您如何从第三方库中捕获“未捕获（承诺）错误”？

Question

如果我调用的同步第三方函数从它正在调用的异步函数中抛出错误，我如何捕获错误？

// some asynchronous function thirdPartyFun calls
function thirdPartyAsyncFun() {
  console.log('thirdPartyAsyncFun() called.');
  return new Promise((resolve, reject) => {
    throw new Error('Error Message!')
  });
}

// a third-party function I want to call
function thirdPartyFun() {
  console.log('thirdPartyFun() called.');
  thirdPartyAsyncFun();
}

// my function
async function myLocalFun() {
  try {
    // I want to catch any errors this is throwing,
    // but calling this produces 'Uncaught (in promise) Error'
    // in the browser when there are errors
    thirdPartyFun();
    
    // This would work, but I can't call thirdPartyAsyncFun directly
    // await thirdPartyAsyncFun();
  } catch (er) {
    // I want this to get called, but it doesn't!
    console.log(er.message)
  }
}

myLocalFun();

上面的jsfiddle。

Answer 1

您的第三方函数并不像您想象的那样同步。不会调用 catch 块，因为当您运行异步函数时会继续执行并且不会引发异常。您必须添加：

await thirdPartyAsyncFun();

或者

thirdPartyAsyncFun().then(() => {
/* Do here whatever you want */
}).catch(error => {
console.log(`error: ${error} `);
});

http://jsfiddle.net/quk4zwLg/1/