JUnit Tests implemented

build.gradle

@@ -18,6 +18,7 @@ dependencies {
 }
 
 dependencies {
+    implementation 'junit:junit:4.13.1'
     testImplementation group: 'org.junit.jupiter', name: 'junit-jupiter-api', version: '5.5.0'
     testRuntimeOnly group: 'org.junit.jupiter', name: 'junit-jupiter-engine', version: '5.5.0'
 }
@@ -37,7 +38,7 @@ test {
 }
 
 application {
-    mainClassName = "seedu.duke.Duke"
+    mainClassName = "Duke.Duke"
 }
 
 shadowJar {

database/duke.txt

@@ -1 +0,0 @@
-T;X; 

src/test/java/Duke/commands/TaskListTest.java

@@ -0,0 +1,34 @@
+package Duke.commands;
+
+import Duke.Storage;
+import Duke.TaskList;
+import Duke.tasks.Task;
+import Duke.tasks.Todo;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class TaskListTest {
+
+
+    @Test
+    public void add() {
+        ArrayList<Task> tasks = new ArrayList<>();
+        Task tempTask = new Todo("");
+        TaskList taskList = new TaskList(tasks);
+        Task addedTask = taskList.addTask(tempTask);
+        assertNotNull(taskList);
+    }
+
+    @Test
+    public void isValidTaskNumbertest() {
+        TaskList taskList = new TaskList(Arrays.asList(null, null));
+        assertFalse(taskList.isValidTaskNumber(10));
+    }
+
+
+}
+