added unit tests using GTest library

test.cpp

@@ -0,0 +1,118 @@
+#include <iostream>
+#include <sstream>
+#include <type_traits>
+#include "String.h"
+#include <gtest/gtest.h>
+
+
+
+TEST(StringTest, defaultConstructible)
+{
+    EXPECT_EQ(true, std::is_default_constructible<String>::value);
+}
+
+TEST(StringTest, constcharConstructible)
+{
+    // is_constructible with multiple template params cannot be passed to macro,
+    // TODO: should open an issue at GTest's GitHub
+    auto value = std::is_constructible<String, const char*>::value;
+    EXPECT_EQ(true, value);
+}
+
+TEST(StringTest, copyConstructible)
+{
+    EXPECT_EQ(true, std::is_copy_constructible<String>::value);
+}
+
+TEST(StringTest, copyAssignable)
+{
+    EXPECT_EQ(true, std::is_copy_assignable<String>::value);
+}
+
+TEST(StringTest, moveConstructible)
+{
+    EXPECT_EQ(true, std::is_move_constructible<String>::value);
+}
+
+TEST(StringTest, moveAssignable)
+{
+    EXPECT_EQ(true, std::is_move_assignable<String>::value);
+}
+
+TEST(StringTest, addable)
+{
+    String str1("cica");
+    String str2("sajt");
+
+    EXPECT_STREQ("cicasajt", (str1+str2).c_str());
+}
+
+TEST(StringTest, plusequalsAddable)
+{
+    String str1("cica");
+    String str2("sajt");
+    str1 += str2;
+
+    EXPECT_STREQ("cicasajt", str1.c_str());
+}
+
+TEST(StringTest, addableChar)
+{
+    String str("cicá");
+
+    EXPECT_STREQ("cicák", (str+'k').c_str());
+}
+
+TEST(StringTest, plusequalsAddableChar)
+{
+    String str("sajto");
+    str+='k';
+
+    EXPECT_STREQ("sajtok", str.c_str());
+}
+
+TEST(StringTest, indexOperatorWorks)
+{
+    String str("cica");
+    char i = 'i';
+
+    EXPECT_EQ(i, str[1]);
+}
+
+TEST(StringTest, resourceSharingWorks)
+{
+    String str1("sajt");
+    String str2 = String("sajt");
+
+    EXPECT_EQ(str1.c_str(), str2.c_str());
+}
+
+struct StreamStringTest : public ::testing::Test
+{
+    std::stringstream _stream;
+};
+
+TEST_F(StreamStringTest, ostreamOperatorWorks)
+{
+    String str("cica");
+    _stream << str;
+
+    EXPECT_STREQ("cica", _stream.str().c_str());
+}
+
+TEST_F(StreamStringTest, istreamOperatorWorks)
+{
+    String str;
+    _stream << "sajt";
+    _stream >> str;
+
+    EXPECT_STREQ("sajt", str.c_str());
+}
+
+
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}