diff --git a/test.cpp b/test.cpp
index c8d5eec..09f53c8 100644
--- a/test.cpp
+++ b/test.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <sstream>
 #include <type_traits>
+#include <stdexcept>
 #include "String.h"
 #include <gtest/gtest.h>
 
@@ -8,7 +9,7 @@
 
 TEST(StringTest, defaultConstructible)
 {
-    EXPECT_EQ(true, std::is_default_constructible<String>::value);
+    EXPECT_TRUE(std::is_default_constructible<String>::value);
 }
 
 TEST(StringTest, constcharConstructible)
@@ -16,27 +17,41 @@ 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);
+    EXPECT_TRUE(value);
 }
 
 TEST(StringTest, copyConstructible)
 {
-    EXPECT_EQ(true, std::is_copy_constructible<String>::value);
+    EXPECT_TRUE(std::is_copy_constructible<String>::value);
 }
 
 TEST(StringTest, copyAssignable)
 {
-    EXPECT_EQ(true, std::is_copy_assignable<String>::value);
+    EXPECT_TRUE(std::is_copy_assignable<String>::value);
 }
 
 TEST(StringTest, moveConstructible)
 {
-    EXPECT_EQ(true, std::is_move_constructible<String>::value);
+    EXPECT_TRUE(std::is_move_constructible<String>::value);
 }
 
 TEST(StringTest, moveAssignable)
 {
-    EXPECT_EQ(true, std::is_move_assignable<String>::value);
+    EXPECT_TRUE(std::is_move_assignable<String>::value);
+}
+
+TEST(StringTest, cStrMethodWorks)
+{
+    String str("sajtos cica");
+
+    EXPECT_STREQ("sajtos cica", str.c_str());
+}
+
+TEST(StringTest, uninitializedStringcStrThrows)
+{
+    String str;
+
+    EXPECT_THROW(str.c_str(), std::runtime_error);
 }
 
 TEST(StringTest, addable)
@@ -71,6 +86,22 @@ TEST(StringTest, plusequalsAddableChar)
     EXPECT_STREQ("sajtok", str.c_str());
 }
 
+TEST(StringTest, comparable)
+{
+    String str1("cica");
+    String str2("cica");
+
+    EXPECT_EQ(str1, str2);
+}
+
+TEST(StringTest, uninitializedStringCompareThrows)
+{
+    String str1;
+    String str2;
+
+    EXPECT_THROW(str1 == str2, std::runtime_error);
+}
+
 TEST(StringTest, indexOperatorWorks)
 {
     String str("cica");
@@ -79,6 +110,29 @@ TEST(StringTest, indexOperatorWorks)
     EXPECT_EQ(i, str[1]);
 }
 
+TEST(StringTest, indexoperatorBoundCheckWorks)
+{
+    String str("sajt");
+
+    EXPECT_THROW(str[4], std::out_of_range);
+}
+
+TEST(StringTest, uninitializedStringIndexingThrows)
+{
+    String str;
+
+    EXPECT_THROW(str[0], std::runtime_error);
+}
+
+TEST(StringTest, copyOnWriteWorks)
+{
+    String str1("cica");
+    String str2 = str1;
+    str2[0] = ' ';
+
+    EXPECT_STRNE(str1.c_str(), str2.c_str());
+}
+
 TEST(StringTest, resourceSharingWorks)
 {
     String str1("sajt");