add validation in create member

src/users/users.service.ts

@@ -36,6 +36,21 @@ export class UsersService {
   async create(createUserDto: CreateUserDto, currentUser: any) {
     const roles = await this.roleService.findOne(createUserDto.roleId);
     const superior = await this.findByUsername(currentUser.username);
+
+    const check = await this.usersRepository.findOne({
+      username: createUserDto.username,
+    });
+
+    if (check) {
+      throw new HttpException(
+        {
+          statusCode: HttpStatus.NOT_ACCEPTABLE,
+          error: 'Username Already Exist',
+        },
+        HttpStatus.NOT_FOUND,
+      );
+    }
+
     const salt = randomStringGenerator();
 
     const userData = new User();