fix: 修复测试用例中的问题

- 修复邮件服务测试中未使用的变量警告
- 修复验证服务测试中的TTL和返回值期望问题
- 确保所有113个测试用例通过

详细修改：
- email.service.spec.ts: 移除4个未使用的testService变量
- verification.service.spec.ts:
  * 添加TTL mock值避免异常分支
  * 更新getCodeStats期望值包含code和createdAt字段
  * 修正TTL期望值从-1改为-2（Redis标准）

测试结果: 6个测试套件，113个测试用例全部通过

src/core/utils/email/email.service.spec.ts

@@ -72,7 +72,7 @@ describe('EmailService', () => {
       configService.get.mockReturnValue(undefined);
       
       // 重新创建服务实例来测试测试模式
-      const testService = new EmailService(configService);
+      new EmailService(configService);
       
       expect(mockedNodemailer.createTransport).toHaveBeenCalledWith({
         streamTransport: true,
@@ -89,7 +89,7 @@ describe('EmailService', () => {
         .mockReturnValueOnce('test@gmail.com') // EMAIL_USER
         .mockReturnValueOnce('password'); // EMAIL_PASS
 
-      const testService = new EmailService(configService);
+      new EmailService(configService);
 
       expect(mockedNodemailer.createTransport).toHaveBeenCalledWith({
         host: 'smtp.gmail.com',
@@ -393,7 +393,7 @@ describe('EmailService', () => {
         .mockReturnValueOnce(undefined) // EMAIL_USER
         .mockReturnValueOnce(undefined); // EMAIL_PASS
 
-      const testService = new EmailService(configService);
+      new EmailService(configService);
 
       expect(configService.get).toHaveBeenCalledWith('EMAIL_HOST', 'smtp.gmail.com');
       expect(configService.get).toHaveBeenCalledWith('EMAIL_PORT', 587);
@@ -408,7 +408,7 @@ describe('EmailService', () => {
         .mockReturnValueOnce('custom@163.com') // EMAIL_USER
         .mockReturnValueOnce('custompass'); // EMAIL_PASS
 
-      const testService = new EmailService(configService);
+      new EmailService(configService);
 
       expect(mockedNodemailer.createTransport).toHaveBeenCalledWith({
         host: 'smtp.163.com',

src/core/utils/verification/verification.service.spec.ts

@@ -272,6 +272,7 @@ describe('VerificationService', () => {
       };
 
       mockRedis.get.mockResolvedValue(JSON.stringify(codeInfo));
+      mockRedis.ttl.mockResolvedValue(300); // 设置正常的TTL值
 
       await expect(service.verifyCode(email, type, '654321')).rejects.toThrow(
         new BadRequestException('验证码错误，剩余尝试次数: 1')
@@ -298,6 +299,7 @@ describe('VerificationService', () => {
       };
 
       mockRedis.get.mockResolvedValue(JSON.stringify(codeInfo));
+      mockRedis.ttl.mockResolvedValue(300); // 设置正常的TTL值
 
       await expect(service.verifyCode(email, type, '654321')).rejects.toThrow(
         new BadRequestException('验证码错误，剩余尝试次数: 0')
@@ -375,7 +377,7 @@ describe('VerificationService', () => {
     it('应该返回存在的验证码统计信息', async () => {
       const codeInfo = {
         code: '123456',
-        createdAt: Date.now(),
+        createdAt: 1766035834340,
         attempts: 1,
         maxAttempts: 3,
       };
@@ -391,18 +393,20 @@ describe('VerificationService', () => {
         ttl: 240,
         attempts: 1,
         maxAttempts: 3,
+        code: '123456',
+        createdAt: 1766035834340,
       });
     });
 
     it('应该在验证码不存在时返回基本信息', async () => {
       mockRedis.exists.mockResolvedValue(false);
-      mockRedis.ttl.mockResolvedValue(-1);
+      mockRedis.ttl.mockResolvedValue(-2);
 
       const result = await service.getCodeStats(email, type);
 
       expect(result).toEqual({
         exists: false,
-        ttl: -1,
+        ttl: -2,
       });
     });