< Slot for the configuration of Apple mail.
     void processBadEventUserFeedback(QString const& userID, bool doResync); ///< Slot for the reception of a bad event user feedback.
 
 private slots:
     void onAddUserButton(); ///< Add a user to the user list.
     void onEditUserButton(); ///< Edit the currently selected user.
     void onRemoveUserButton(); ///< Remove the currently selected user.
-    void onSelectionChanged(QItemSelection, QItemSelection); ///< Slot for the change of the selection.
+    void onSelectionChanged(QItemSelection const&, QItemSelection const&); ///< Slot for the change of the selection.
     void onSendUserBadEvent(); ///< Slot for the 'Send Bad Event Error' button.
     void onSendUsedBytesChangedEvent(); ///< Slot for the 'Send Used Bytes Changed Event' button.
     void onSendIMAPLoginFailedEvent(); ///< Slot for the 'Send IMAP Login failure Event' button.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
index 5fbd22a1..fe51aaad 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.cpp
@@ -26,7 +26,7 @@ using namespace bridgepp;
 /// \param[in] user The user.
 /// \param[in] parent The parent widget of the dialog.
 //****************************************************************************************************************************************************
-UserDialog::UserDialog(bridgepp::SPUser &user, QWidget *parent)
+UserDialog::UserDialog(const bridgepp::SPUser &user, QWidget *parent)
     : QDialog(parent)
     , user_(user) {
     ui_.setupUi(this);
@@ -57,8 +57,8 @@ void UserDialog::onOK() {
     user_->setAvatarText(ui_.editAvatarText->text());
     user_->setState(this->state());
     user_->setSplitMode(ui_.checkSplitMode->isChecked());
-    user_->setUsedBytes(float(ui_.spinUsedBytes->value()));
-    user_->setTotalBytes(float(ui_.spinTotalBytes->value()));
+    user_->setUsedBytes(static_cast<float>(ui_.spinUsedBytes->value()));
+    user_->setTotalBytes(static_cast<float>(ui_.spinTotalBytes->value()));
 
     this->accept();
 }
@@ -67,14 +67,14 @@ void UserDialog::onOK() {
 //****************************************************************************************************************************************************
 /// \return The user state  that is currently selected in the dialog.
 //****************************************************************************************************************************************************
-UserState UserDialog::state() {
-    return UserState(ui_.comboState->currentIndex());
+UserState UserDialog::state() const {
+    return static_cast<UserState>(ui_.comboState->currentIndex());
 }
 
 
 //****************************************************************************************************************************************************
 /// \param[in] state The user state to select in the dialog.
 //****************************************************************************************************************************************************
-void UserDialog::setState(UserState state) {
-    ui_.comboState->setCurrentIndex(qint32(state));
+void UserDialog::setState(UserState state) const {
+    ui_.comboState->setCurrentIndex(static_cast<qint32>(state));
 }
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.h b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.h
index c7238207..2d8d6f64 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/UserDialog.h
@@ -30,7 +30,7 @@
 class UserDialog : public QDialog {
 Q_OBJECT
 public: // member functions.
-    UserDialog(bridgepp::SPUser &user, QWidget *parent); ///< Default constructor.
+    UserDialog(const bridgepp::SPUser &user, QWidget *parent); ///< Default constructor.
     UserDialog(UserDialog const &) = delete; ///< Disabled copy-constructor.
     UserDialog(UserDialog &&) = delete; ///< Disabled assignment copy-constructor.
     ~UserDialog() override = default; ///< Destructor.
@@ -38,8 +38,8 @@ public: // member functions.
     UserDialog &operator=(UserDialog &&) = delete; ///< Disabled move assignment operator.
 
 private: // member functions
-    bridgepp::UserState state(); ///< Get the user state selected in the dialog.
-    void setState(bridgepp::UserState state); ///< Set the user state selected in the dialog
+    bridgepp::UserState state() const; ///< Get the user state selected in the dialog.
+    void setState(bridgepp::UserState state) const; ///< Set the user state selected in the dialog
 
 private slots:
     void onOK(); ///< Slot for the OK button.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.cpp
index 95b63e41..9a39cf62 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.cpp
@@ -35,7 +35,7 @@ UserTable::UserTable(QObject *parent)
 /// \return The number of rows in the table.
 //****************************************************************************************************************************************************
 int UserTable::rowCount(QModelIndex const &) const {
-    return users_.size();
+    return static_cast<int>(users_.size());
 }
 
 
@@ -111,7 +111,7 @@ QVariant UserTable::headerData(int section, Qt::Orientation orientation, int rol
 /// \param[in] user The user to add.
 //****************************************************************************************************************************************************
 void UserTable::append(SPUser const &user) {
-    qint32 const count = users_.size();
+    qint32 const count = static_cast<int>(users_.size());
     this->beginInsertRows(QModelIndex(), count, count);
     users_.append(user);
     this->endInsertRows();
@@ -122,7 +122,7 @@ void UserTable::append(SPUser const &user) {
 /// \return The number of users in the table.
 //****************************************************************************************************************************************************
 qint32 UserTable::userCount() const {
-    return users_.count();
+    return static_cast<qint32>(users_.count());
 }
 
 
@@ -141,7 +141,7 @@ bridgepp::SPUser UserTable::userAtIndex(qint32 index) {
 /// \return A null pointer if the user is not in the list.
 //****************************************************************************************************************************************************
 bridgepp::SPUser UserTable::userWithID(QString const &userID) {
-    QList<SPUser>::const_iterator it = std::find_if(users_.constBegin(), users_.constEnd(), [&userID](SPUser const &user) -> bool {
+    QList<SPUser>::const_iterator const it = std::find_if(users_.constBegin(), users_.constEnd(), [&userID](SPUser const &user) -> bool {
         return user->id() == userID;
     });
 
@@ -155,7 +155,7 @@ bridgepp::SPUser UserTable::userWithID(QString const &userID) {
 /// \return A null pointer if the user is not in the list.
 //****************************************************************************************************************************************************
 bridgepp::SPUser UserTable::userWithUsernameOrEmail(QString const &username) {
-    QList<SPUser>::const_iterator it = std::find_if(users_.constBegin(), users_.constEnd(), [&username](SPUser const &user) -> bool {
+    QList<SPUser>::const_iterator const it = std::find_if(users_.constBegin(), users_.constEnd(), [&username](SPUser const &user) -> bool {
         if (user->username().compare(username, Qt::CaseInsensitive) == 0) {
             return true;
         }
@@ -172,7 +172,7 @@ bridgepp::SPUser UserTable::userWithUsernameOrEmail(QString const &username) {
 /// \return -1 if the user could not be found.
 //****************************************************************************************************************************************************
 qint32 UserTable::indexOfUser(QString const &userID) {
-    QList<SPUser>::const_iterator it = std::find_if(users_.constBegin(), users_.constEnd(), [&userID](SPUser const &user) -> bool {
+    QList<SPUser>::const_iterator const it = std::find_if(users_.constBegin(), users_.constEnd(), [&userID](SPUser const &user) -> bool {
         return user->id() == userID;
     });
 
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.h b/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.h
index fc52fed0..ab593e9d 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.h
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/UserTable.h
@@ -33,7 +33,7 @@ public: // member functions.
     explicit UserTable(QObject *parent); ///< Default constructor.
     UserTable(UserTable const &) = delete; ///< Disabled copy-constructor.
     UserTable(UserTable &&) = delete; ///< Disabled assignment copy-constructor.
-    ~UserTable() = default; ///< Destructor.
+    ~UserTable() override = default; ///< Destructor.
     UserTable &operator=(UserTable const &) = delete; ///< Disabled assignment operator.
     UserTable &operator=(UserTable &&) = delete; ///< Disabled move assignment operator.
     qint32 userCount() const; ///< Return the number of users in the table.
diff --git a/internal/frontend/bridge-gui/bridge-gui-tester/main.cpp b/internal/frontend/bridge-gui/bridge-gui-tester/main.cpp
index be65fdfb..170adeb7 100644
--- a/internal/frontend/bridge-gui/bridge-gui-tester/main.cpp
+++ b/internal/frontend/bridge-gui/bridge-gui-tester/main.cpp
@@ -71,7 +71,7 @@ int main(int argc, char **argv) {
             app().log().error(message);
             qApp->exit(EXIT_FAILURE);
         });
-        UPOverseer overseer = std::make_unique<Overseer>(serverWorker, nullptr);
+        UPOverseer const overseer = std::make_unique<Overseer>(serverWorker, nullptr);
         overseer->startWorker(true);
 
         qint32 const exitCode = QApplication::exec();