diff --git a/main.cpp b/main.cpp
index 71476c6..9fd1c93 100644
--- a/main.cpp
+++ b/main.cpp
@@ -55,7 +55,6 @@ void printMenuItems() {
     std::cout << "Wybierz opcje:" << std::endl;
 }
 
-
 void startDynamicArrayClient() {
     auto *dynamicArrayClient = new DynamicArrayClient();
     dynamicArrayClient->startMainLoop();
diff --git a/src/double_linked_list/DoubleLinkedList.cpp b/src/double_linked_list/DoubleLinkedList.cpp
index 857b1e9..fc9c9e0 100644
--- a/src/double_linked_list/DoubleLinkedList.cpp
+++ b/src/double_linked_list/DoubleLinkedList.cpp
@@ -104,6 +104,7 @@ void DoubleLinkedList::unshift(int data) {
         head->previous = newNode;
         head = newNode;
     }
+    size++;
 }
 
 //COMPLEXITY: O(N)
@@ -157,3 +158,14 @@ int DoubleLinkedList::removeAt(int index) {
     }
     return data;
 }
+
+int DoubleLinkedList::get(int index) {
+    auto *nodePtr = this->head;
+    for (int i = 0; i < index; i++) {
+        nodePtr = nodePtr->next;
+        if (nodePtr == nullptr) {
+            throw std::invalid_argument("Array index out of bound");
+        }
+    }
+    return nodePtr->data;
+}
diff --git a/src/double_linked_list/DoubleLinkedList.h b/src/double_linked_list/DoubleLinkedList.h
index eb4a4a3..462657a 100644
--- a/src/double_linked_list/DoubleLinkedList.h
+++ b/src/double_linked_list/DoubleLinkedList.h
@@ -17,6 +17,8 @@ class DoubleLinkedList {
 
     int shift();
 
+    int get(int index);
+
     int removeAt(int index);
 
     void addAt(int index, int data);
diff --git a/src/dynamic_array/client/DynamicArrayClient.cpp b/src/dynamic_array/client/DynamicArrayClient.cpp
index 4090814..3f9eca8 100644
--- a/src/dynamic_array/client/DynamicArrayClient.cpp
+++ b/src/dynamic_array/client/DynamicArrayClient.cpp
@@ -59,7 +59,6 @@ void DynamicArrayClient::printMenu() {
 }
 
 void DynamicArrayClient::add() {
-    std::cout << "XD";
 }
 
 void DynamicArrayClient::addAtIndex() {
diff --git a/src/heap/MaxHeap.cpp b/src/heap/MaxHeap.cpp
index 40eb5da..81d7fed 100644
--- a/src/heap/MaxHeap.cpp
+++ b/src/heap/MaxHeap.cpp
@@ -23,17 +23,20 @@ MaxHeap::~MaxHeap() {
 }
 
 void MaxHeap::reallocate(int newSize) {
-    if (newSize == 0) {
-        this->size--;
-        return;
+    int *tmpArray = nullptr;
+
+    if (newSize > 0) {
+        tmpArray = new int[newSize];
+        for (int i = 0; i < newSize; i++) {
+            tmpArray[i] = array[i];
+        }
     }
-    int *tmpArray = new int[newSize];
-    for (int i = 0; i < size; i++) {
-        tmpArray[i] = array[i];
+
+    if (this->array != nullptr) {
+        delete[] this->array;
     }
-    int *arrayPtr = array;
+
     this->array = tmpArray;
-    delete arrayPtr;
     this->size = newSize;
 }
 
@@ -81,7 +84,7 @@ void MaxHeap::heapify(int i) {
 
 int MaxHeap::removeMax() {
     if (size == 0) {
-        new std::logic_error("Stack is empty");
+        throw std::logic_error("Heap is empty");
     }
     int data = array[0];
 
@@ -99,3 +102,7 @@ MaxHeap::MaxHeap(int *array, int n) {
     }
 }
 
+int MaxHeap::getSize() {
+    return this->size;
+}
+
diff --git a/src/heap/MaxHeap.h b/src/heap/MaxHeap.h
index 4544448..d4d20ea 100644
--- a/src/heap/MaxHeap.h
+++ b/src/heap/MaxHeap.h
@@ -26,12 +26,14 @@ class MaxHeap {
 
     ~MaxHeap();
 
-    inline int getMax();
+    int getMax();
 
     void insert(int data);
 
     int removeMax();
 
+    int getSize();
+
     void printHeap();
 
 };
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1080da3..2250be9 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,6 +1,6 @@
 project(tests)
 add_subdirectory(googletest-1.13.0)
 
-add_executable(test_run DynamicArrayTests.cpp)
+add_executable(test_run DynamicArrayTests.cpp DoubleLinkedListTest.cpp MaxHeapTest.cpp)
 target_link_libraries(test_run SDIZO_PROJ_1)
 target_link_libraries(test_run gtest gtest_main)
\ No newline at end of file
diff --git a/tests/DoubleLinkedListTest.cpp b/tests/DoubleLinkedListTest.cpp
new file mode 100644
index 0000000..a1f8375
--- /dev/null
+++ b/tests/DoubleLinkedListTest.cpp
@@ -0,0 +1,86 @@
+#include "gtest/gtest.h"
+#include "double_linked_list/DoubleLinkedList.h"
+
+
+class DoubleLinkedListTest : public ::testing::Test {
+
+};
+
+TEST_F(DoubleLinkedListTest, PushAndPop) {
+    DoubleLinkedList list;
+    list.push(1);
+    list.push(2);
+    list.push(3);
+
+    ASSERT_EQ(list.pop(), 3);
+    ASSERT_EQ(list.pop(), 2);
+    ASSERT_EQ(list.pop(), 1);
+}
+
+TEST_F(DoubleLinkedListTest, UnshiftAndShift) {
+    DoubleLinkedList list;
+    list.unshift(1);
+    list.unshift(2);
+    list.unshift(3);
+
+    ASSERT_EQ(list.shift(), 3);
+    ASSERT_EQ(list.shift(), 2);
+    ASSERT_EQ(list.shift(), 1);
+}
+
+TEST_F(DoubleLinkedListTest, AddAtAndRemoveAt) {
+    DoubleLinkedList list;
+    list.addAt(0, 1);
+    list.addAt(1, 3);
+    list.addAt(1, 2);
+
+    ASSERT_EQ(list.removeAt(1), 2);
+    ASSERT_EQ(list.removeAt(1), 3);
+    ASSERT_EQ(list.removeAt(0), 1);
+}
+
+TEST_F(DoubleLinkedListTest, Get) {
+    DoubleLinkedList list;
+    list.push(1);
+    list.push(2);
+    list.push(3);
+
+    ASSERT_EQ(list.get(0), 1);
+    ASSERT_EQ(list.get(1), 2);
+    ASSERT_EQ(list.get(2), 3);
+}
+
+TEST_F(DoubleLinkedListTest, ListEmptyException) {
+    DoubleLinkedList list;
+
+    ASSERT_THROW(list.pop(), std::logic_error);
+    ASSERT_THROW(list.shift(), std::invalid_argument);
+}
+
+TEST_F(DoubleLinkedListTest, IndexOutOfBoundsException) {
+    DoubleLinkedList list;
+    list.push(1);
+    list.push(2);
+    list.push(3);
+
+    ASSERT_THROW(list.get(3), std::invalid_argument);
+    ASSERT_THROW(list.addAt(4, 4), std::invalid_argument);
+    ASSERT_THROW(list.removeAt(3), std::invalid_argument);
+}
+
+TEST_F(DoubleLinkedListTest, PrintListAndPrintReversed) {
+    DoubleLinkedList list;
+    list.push(1);
+    list.push(2);
+    list.push(3);
+
+    testing::internal::CaptureStdout();
+    list.printList();
+    std::string output = testing::internal::GetCapturedStdout();
+    ASSERT_EQ(output, "1 2 3 \n");
+
+    testing::internal::CaptureStdout();
+    list.printReversed();
+    output = testing::internal::GetCapturedStdout();
+    ASSERT_EQ(output, "3 2 1 \n");
+}
diff --git a/tests/MaxHeapTest.cpp b/tests/MaxHeapTest.cpp
new file mode 100644
index 0000000..4e1f9a9
--- /dev/null
+++ b/tests/MaxHeapTest.cpp
@@ -0,0 +1,65 @@
+#include "gtest/gtest.h"
+#include "heap/MaxHeap.h"
+
+class MaxHeapTest : public ::testing::Test {
+
+};
+
+TEST_F(MaxHeapTest, EmptyHeap) {
+    MaxHeap heap;
+    ASSERT_THROW(heap.removeMax(), std::logic_error);
+    ASSERT_EQ(heap.getSize(), 0);
+}
+
+TEST_F(MaxHeapTest, InsertAndRemoveMax) {
+    MaxHeap heap;
+    heap.insert(3);
+    ASSERT_EQ(heap.getMax(), 3);
+    heap.insert(5);
+    ASSERT_EQ(heap.getMax(), 5);
+    heap.insert(1);
+    ASSERT_EQ(heap.getMax(), 5);
+    ASSERT_EQ(heap.removeMax(), 5);
+    ASSERT_EQ(heap.getMax(), 3);
+}
+
+TEST_F(MaxHeapTest, HeapifyArray) {
+    int n = 7;
+    int *inputArray = new int[n]{1, 2, 3, 4, 5, 6, 7};
+    MaxHeap heap(inputArray, n);
+
+    ASSERT_EQ(heap.getMax(), 7);
+    ASSERT_EQ(heap.removeMax(), 7);
+    ASSERT_EQ(heap.getMax(), 6);
+}
+
+TEST_F(MaxHeapTest, HeapifyArrayAndInsert) {
+    int n = 7;
+    int *inputArray = new int[n]{1, 2, 3, 4, 5, 6, 7};
+    MaxHeap heap(inputArray, n);
+    ASSERT_EQ(heap.getMax(), 7);
+    ASSERT_EQ(heap.removeMax(), 7);
+    ASSERT_EQ(heap.getMax(), 6);
+
+    heap.insert(8);
+    ASSERT_EQ(heap.getMax(), 8);
+    ASSERT_EQ(heap.removeMax(), 8);
+    ASSERT_EQ(heap.getMax(), 6);
+}
+
+TEST_F(MaxHeapTest, ReallocationAndSize) {
+    MaxHeap heap;
+    heap.insert(1);
+    heap.insert(2);
+    heap.insert(3);
+    heap.insert(4);
+    heap.insert(5);
+    ASSERT_EQ(heap.getSize(), 5);
+    ASSERT_EQ(heap.getMax(), 5);
+    ASSERT_EQ(heap.removeMax(), 5);
+    ASSERT_EQ(heap.getSize(), 4);
+    ASSERT_EQ(heap.removeMax(), 4);
+    ASSERT_EQ(heap.getSize(), 3);
+}
+
+