sequelize-users-repository.js

class SequelizeUsersRepository {
  constructor({ userModel }) {
    this.userModel = userModel;
  }
  
  add(user) {
    const { valid, errors } = user.validate();

    if(!valid) {
      const error = new Error('ValidationError');
      error.details = errors;

      return Promise.reject(error);
    }

    return this.userModel
      .create(user.attributes)
      .then((dbUser) => dbUser.dataValues);
  }
}