diff --git a/lab2/main_test.js b/lab2/main_test.js
index 5034468e..9ecbae1e 100644
--- a/lab2/main_test.js
+++ b/lab2/main_test.js
@@ -1,6 +1,74 @@
 const test = require('node:test');
 const assert = require('assert');
+const fs=require('fs');
 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
+
+test('mailsystem write',(t)=>{
+	const ms=new MailSystem();
+	assert.strictEqual(ms.write('sam'), 'Congrats, sam!');
+});
+test('mailsystem send',(t)=>{
+	const ms=new MailSystem();
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+	assert.strictEqual(typeof(ms.send('sam','mail')), 'boolean');
+});
+test('mailsystem getName',async (t)=>{
+	fs.writeFileSync('name_list.txt','sam\ntom\njeck','utf8');
+	const app=new Application();
+	const [people, selected] = await app.getNames();
+	assert.strictEqual(people[0], 'sam');
+	assert.strictEqual(people[1], 'tom');
+	assert.strictEqual(people[2], 'jeck');
+	fs.unlinkSync('name_list.txt');
+});
+test('mailsystem getran',async (t)=>{
+	fs.writeFileSync('name_list.txt','sam\ntom\njeck','UTF-8');
+	const app=new Application();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	assert.match(app.getRandomPerson(), /^(sam|tom|jeck)$/);
+	fs.unlinkSync('name_list.txt');
+});
+test('Application selectNextPerson',async (t)=>{
+	fs.writeFileSync('name_list.txt','sam\ntom\njeck','UTF-8');
+	const app=new Application();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	assert.match(app.selectNextPerson(), /^(sam|tom|jeck)$/);
+	assert.match(app.selectNextPerson(), /^(sam|tom|jeck)$/);
+	assert.match(app.selectNextPerson(), /^(sam|tom|jeck)$/);
+	assert.strictEqual(app.selectNextPerson(), null);
+	fs.unlinkSync('name_list.txt');
+});
+test('Application notifySelected',async (t)=>{
+	fs.writeFileSync('name_list.txt','sam\ntom\njeck','UTF-8');
+	const app=new Application();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	await app.getNames();
+	app.selectNextPerson();
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	app.selectNextPerson();
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	assert.strictEqual(app.notifySelected(), undefined);
+	fs.unlinkSync('name_list.txt');
+});
\ No newline at end of file