JavaScript-转换功能至少具有两个回调样式以承诺样式

Question

我从回调风格转向承诺风格，以避免回调使我难以维护代码。我使用 util 模块通过 util.promisify() 导入和转换回调函数，但问题是该函数是否至少有两个回调。函数如何以承诺形式返回，那么我如何管理代码以从两个条件回调中获取承诺。

回调样式示例。

loginAccount = async ({email,password},success,unsuccess) => {
    this.db.query(`SELECT id, password FROM account WHERE email = ?`,[email],(err,result)=>{
      if (err) throw err
      if (result.length === 0) {
        unsuccess("ไม่มีบัญชีนี้อยู่ในระบบ ตรวจสอบอีเมลว่าถูกต้องหรือไม่")
        return
      }
      const account = result[0]
      bcrypt.compare(password,account.password,(error,response)=>{
        if (err) throw err
        if (!(response)) {
          unsuccess("รหัสผ่านไม่ถูกต้อง")
          return
        }
        this.getUser(account.id,success,unsuccess)
      })
    })
  }

我可以像这样转换成承诺形式，但我不知道如何返回成功或不成功。

  loginAccount = async ({email,password},success,unsuccess) => {
    const result = await this.query(`SELECT id, password FROM account WHERE email = ?`,email)
    if (result.length > 0) {
      const account = result[0]
      const response = await this.compareHash(password,account.password)
      if (response) {
        return this.getUser(account.id)
      }
      else {
        // return unsuccess
        // Wrong password
      }
    }
    else {
      // return unsuccess
      // No account in the database
    }
}

回调风格和承诺风格的另一个例子。

registerAccount = async ({firstname,lastname,email,password},success,unsuccess) => {
    this.hasAccount(email,(exist)=>{
      if (exist === true) {
        unsuccess("บัญชีนี้เคยลงทะเบียนไว้แล้ว")
        return
      }
      bcrypt.hash(password,this.saltRound,(err,hash)=>{
        if (err) throw err
        this.db.query(`INSERT INTO account (firstname,lastname,email,password) VALUES(?,?,?,?); 
                      SET @user_id = LAST_INSERT_ID(); INSERT IGNORE INTO role (id) VALUES (@user_id);
                      INSERT INTO student_data (id) VALUES (@user_id); 
                      INSERT INTO profile_image (id) VALUES (@user_id);`,
        [firstname,lastname,email,hash],
        (err,result)=>{
          if (err) throw err
          success()
        })
      })
    })
  }

registerAccount = async ({firstname,lastname,email,password},success,unsuccess) => {
    const exist = await this.hasAccount(email)
    if (exist) {
      // unsuccess function return
      // account is already exists.
      return
    }
    const hash = await this.generateHash(password,this.saltRound)
    const registerQuery = `INSERT INTO account (firstname,lastname,email,password) VALUES(?,?,?,?); 
                          SET @user_id = LAST_INSERT_ID(); INSERT IGNORE INTO role (id) VALUES (@user_id);
                          INSERT INTO student_data (id) VALUES (@user_id); 
                          INSERT INTO profile_image (id) VALUES (@user_id);`
    const result = await this.query(registerQuery,[firstname,lastname,email,hash])
    
    // success function
  }

this.query、this.compareHash 和 this.generateHash，我正在使用名为 util.promisify() 的库 code> 获取 Promise 函数。

this.query 来自 mysql 查询函数，this.compareHash 和 this.generateHash 均来自 >bcrypt.compare 和 brcypt.hash

this.compareHash 将使用明文密码和哈希密码来比较哈希值。

this.generataHash 将使用纯密码和盐轮生成哈希值以返回哈希密码。

this.getUser 函数。

  getUser = async (id) => {
    const result = await this.query(`SELECT * FROM profile_view WHERE id = ?`,id)
    return result[0]
  }