javascript - 如何等待connection.connect

Question

我需要一种方法来检查一些 mysql 连接。
在返回函数之前如何等待连接？

function _testConnection( _host, _user, _password, _database) {
  let status = false;
  let connection = mysql.createConnection({
    host     : _host,
    user     : _user,
    password : _password,
    database : _database
  });

  connection.connect((err) => {
    status = !err;
    connection.destroy();
  });

  // How to wait here for the connection?
  return status;
}

Answer 1

您可以创建一个 Promise 并从中获取返回值

function _testConnection( _host, _user, _password, _database) {
  return new Promise((resolve, reject) => {
    let status = false;
    let connection = mysql.createConnection({
      host: _host,
      user: _user,
      password: _password,
      database: _database
    });

    connection.connect((err) => {
      status = !err;
      connection.destroy();
      resolve(status)
    });
  })
}

你可以调用这个函数

_testConnection(...).then(status => {
  console.log(status)
})