[Sdk 893, 889] Json exception handling (#70)

* parsing potential issue fixed!

* Json parse exception handling added
using json removed

* added missing namespace

* auto -> explicit datatype

* curl resonse parsing exception handled

* invalid json warning added

Author: ZahidZafar

include/countly.hpp

@@ -17,7 +17,6 @@
 #endif
 
 #include "nlohmann/json.hpp"
-using json = nlohmann::json;
 
 #ifdef _WIN32
 #undef ERROR
@@ -54,7 +53,7 @@ class Countly {
 
 	struct HTTPResponse {
 		bool success;
-		json data;
+		nlohmann::json data;
 	};
 
 	void setSha256(cly::SHA256Function fun);
@@ -120,7 +119,7 @@ class Countly {
 
 	void updateRemoteConfig();
 
-	json getRemoteConfigValue(const std::string& key);
+	nlohmann::json getRemoteConfigValue(const std::string& key);
 
 	void updateRemoteConfigFor(std::string *keys, size_t key_count);
 
@@ -152,15 +151,15 @@ class Countly {
 		template<typename T>
 		void addSegmentation(const std::string& key, T value) {
 			if (object.find("segmentation") == object.end()) {
-				object["segmentation"] = json::object();
+				object["segmentation"] = nlohmann::json::object();
 			}
 
 			object["segmentation"][key] = value;
 		}
 
 		std::string serialize() const;
 	private:
-		json object;
+		nlohmann::json object;
 		bool timer_running;
 		std::chrono::system_clock::time_point timestamp;
 	};
@@ -272,7 +271,7 @@ class Countly {
 
 	std::chrono::system_clock::time_point last_sent_session_request;
 
-	json session_params;
+	nlohmann::json session_params;
 	std::string salt;
 
 	std::unique_ptr<std::thread> thread;
@@ -292,7 +291,7 @@ class Countly {
 #endif
 
 	bool remote_config_enabled = false;
-	json remote_config;
+	nlohmann::json remote_config;
 };
 
 #endif

src/countly.cpp

@@ -12,9 +12,6 @@
 
 #include "countly.hpp"
 
-#include "nlohmann/json.hpp"
-using json = nlohmann::json;
-
 #ifndef COUNTLY_USE_CUSTOM_HTTP
 #ifdef _WIN32
 #include "Windows.h"
@@ -97,7 +94,7 @@ void Countly::setSha256(cly::SHA256Function fun) {
 
 void Countly::setMetrics(const std::string& os, const std::string& os_version, const std::string& device,
 			 const std::string& resolution, const std::string& carrier, const std::string& app_version) {
-	json metrics = json::object();
+	nlohmann::json metrics = nlohmann::json::object();
 
 	if (!os.empty()) {
 		metrics["_os"] = os;
@@ -604,14 +601,14 @@ bool Countly::updateSession() {
 		began_session = true;
 	}
 
-	json events = json::array();
+	nlohmann::json events = nlohmann::json::array();
 	bool no_events;
 
 #ifndef COUNTLY_USE_SQLITE
 	no_events = event_queue.empty();
 	if (!no_events) {
 		for (const auto& event_json: event_queue) {
-			events.push_back(json::parse(event_json));
+			events.push_back(nlohmann::json::parse(event_json));
 		}
 	}
 #else
@@ -641,7 +638,7 @@ bool Countly::updateSession() {
 
 			for (int event_index = 1; event_index < row_count+1; event_index++) {
 				event_id_stream << table[event_index * column_count] << ',';
-				events.push_back(json::parse(table[(event_index * column_count) + 1]));
+				events.push_back(nlohmann::json::parse(table[(event_index * column_count) + 1]));
 			}
 
 			event_id_stream.seekp(-1, event_id_stream.cur);
@@ -938,7 +935,15 @@ Countly::HTTPResponse Countly::sendHTTP(std::string path, std::string data) {
 					} while (n_bytes_available > 0);
 
 					if (!body.empty()) {
-						response.data = json::parse(body);
+						const nlohmann::json& parseResult = nlohmann::json::parse(body, nullptr, false);
+						if (parseResult.is_discarded())
+						{
+							log(Countly::LogLevel::WARNING, "[Countly][sendHTTP] Returned response from the server was not a valid JSON.");
+						}
+						else 
+						{
+							response.data = parseResult;
+						}
 					}
 				}
 			}
@@ -984,8 +989,17 @@ Countly::HTTPResponse Countly::sendHTTP(std::string path, std::string data) {
 			long status_code;
 			curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &status_code);
 			response.success = (status_code >= 200 && status_code < 300);
+
 			if (!body.empty()) {
-				response.data = json::parse(body);
+				const nlohmann::json& parseResult = nlohmann::json::parse(body, nullptr, false);
+				if (parseResult.is_discarded())
+				{
+					log(Countly::LogLevel::WARNING, "[Countly][sendHTTP] Returned response from the server was not a valid JSON.");
+				}
+				else
+				{
+					response.data = parseResult;
+				}
 			}
 		}
 		curl_easy_cleanup(curl);
@@ -1056,9 +1070,9 @@ void Countly::updateRemoteConfig() {
 	}
 }
 
-json Countly::getRemoteConfigValue(const std::string& key) {
+nlohmann::json Countly::getRemoteConfigValue(const std::string& key) {
 	mutex.lock();
-	json value = remote_config[key];
+	nlohmann::json value = remote_config[key];
 	mutex.unlock();
 	return value;
 }
@@ -1071,7 +1085,7 @@ void Countly::updateRemoteConfigFor(std::string *keys, size_t key_count) {
 	};
 
 	{
-		json keys_json = json::array();
+		nlohmann::json keys_json = nlohmann::json::array();
 		for (size_t key_index = 0; key_index < key_count; key_index++) {
 			keys_json.push_back(keys[key_index]);
 		}
@@ -1096,7 +1110,7 @@ void Countly::updateRemoteConfigExcept(std::string *keys, size_t key_count) {
 	};
 
 	{
-		json keys_json = json::array();
+		nlohmann::json keys_json = nlohmann::json::array();
 		for (size_t key_index = 0; key_index < key_count; key_index++) {
 			keys_json.push_back(keys[key_index]);
 		}