Add Junit test cases

src/main/java/Deadline.java

@@ -20,9 +20,14 @@ private String getDeadline() {
         return deadline.format(DateTimeFormatter.ofPattern(" MMM dd yyyy"));
     }
 
+    @Override
+    public String toString() {
+        return "[D][" + getStatusIcon()
+                + "]" + description + "(by:" + getDeadline() + ")";
+    }
+
     @Override
     public void printDescription() {
-        System.out.println("[D][" + getStatusIcon()
-                + "]" + description + "(by:" + getDeadline() + ")");
+        System.out.println(toString());
     }
 }

src/main/java/Event.java

@@ -13,9 +13,14 @@ public Event(String description, String time, boolean isDone) {
         this.time = time;
     }
 
+    @Override
+    public String toString() {
+        return "[E][" + getStatusIcon()
+                + "]" + description + "(at:" + time + ")";
+    }
+
     @Override
     public void printDescription() {
-        System.out.println("[E][" + getStatusIcon()
-                + "]" + description + "(at:" + time + ")");
+        System.out.println(toString());
     }
 }

src/main/java/TaskList.java

@@ -9,15 +9,15 @@ public class TaskList {
         this.tasks = new ArrayList<>();
     }
 
-    TaskList(ArrayList<Task> tasks) {
+    public TaskList(ArrayList<Task> tasks) {
         this.tasks = tasks;
     }
 
-    protected int size() {
+    public int size() {
         return tasks.size();
     }
 
-    protected Task get(int i) {
+    public Task get(int i) {
         return tasks.get(i);
     }
 

src/main/java/Ui.java

@@ -7,7 +7,7 @@ public class Ui {
             + "| |_| | |_| |   <  __/\n"
             + "|____/ \\__,_|_|\\_\\___|\n";
 
-    protected void start() {
+    public void start() {
         System.out.println("Hello from\n" + logo);
         System.out.println("    ____________________________________________________________");
         System.out.println("     Hello! I'm Duke\n     What can I do for you?");

src/test/java/DeadlineTest.java

@@ -0,0 +1,14 @@
+import main.java.Deadline;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class DeadlineTest {
+    @Test
+    public void toStringTest() {
+        assertEquals("[D][\u2718] read book(by: Oct 09 2020)",
+                new Deadline(" read book", LocalDate.of(2020, 10, 9)).toString());
+    }
+}

src/test/java/EventTest.java

@@ -0,0 +1,12 @@
+import main.java.Event;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class EventTest {
+    @Test
+    public void toStringTest() {
+        assertEquals("[E][\u2718] read book(at: night)",
+                new Event(" read book", " night").toString());
+    }
+}

src/test/java/TaskListTest.java

@@ -0,0 +1,30 @@
+import main.java.Event;
+import main.java.TaskList;
+import main.java.Task;
+import main.java.Todo;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class TaskListTest {
+    @Test
+    public void sizeTest() {
+        ArrayList<Task> tasks = new ArrayList<>();
+        tasks.add(new Todo("read"));
+        tasks.add(new Event("sleep", "noon"));
+        TaskList taskList = new TaskList(tasks);
+        assertEquals(2, taskList.size());
+    }
+
+    @Test
+    public void getTest() {
+        ArrayList<Task> tasks = new ArrayList<>();
+        tasks.add(new Todo("read"));
+        Event event = new Event("sleep", "noon");
+        tasks.add(event);
+        TaskList taskList = new TaskList(tasks);
+        assertEquals(event, taskList.get(1));
+    }
+}