diff --git a/lab1/main_test.js b/lab1/main_test.js
index 74a716b..f835344 100644
--- a/lab1/main_test.js
+++ b/lab1/main_test.js
@@ -3,6 +3,50 @@ const assert = require('assert');
 const { MyClass, Student } = require('./main');
 
 test("Test MyClass's addStudent", () => {
+    const Class = new MyClass();
+    const student = new Student();
+    const id = Class.addStudent(student);
+    assert.strictEqual(id, 0);
+    assert.strictEqual(Class.addStudent({}), -1);
+});
+
+test("Test MyClass's getStudentById", () => {
+    const Class =  new MyClass();
+    const student = new Student();
+    student.setName("John");
+
+    const id = Class.addStudent(student);
+    const StudentID = Class.getStudentById(id);
+
+    assert.strictEqual(StudentID.getName(), "John");
+    assert.strictEqual(Class.getStudentById(-1), null); 
+    assert.strictEqual(Class.getStudentById(999), null);
+
+});
+
+test("Test Student's setName", () => {
+    const student = new Student();
+    student.setName(123);  
+    assert.strictEqual(student.getName(), "");
+
+    student.setName("John");
+    const StudentName = student.getName();
+
+    
+    assert.strictEqual(StudentName, "John");
+    
+});
+
+test("Test Student's getName", () => {
+    const student = new Student();
+
+    // "" in default
+    assert.strictEqual(student.getName(), "");
+    
+    student.setName("John");
+    const StudentName = student.getName();
+    assert.strictEqual(StudentName, "John");
+=======
     // TODO
     throw new Error("Test not implemented");
 });
diff --git a/lab2/main_test.js b/lab2/main_test.js
index 5034468..b204791 100644
--- a/lab2/main_test.js
+++ b/lab2/main_test.js
@@ -1,6 +1,99 @@
 const test = require('node:test');
 const assert = require('assert');
+const fs = require('fs');
+
+// 模擬 fs.readFile
+function mockReadFile(path, encoding, callback) {
+    callback(null, 'Alice\nBob\nCharlie'); // Stub
+}
+const mockFsRead = test.mock.method(fs, 'readFile', mockReadFile);
+
+const { Application, MailSystem } = require('./main');
+
+test('MailSystem: write()', () => {
+    const mailSystem = new MailSystem;
+    assert.strictEqual(mailSystem.write('Alice'), 'Congrats, Alice!');
+});
+
+test('MailSystem: send() success case', () => {
+    function returnHigh() { return 0.9; } // Stub
+    const mailSystem = new MailSystem();
+    const mockRandom = test.mock.method(Math, 'random', returnHigh);
+    assert.strictEqual(mailSystem.send('Alice', 'Congrats, Alice!'), true);
+    mockRandom.mock.restore();
+});
+
+test('MailSystem: send() failure case', () => {
+    function returnLow() { return 0.1; } // Stub
+    const mailSystem = new MailSystem();
+    const mockRandom = test.mock.method(Math, 'random', returnLow);
+    assert.strictEqual(mailSystem.send('Alice', 'Congrats, Alice!'), false);
+    mockRandom.mock.restore();
+});
+
+test('Application: constructor initializes names', async () => {
+    const app = new Application();
+    await new Promise((resolve) => setTimeout(resolve, 10)); // Wait for async init
+    assert.deepStrictEqual(app.people, ['Alice', 'Bob', 'Charlie']);
+    assert.deepStrictEqual(app.selected, []);
+});
+
+test('Application: getRandomPerson()', () => {
+    function returnFirst() { return 0; }
+    const app = new Application();
+    const mockRandom = test.mock.method(Math, 'random', returnFirst);
+    assert.strictEqual(app.getRandomPerson(), 'Alice');
+    mockRandom.mock.restore();
+});
+
+test('Application: selectNextPerson()', async () => {
+    const application = new Application();
+    await new Promise(resolve => setTimeout(resolve, 50));
+
+    function returnApple() {
+        return 'Apple';
+    }
+    const mockrandompersonA = test.mock.method(application, 'getRandomPerson', returnApple);
+    assert.strictEqual(application.selectNextPerson(), 'Apple');
+    assert.deepStrictEqual(application.selected, ['Apple']);
+    mockrandompersonA.mock.restore();
+    
+    let cnt = 0;
+    function returnAppleThenBanana() {
+        return cnt++ === 0 ? 'Apple' : 'Banana';
+    }
+    const mockrandompersonAB = test.mock.method(application, 'getRandomPerson', returnAppleThenBanana);
+    assert.strictEqual(application.selectNextPerson(), 'Banana');
+    assert.deepStrictEqual(application.selected, ['Apple', 'Banana']);
+    mockrandompersonAB.mock.restore();
+
+    function returnOrange() {
+        return 'Orange';
+    }
+    const mockrandompersonO = test.mock.method(application, 'getRandomPerson', returnOrange);
+    assert.strictEqual(application.selectNextPerson(), 'Orange');
+    assert.deepStrictEqual(application.selected, ['Apple', 'Banana', 'Orange']);
+    mockrandompersonO.mock.restore();
+    
+    assert.strictEqual(application.selectNextPerson(), null);
+});
+
+test('Application: notifySelected()', () => {
+    const app = new Application();
+    app.selected = ['Alice', 'Bob'];
+    
+    const mockWrite = test.mock.method(app.mailSystem, 'write');
+    const mockSend = test.mock.method(app.mailSystem, 'send');
+    
+    app.notifySelected();
+    
+    assert.strictEqual(mockWrite.mock.callCount(), 2);
+    assert.strictEqual(mockSend.mock.callCount(), 2);
+    mockWrite.mock.restore();
+    mockSend.mock.restore();
+});
+=======
 const { Application, MailSystem } = require('./main');
 
 // TODO: write your tests here
-// Remember to use Stub, Mock, and Spy when necessary
\ No newline at end of file
+// Remember to use Stub, Mock, and Spy when necessary