fix: Replace deprecated tmpnam with mkstemp in test utilities

Replace std::tmpnam() with a safer mkstemp()-based implementation
in daemon_utils_test.cpp and file_logging_test.cpp. The deprecated
tmpnam() function has security vulnerabilities and is not recommended
for modern C++ code.

Changes:
- Add GenerateTempFilePath() helper using mkstemp()
- Replace all tmpnam() calls with the new helper
- Add required headers (unistd.h, stdexcept)
- Improve temporary file path generation security

Author: libraz

tests/utils/daemon_utils_test.cpp

@@ -17,19 +17,37 @@
 #include <cstdio>
 #include <filesystem>
 #include <fstream>
+#include <stdexcept>
 #endif
 
 using namespace mygramdb::utils;
 
 #ifndef _WIN32
 
+namespace {
+/**
+ * @brief Generate a unique temporary file path using mkstemp
+ * @return Temporary file path
+ */
+std::string GenerateTempFilePath() {
+  char temp_template[] = "/tmp/mygramdb_test_XXXXXX";
+  int fd = mkstemp(temp_template);
+  if (fd == -1) {
+    throw std::runtime_error("Failed to create temporary file");
+  }
+  close(fd);
+  unlink(temp_template);  // Remove the file, we just need the path
+  return std::string(temp_template);
+}
+}  // namespace
+
 /**
  * @brief Test that Daemonize() successfully creates a background process
  */
 TEST(DaemonUtilsTest, DaemonizeSuccess) {
   // Create a test file to verify daemon execution
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string test_file = std::string(temp_file) + ".daemon_test";
+  std::string temp_file = GenerateTempFilePath();
+  std::string test_file = temp_file + ".daemon_test";
 
   // Remove if exists
   std::filesystem::remove(test_file);
@@ -81,8 +99,8 @@ TEST(DaemonUtilsTest, DaemonizeSuccess) {
  * @brief Test that daemon process has no controlling terminal
  */
 TEST(DaemonUtilsTest, NoControllingTerminal) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string test_file = std::string(temp_file) + ".ctty_test";
+  std::string temp_file = GenerateTempFilePath();
+  std::string test_file = temp_file + ".ctty_test";
 
   std::filesystem::remove(test_file);
 
@@ -134,8 +152,8 @@ TEST(DaemonUtilsTest, NoControllingTerminal) {
  * @brief Test that daemon process is in a new session
  */
 TEST(DaemonUtilsTest, NewSessionCreated) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string test_file = std::string(temp_file) + ".session_test";
+  std::string temp_file = GenerateTempFilePath();
+  std::string test_file = temp_file + ".session_test";
 
   std::filesystem::remove(test_file);
 
@@ -184,8 +202,8 @@ TEST(DaemonUtilsTest, NewSessionCreated) {
  * @brief Test daemon working directory is root
  */
 TEST(DaemonUtilsTest, WorkingDirectoryIsRoot) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string test_file = std::string(temp_file) + ".cwd_test";
+  std::string temp_file = GenerateTempFilePath();
+  std::string test_file = temp_file + ".cwd_test";
 
   std::filesystem::remove(test_file);
 

tests/utils/file_logging_test.cpp

@@ -6,14 +6,31 @@
 #include <gtest/gtest.h>
 #include <spdlog/sinks/basic_file_sink.h>
 #include <spdlog/spdlog.h>
+#include <unistd.h>
 
 #include <cstdio>
 #include <filesystem>
 #include <fstream>
+#include <stdexcept>
 #include <string>
 
 namespace {
 
+/**
+ * @brief Generate a unique temporary file path using mkstemp
+ * @return Temporary file path
+ */
+std::string GenerateTempFilePath() {
+  char temp_template[] = "/tmp/mygramdb_test_XXXXXX";
+  int fd = mkstemp(temp_template);
+  if (fd == -1) {
+    throw std::runtime_error("Failed to create temporary file");
+  }
+  close(fd);
+  unlink(temp_template);  // Remove the file, we just need the path
+  return std::string(temp_template);
+}
+
 /**
  * @brief Read entire file content
  */
@@ -32,8 +49,8 @@ std::string ReadFileContent(const std::string& filepath) {
  * @brief Test basic file logging
  */
 TEST(FileLoggingTest, BasicFileLogging) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string log_file = std::string(temp_file) + ".log";
+  std::string temp_file = GenerateTempFilePath();
+  std::string log_file = temp_file + ".log";
 
   // Ensure file doesn't exist
   std::filesystem::remove(log_file);
@@ -66,8 +83,8 @@ TEST(FileLoggingTest, BasicFileLogging) {
  * @brief Test file logging with directory creation
  */
 TEST(FileLoggingTest, DirectoryCreation) {
-  const char* temp_dir = std::tmpnam(nullptr);
-  std::string log_dir = std::string(temp_dir) + "_logs";
+  std::string temp_dir = GenerateTempFilePath();
+  std::string log_dir = temp_dir + "_logs";
   std::string log_file = log_dir + "/test.log";
 
   // Ensure directory doesn't exist
@@ -105,8 +122,8 @@ TEST(FileLoggingTest, DirectoryCreation) {
  * @brief Test file logging with multiple messages
  */
 TEST(FileLoggingTest, MultipleMessages) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string log_file = std::string(temp_file) + ".log";
+  std::string temp_file = GenerateTempFilePath();
+  std::string log_file = temp_file + ".log";
 
   std::filesystem::remove(log_file);
 
@@ -141,11 +158,11 @@ TEST(FileLoggingTest, MultipleMessages) {
  * @brief Test file logging with nested directory path
  */
 TEST(FileLoggingTest, NestedDirectoryPath) {
-  const char* temp_base = std::tmpnam(nullptr);
-  std::string log_dir = std::string(temp_base) + "_logs/subdir1/subdir2";
+  std::string temp_base = GenerateTempFilePath();
+  std::string log_dir = temp_base + "_logs/subdir1/subdir2";
   std::string log_file = log_dir + "/nested.log";
 
-  std::filesystem::remove_all(std::string(temp_base) + "_logs");
+  std::filesystem::remove_all(temp_base + "_logs");
 
   try {
     // Create nested directories
@@ -167,7 +184,7 @@ TEST(FileLoggingTest, NestedDirectoryPath) {
 
     // Cleanup
     spdlog::drop("test_logger_nested");
-    std::filesystem::remove_all(std::string(temp_base) + "_logs");
+    std::filesystem::remove_all(temp_base + "_logs");
   } catch (const spdlog::spdlog_ex& ex) {
     FAIL() << "spdlog exception: " << ex.what();
   }
@@ -177,8 +194,8 @@ TEST(FileLoggingTest, NestedDirectoryPath) {
  * @brief Test switching from stdout to file logger
  */
 TEST(FileLoggingTest, SwitchToFileLogger) {
-  const char* temp_file = std::tmpnam(nullptr);
-  std::string log_file = std::string(temp_file) + ".log";
+  std::string temp_file = GenerateTempFilePath();
+  std::string log_file = temp_file + ".log";
 
   std::filesystem::remove(log_file);