Inflearn Community Q&A

 ```typescript

async create({ email, password, mobileNumber }) {
    const user = await this.userRepository.findOne({ where: { email } });
    if (user) throw new ConflictException('이미 등록된 이메일 입니다.');

    return await this.userRepository.save({ email, password, mobileNumber });
  }

일때

findOne({ where: { email } }) {
    const users = this.mydb.filter((el) => el.email === email);
    if (users.length) return { ...users[0] };

    return null;
  }

입니다.