diff --git a/domain-model.md b/domain-model.md
new file mode 100644
index 000000000..4b21b66cc
--- /dev/null
+++ b/domain-model.md
@@ -0,0 +1,27 @@
+
+## Task Class
+
+| Methods                 | Variables            | Scenario                    | Output                |
+|-------------------------|----------------------|-----------------------------|-----------------------|
+|                         | `boolean completed ` |                             |                       |
+|                         | `String name `       |                             |                       |
+| `void completeTask() `  |                      | A task is completed         | Set completed to true |
+| `String getName() `     |                      | Want to fetch a task name   | Return task name      |
+| `boolean getStatus()  ` |                      | Want to fetch a task status | Return task status    |
+|                         |                      |                             |                       |
+
+
+## ToDoList Class
+
+| Methods                                 | Variables                    | Scenario                                           | Output                                                  |
+|-----------------------------------------|------------------------------|----------------------------------------------------|---------------------------------------------------------|
+|                                         | `ArrayList<Task task> list ` |                                                    |                                                         |
+| ` void addTask(Task task) `             |                              | Want to add a task to the ToDo List                | Adds task to list                                       |
+| ` Arraylist<String> seeAllTasks() `     |                              | Want to see all tasks in the list                  | Shows tasks in list                                     |
+| ` void changeStaus(Task task) `         |                              | Want to change status of existing task             | Changes completed variable in chosen task               |
+| ` Arraylist<Task> getCompletedTasks() ` |                              | Want to get only completed tasks                   | Returns all completed tasks                             |
+| ` Arraylist<Task> getInompleteTasks() ` |                              | Want to get only incomplete tasks                  | Returns all incomplete tasks                            |
+| ` Task search(String taskName) `        |                              | Want to search for tasks                           | Searches for and returns task, and informs if not found |
+| ` void removeTask(String taskName) `    |                              | Want to remove a task                              | removes task from list                                  |
+| ` Arraylist<String> alphabeticalA() `   |                              | Want to see tasks in alphabetical ascending order  | Shows tasks in alphabetical ascending order             |
+| ` Arraylist<String> alphabeticalD() `   |                              | Want to see tasks in alphabetical descending order | Shows tasks in alphabetical descending order            |
\ No newline at end of file
diff --git a/src/main/java/com/booleanuk/core/Task.java b/src/main/java/com/booleanuk/core/Task.java
new file mode 100644
index 000000000..97b3ee258
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Task.java
@@ -0,0 +1,24 @@
+package com.booleanuk.core;
+
+public class Task {
+
+    String name;
+    boolean completed;
+
+    public Task(String name){
+        this.name = name;
+        this.completed = false;
+    }
+
+    public String getName(){
+        return this.name;
+    }
+
+    public boolean getStatus(){
+        return this.completed;
+    }
+
+    public void setStatus(boolean status){
+        this.completed = status;
+    }
+}
diff --git a/src/main/java/com/booleanuk/core/ToDoList.java b/src/main/java/com/booleanuk/core/ToDoList.java
new file mode 100644
index 000000000..652020f75
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/ToDoList.java
@@ -0,0 +1,83 @@
+package com.booleanuk.core;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+public class ToDoList {
+
+    ArrayList<Task> tasks = new ArrayList<>();
+
+    public void addTask(Task task){
+        if (!tasks.contains(task)){
+            tasks.add(task);
+        }
+    }
+
+    public void removeTask(String taskName){
+        tasks.removeIf(task -> task.getName().equals(taskName));
+    }
+
+    public void changeStatus(Task task, boolean completed){
+        if (tasks.contains(task)){
+            task.setStatus(completed);
+        }
+    }
+
+    public ArrayList<String> seeAllTasks(){
+        ArrayList<String> showTasks = new ArrayList<>();
+        for (int i = 0; i < tasks.size(); i++){
+            showTasks.add(i, tasks.get(i).name);
+        }
+        return showTasks;
+    }
+
+    public ArrayList<Task> getCompletedTasks(){
+        ArrayList<Task> completedTasks = new ArrayList<>();
+        for (Task task : tasks){
+            if (task.completed){
+                completedTasks.add(task);
+            }
+        }
+        return completedTasks;
+    }
+
+    public ArrayList<Task> getIncompleteTasks(){
+        ArrayList<Task> incompleteTasks = new ArrayList<>();
+        for (Task task : tasks){
+            if (!task.completed){
+                incompleteTasks.add(task);
+            }
+        }
+        return incompleteTasks;
+    }
+
+    public Task search(String taskName){
+        for (Task task : tasks){
+            if (task.name.equals(taskName)){
+                return task;
+            }
+        }
+        System.out.println("The task was not found or does not exist!");
+        return null;
+    }
+
+    public ArrayList<String> alphabeticalA(){
+        ArrayList<String> alphabeticalAscending = new ArrayList<>();
+        for (Task task : tasks){
+            alphabeticalAscending.add(task.name);
+        }
+        Collections.sort(alphabeticalAscending);
+        return alphabeticalAscending;
+    }
+
+    public ArrayList<String> alphabeticalD(){
+        ArrayList<String> alphabeticalDescending = new ArrayList<>();
+        for (Task task : tasks){
+            alphabeticalDescending.add(task.name);
+        }
+        Collections.sort(alphabeticalDescending);
+        Collections.reverse(alphabeticalDescending);
+        return alphabeticalDescending;
+    }
+
+}
diff --git a/src/main/java/com/booleanuk/core/TodoList.java b/src/main/java/com/booleanuk/core/TodoList.java
deleted file mode 100644
index 675adaf0b..000000000
--- a/src/main/java/com/booleanuk/core/TodoList.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package com.booleanuk.core;
-
-public class TodoList {
-
-}
diff --git a/src/main/java/com/booleanuk/extension/Task.java b/src/main/java/com/booleanuk/extension/Task.java
new file mode 100644
index 000000000..688dff701
--- /dev/null
+++ b/src/main/java/com/booleanuk/extension/Task.java
@@ -0,0 +1,37 @@
+package com.booleanuk.extension;
+
+public class Task {
+
+    private static int counter = 0;
+    private final int id;
+    private String name;
+    private boolean completed;
+
+    public Task(String name){
+        this.name = name;
+        this.completed = false;
+        this.id = counter += 1;
+    }
+
+    public int getId(){
+        return this.id;
+    }
+
+    public String getName(){
+        return this.name;
+    }
+
+    public void changeName(String newName){
+        this.name = newName;
+    }
+
+    public boolean getStatus(){
+        return this.completed;
+    }
+
+    public void setStatus(boolean status){
+        this.completed = status;
+    }
+
+
+}
diff --git a/src/main/java/com/booleanuk/extension/ToDoList.java b/src/main/java/com/booleanuk/extension/ToDoList.java
new file mode 100644
index 000000000..c132ffee1
--- /dev/null
+++ b/src/main/java/com/booleanuk/extension/ToDoList.java
@@ -0,0 +1,104 @@
+package com.booleanuk.extension;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+public class ToDoList {
+
+    ArrayList<Task> tasks = new ArrayList<>();
+
+    public Task getTask(int id){
+        for (Task task : tasks){
+            if (task.getId() == id){
+                return task;
+            }
+        }
+        System.out.println("No task with this ID!");
+        return null;
+    }
+
+    public void updateName(int id, String newName){
+        for (Task task : tasks){
+            if (task.getId() == id){
+                task.changeName(newName);
+            }
+        }
+        System.out.println("No task with given ID!");
+    }
+
+    public void addTask(Task task){
+        if (!tasks.contains(task)){
+            tasks.add(task);
+        }
+    }
+
+    public void removeTask(String taskName){
+        tasks.removeIf(task -> task.getName().equals(taskName));
+    }
+
+    public void changeStatus(int id, boolean completed){
+        for (Task task : tasks){
+            if (task.getId() == id){
+                task.setStatus(completed);
+            }
+        }
+    }
+
+    public ArrayList<String> seeAllTasks(){
+        ArrayList<String> showTasks = new ArrayList<>();
+        for (int i = 0; i < tasks.size(); i++){
+            showTasks.add(i, tasks.get(i).getName());
+        }
+        return showTasks;
+    }
+
+    public ArrayList<Task> getCompletedTasks(){
+        ArrayList<Task> completedTasks = new ArrayList<>();
+        for (Task task : tasks){
+            if (task.getStatus()){
+                completedTasks.add(task);
+            }
+        }
+        return completedTasks;
+    }
+
+    public ArrayList<Task> getIncompleteTasks(){
+        ArrayList<Task> incompleteTasks = new ArrayList<>();
+        for (Task task : tasks){
+            if (!task.getStatus()){
+                incompleteTasks.add(task);
+            }
+        }
+        return incompleteTasks;
+    }
+
+    public Task search(String taskName){
+        for (Task task : tasks){
+            if (task.getName().equals(taskName)){
+                return task;
+            }
+        }
+        System.out.println("The task was not found or does not exist!");
+        return null;
+    }
+
+    public ArrayList<String> alphabeticalA(){
+        ArrayList<String> alphabeticalAscending = new ArrayList<>();
+        for (Task task : tasks){
+            alphabeticalAscending.add(task.getName());
+        }
+        Collections.sort(alphabeticalAscending);
+        return alphabeticalAscending;
+    }
+
+    public ArrayList<String> alphabeticalD(){
+        ArrayList<String> alphabeticalDescending = new ArrayList<>();
+        for (Task task : tasks){
+            alphabeticalDescending.add(task.getName());
+        }
+        Collections.sort(alphabeticalDescending);
+        Collections.reverse(alphabeticalDescending);
+        return alphabeticalDescending;
+    }
+
+}
\ No newline at end of file
diff --git a/src/test/java/com/booleanuk/core/TaskTest.java b/src/test/java/com/booleanuk/core/TaskTest.java
new file mode 100644
index 000000000..40d184edd
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/TaskTest.java
@@ -0,0 +1,51 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class TaskTest {
+
+    @Test
+    public void testValidTask(){
+        Task task = new Task("Code");
+
+        Assertions.assertFalse(task.name.isEmpty());
+        Assertions.assertFalse(task.completed);
+    }
+
+    @Test
+    public void testGetName(){
+        Task task = new Task("Run");
+
+        String name = task.getName();
+        Assertions.assertEquals("Run", name);
+    }
+
+    @Test
+    public void testChangeStatusTrue(){
+        Task task = new Task("Run");
+
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+    }
+
+    @Test
+    public void testChangeStatusFalse(){
+        Task task = new Task("Run");
+
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+        task.setStatus(false);
+        Assertions.assertFalse(task.getStatus());
+    }
+
+    @Test
+    public void testGetStatus(){
+        Task task = new Task("Run");
+
+        Assertions.assertFalse(task.getStatus());
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+    }
+
+}
diff --git a/src/test/java/com/booleanuk/core/TodoListTest.java b/src/test/java/com/booleanuk/core/TodoListTest.java
index 0bef779a4..4b65da3ef 100644
--- a/src/test/java/com/booleanuk/core/TodoListTest.java
+++ b/src/test/java/com/booleanuk/core/TodoListTest.java
@@ -3,11 +3,164 @@
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
+import java.util.ArrayList;
+import java.util.List;
+
 class TodoListTest {
+
+    @Test
+    public void testAddTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task = new Task("Swim");
+
+        toDoList.addTask(task);
+        Assertions.assertTrue(toDoList.tasks.contains(task));
+    }
+
     @Test
-    public void exampleTest() {
-        String hello = "Hello";
-        Assertions.assertEquals("Hello", hello);
-        Assertions.assertNotEquals("Goodbye", hello);
+    public void testRemoveTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("Sing");
+        Task task2 = new Task("Jump");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+
+        Assertions.assertTrue(toDoList.tasks.contains(task1));
+        Assertions.assertTrue(toDoList.tasks.contains(task2));
+        toDoList.removeTask("Jump");
+        Assertions.assertFalse(toDoList.tasks.contains(task2));
+
+    }
+
+    @Test
+    public void testSeeAllTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertEquals(List.of("a", "b", "c"), toDoList.seeAllTasks());
     }
+
+    @Test
+    public void testChangeStatus() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertFalse(task1.getStatus());
+        Assertions.assertFalse(task2.getStatus());
+        Assertions.assertFalse(task3.getStatus());
+        toDoList.changeStatus(task2, true);
+        toDoList.changeStatus(task3, true);
+        Assertions.assertFalse(task1.getStatus());
+        Assertions.assertTrue(task2.getStatus());
+        Assertions.assertTrue(task3.getStatus());
+
+    }
+
+    @Test
+    public void testGetCompletedTasks() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.changeStatus(task2, true);
+        toDoList.changeStatus(task3, true);
+
+        Assertions.assertEquals(List.of(task2, task3), toDoList.getCompletedTasks());
+
+    }
+
+    @Test
+    public void testGetIncompleteTasks() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+        toDoList.changeStatus(task2, true);
+        toDoList.changeStatus(task3, true);
+
+        Assertions.assertEquals(List.of(task1, task4), toDoList.getIncompleteTasks());
+
+    }
+
+    @Test
+    public void testSearchExists() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Task searchedTask = toDoList.search("d");
+        Assertions.assertEquals(task4, searchedTask);
+    }
+
+    @Test
+    public void testSearchDoesntExists() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Task searchedTask = toDoList.search("e");
+        Assertions.assertNull(searchedTask);
+    }
+
+    @Test
+    public void testAlphabeticalA() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("d");
+        Task task2 = new Task("c");
+        Task task3 = new Task("b");
+        Task task4 = new Task("a");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Assertions.assertEquals(List.of("a", "b", "c", "d"), toDoList.alphabeticalA());
+    }
+
+    @Test
+    public void testAlphabeticalD() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Assertions.assertEquals(List.of("d", "c", "b", "a"), toDoList.alphabeticalD());
+    }
+
+
 }
diff --git a/src/test/java/com/booleanuk/extension/TaskTest.java b/src/test/java/com/booleanuk/extension/TaskTest.java
new file mode 100644
index 000000000..25d39dc0e
--- /dev/null
+++ b/src/test/java/com/booleanuk/extension/TaskTest.java
@@ -0,0 +1,81 @@
+package com.booleanuk.extension;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Field;
+
+public class TaskTest {
+
+    // Had to add this to reset static counter in between different tests
+    @BeforeEach
+    public void resetCounter() throws NoSuchFieldException, IllegalAccessException {
+        Field counterField = Task.class.getDeclaredField("counter");
+        counterField.setAccessible(true);
+        counterField.set(null, 0); // Reset the static counter to 0
+    }
+
+    @Test
+    public void testGetId(){
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+
+        Assertions.assertEquals(1, task1.getId());
+        Assertions.assertEquals(2, task2.getId());
+        Assertions.assertEquals(3, task3.getId());
+    }
+
+    @Test
+    public void testChangeName(){
+        Task task = new Task("Code");
+        Assertions.assertEquals("Code", task.getName());
+        task.changeName("Jump");
+        Assertions.assertEquals("Jump", task.getName());
+    }
+
+    @Test
+    public void testValidTask(){
+        Task task = new Task("Code");
+
+        Assertions.assertFalse(task.getName().isEmpty());
+        Assertions.assertFalse(task.getStatus());
+    }
+
+    @Test
+    public void testGetName(){
+        Task task = new Task("Run");
+
+        String name = task.getName();
+        Assertions.assertEquals("Run", name);
+    }
+
+    @Test
+    public void testChangeStatusTrue(){
+        Task task = new Task("Run");
+
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+    }
+
+    @Test
+    public void testChangeStatusFalse(){
+        Task task = new Task("Run");
+
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+        task.setStatus(false);
+        Assertions.assertFalse(task.getStatus());
+    }
+
+    @Test
+    public void testGetStatus(){
+        Task task = new Task("Run");
+
+        Assertions.assertFalse(task.getStatus());
+        task.setStatus(true);
+        Assertions.assertTrue(task.getStatus());
+    }
+
+}
\ No newline at end of file
diff --git a/src/test/java/com/booleanuk/extension/ToDoListTest.java b/src/test/java/com/booleanuk/extension/ToDoListTest.java
new file mode 100644
index 000000000..6af2bf480
--- /dev/null
+++ b/src/test/java/com/booleanuk/extension/ToDoListTest.java
@@ -0,0 +1,217 @@
+package com.booleanuk.extension;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Field;
+import java.util.List;
+
+class TodoListTest {
+
+    // Had to add this to reset static counter in between different tests
+    @BeforeEach
+    public void resetCounter() throws NoSuchFieldException, IllegalAccessException {
+        Field counterField = Task.class.getDeclaredField("counter");
+        counterField.setAccessible(true);
+        counterField.set(null, 0);
+    }
+
+    @Test
+    public void testAddTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task = new Task("Swim");
+
+        toDoList.addTask(task);
+        Assertions.assertTrue(toDoList.tasks.contains(task));
+    }
+
+    @Test
+    public void testGetTask(){
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertEquals(task1, toDoList.getTask(1));
+        Assertions.assertEquals(task2, toDoList.getTask(2));
+        Assertions.assertEquals(task3, toDoList.getTask(3));
+    }
+
+    @Test
+    public void testUpdateName(){
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertEquals("a", toDoList.getTask(1).getName());
+        Assertions.assertEquals("b", toDoList.getTask(2).getName());
+        Assertions.assertEquals("c", toDoList.getTask(3).getName());
+
+        toDoList.updateName(1, "x");
+        toDoList.updateName(2, "y");
+        toDoList.updateName(3, "z");
+        Assertions.assertEquals("x", task1.getName());
+        Assertions.assertEquals("y", task2.getName());
+        Assertions.assertEquals("z", task3.getName());
+
+    }
+
+    @Test
+    public void testRemoveTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("Sing");
+        Task task2 = new Task("Jump");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+
+        Assertions.assertTrue(toDoList.tasks.contains(task1));
+        Assertions.assertTrue(toDoList.tasks.contains(task2));
+        toDoList.removeTask("Jump");
+        Assertions.assertFalse(toDoList.tasks.contains(task2));
+
+    }
+
+    @Test
+    public void testSeeAllTask() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertEquals(List.of("a", "b", "c"), toDoList.seeAllTasks());
+    }
+
+    @Test
+    public void testChangeStatusWithId() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+
+        Assertions.assertFalse(task1.getStatus());
+        Assertions.assertFalse(task2.getStatus());
+        Assertions.assertFalse(task3.getStatus());
+        Assertions.assertEquals(2, task2.getId());
+        Assertions.assertEquals(3, task3.getId());
+        toDoList.changeStatus(2, true);
+        toDoList.changeStatus(3, true);
+        Assertions.assertFalse(task1.getStatus());
+        Assertions.assertTrue(task2.getStatus());
+        Assertions.assertTrue(task3.getStatus());
+
+    }
+
+    @Test
+    public void testGetCompletedTasks() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        Assertions.assertEquals(2, task2.getId());
+        Assertions.assertEquals(3, task3.getId());
+        toDoList.changeStatus(2, true);
+        toDoList.changeStatus(3, true);
+
+        Assertions.assertEquals(List.of(task2, task3), toDoList.getCompletedTasks());
+
+    }
+
+    @Test
+    public void testGetIncompleteTasks() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+        toDoList.changeStatus(2, true);
+        toDoList.changeStatus(3, true);
+
+        Assertions.assertEquals(List.of(task1, task4), toDoList.getIncompleteTasks());
+
+    }
+
+    @Test
+    public void testSearchExists() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Task searchedTask = toDoList.search("d");
+        Assertions.assertEquals(task4, searchedTask);
+    }
+
+    @Test
+    public void testSearchDoesntExists() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Task searchedTask = toDoList.search("e");
+        Assertions.assertNull(searchedTask);
+    }
+
+    @Test
+    public void testAlphabeticalA() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("d");
+        Task task2 = new Task("c");
+        Task task3 = new Task("b");
+        Task task4 = new Task("a");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Assertions.assertEquals(List.of("a", "b", "c", "d"), toDoList.alphabeticalA());
+    }
+
+    @Test
+    public void testAlphabeticalD() {
+        ToDoList toDoList = new ToDoList();
+        Task task1 = new Task("a");
+        Task task2 = new Task("b");
+        Task task3 = new Task("c");
+        Task task4 = new Task("d");
+        toDoList.addTask(task1);
+        toDoList.addTask(task2);
+        toDoList.addTask(task3);
+        toDoList.addTask(task4);
+
+        Assertions.assertEquals(List.of("d", "c", "b", "a"), toDoList.alphabeticalD());
+    }
+
+}
+