Using Optional<T>

performSearch

// ------ Old

void DOMBackendDispatcher::performSearch(long callId, const InspectorObject& message)
{
    auto protocolErrors = Inspector::Protocol::Array<String>::create();
    RefPtr<InspectorObject> paramsContainer;
    message.getObject(ASCIILiteral("params"), paramsContainer);
    String in_query = BackendDispatcher::getString(paramsContainer.get(), ASCIILiteral("query"), nullptr, protocolErrors.get());
    bool opt_in_nodeIds_valueFound = false;
    RefPtr<Inspector::InspectorArray> opt_in_nodeIds = BackendDispatcher::getArray(paramsContainer.get(), ASCIILiteral("nodeIds"), &opt_in_nodeIds_valueFound, protocolErrors.get());
    if (protocolErrors->length()) {
        String errorMessage = String::format("Some arguments of method '%s' can't be processed", "DOM.performSearch");
        m_backendDispatcher->reportProtocolError(&callId, BackendDispatcher::InvalidParams, errorMessage, WTF::move(protocolErrors));
        return;
    }

#if ENABLE(INSPECTOR_ALTERNATE_DISPATCHERS)
    if (m_alternateDispatcher) {
        m_alternateDispatcher->performSearch(callId, in_query, opt_in_nodeIds_valueFound ? opt_in_nodeIds.get() : nullptr);
        return;
    }
#endif

    ErrorString error;
    Ref<InspectorObject> result = InspectorObject::create();
    String out_searchId;
    int out_resultCount;
    m_agent->performSearch(error, in_query, opt_in_nodeIds_valueFound ? opt_in_nodeIds.get() : nullptr, &out_searchId, &out_resultCount);

    if (!error.length()) {
        result->setString(ASCIILiteral("searchId"), out_searchId);
        result->setInteger(ASCIILiteral("resultCount"), out_resultCount);
    }
    m_backendDispatcher->sendResponse(callId, WTF::move(result), error);
}


// ----- New

void DOMBackendDispatcher::performSearch(long callId, const InspectorObject& parameters, const Inspector::Protocol::Array<String>& protocolErrors)
{
    Optional<String> in_query = BackendDispatcher::getString(parameters, ASCIILiteral("query"), protocolErrors);
    if (protocolErrors.length())
        return;

    if (!in_query) {
        protocolErrors.addItem(String::format("Call to command '%s' must contain required parameter '%s' with type '%s'.", ASCIILiteral("DOM.performSearch"), ASCIILiteral("query"), ASCIILiteral("string")));
        return;
    }

    RefPtr<Inspector::InspectorArray> opt_in_nodeIds = BackendDispatcher::getArray(parameters, ASCIILiteral("nodeIds"), protocolErrors);
    if (protocolErrors->length())
        return;

#if ENABLE(INSPECTOR_ALTERNATE_DISPATCHERS)
    if (m_alternateDispatcher) {
        m_alternateDispatcher->performSearch(callId, in_query, opt_in_nodeIds.valueOr(nullptr));
        return;
    }
#endif

    ErrorString errorString;
    Ref<InspectorObject> result = InspectorObject::create();
    String out_searchId;
    int out_resultCount;
    m_agent->performSearch(errorString, in_query, opt_in_nodeIds.valueOr(nullptr), out_searchId, out_resultCount);

    if (!errorString.length()) {
        result->setString(ASCIILiteral("searchId"), out_searchId);
        result->setInteger(ASCIILiteral("resultCount"), out_resultCount);
    }
    m_backendDispatcher->sendResponse(callId, WTF::move(result), errorString);
}