Added test struct to create some prerequisites for tests

tests/main_test.cpp

@@ -1,14 +1,31 @@
 #include <sstream>
+#include <filesystem>
 
 #include <gtest/gtest.h> // include your library here
 #include "lib/mylib/MyClass.h"
 
+struct TemporaryDirectoryTestSuite : public testing::Test { // special test structure
+  const std::string dirname = "./gtest_tmp";
+
+  void SetUp() override { // method that is called at the beginning of every test
+    std::filesystem::create_directories(dirname);
+  }
+
+  void TearDown() override { // method that is called at the end of every test
+    std::filesystem::remove_all(dirname);
+  }
+};
+
 std::vector<std::string> SplitString(const std::string& str) {
   std::istringstream iss(str);
 
   return {std::istream_iterator<std::string>(iss), std::istream_iterator<std::string>()};
 }
 
+TEST_F(TemporaryDirectoryTestSuite, InitTest) {
+  ASSERT_TRUE(std::filesystem::is_directory(dirname));
+}
+
 TEST(MyLibUnitTestSuite, BasicTest1) {
   std::ostringstream out;
   MyClass printer(out);