javascript - ES6 javascript 如何处理一系列 async/await 函数中的错误

Question

我正在任务中测试三个异步/等待函数(functionA、functionB、functionC)的条件序列但是当我执行它时，指出第一个 functionA 不应该通过，

1 - 我没有收到预期的功能失败消息

2 - 当任何函数未通过时，我应该如何处理错误以停止序列？

感谢反馈

console.log

 functionB: functionB passed
 functionC: functionC passed
 task ended

ES6 js

async function functionA(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionA passed');
      } else {
        reject(Error('functionA failed'));
      }
    }, duration);
  });
}

async function functionB(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionB passed');
      } else {
        reject(Error('functionB failed'));
      }
    }, duration);
  });
}

async function functionC(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionC passed');
      } else {
        reject(Error('functionC failed'));
      }
    }, duration);
  });
}

async function executeAsyncTask(condition1, condition2, condition3) {
  let resultFunctionA = true
  if (condition1) {
    resultFunctionA = await functionA(3000, true)
    console.log('functionA: ', resultFunctionA)
  }
  let resultFunctionB = true
  if (resultFunctionA && condition2) {
    resultFunctionB = await functionB(3000, true)
    console.log('functionB: ', resultFunctionB)
  }
  let resultFunctionC = true
  if (resultFunctionB && condition3) {
    resultFunctionC = await functionC(3000, true)
    console.log('functionC: ', resultFunctionC)
  }
  console.log('task ended')
}

// running task with condition1, condition2, condition3 parameters
executeAsyncTask(false, true, true)

Answer 1

1 - I don't get the expected functionA failed message

因为您没有调用 functionA，因为您的 condition1 为 false。

2 - how should I handle errors to stop the sequence when any function is not passing ?

将其包装在 try catch block 中。修改代码以适应您的要求。

这是这篇精彩文章的断言:https://blog.patricktriest.com/what-is-async-await-why-should-you-care/

Here, we've wrapped the entire operation within a normal try/catch block. This way, we can throw and catch errors from synchronous code and asynchronous code in the exact same way. Much simpler.

async function functionA(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionA passed');
      } else {
        reject(Error('functionA failed'));
      }
    }, duration);
  });
}

async function functionB(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionB passed');
      } else {
        reject(Error('functionB failed'));
      }
    }, duration);
  });
}

async function functionC(duration, shouldPass) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (shouldPass) {
        resolve('functionC passed');
      } else {
        reject(Error('functionC failed'));
      }
    }, duration);
  });
}

async function executeAsyncTask(condition1, condition2, condition3) {
  try {
    let resultFunctionA = await functionA(3000, condition1)
    console.log('functionA: ', resultFunctionA)
    let resultFunctionB = await functionB(3000, condition2)
    console.log('functionB: ', resultFunctionB)
    let resultFunctionC = await functionC(3000, condition3)
    console.log('functionC: ', resultFunctionC)
    console.log('task ended')
  } catch (err) {
    console.error(err.message)
  }
}

// running task with condition1, condition2, condition3 parameters
executeAsyncTask(false, true, true)