如何通过worker.onerror在承诺中冒泡网络工作者错误？ [英] How to bubble a web worker error in a promise via worker.onerror?

问题描述

我正在与一位网络工作者打交道，如果发生错误，他需要报告。通常，我可以使用 worker.onerror 侦听从工作程序引发的任何错误。但是，当错误发生在网络工作者的承诺中时，我无法弄清楚如何使错误回溯到 worker.onerror 。

I'm dealing with a web worker that needs to report back if an error has occured. Normally, I can use worker.onerror to listen to any errors that were thrown from the worker. However, when the error happens in a promise in the web worker, I can't figure out how to bubble the error back up to worker.onerror.

请使用奇数代码段，因为这似乎是证明工作人员行为的唯一方法。 （工作程序在HTML部分中定义）。

Excuse the odd code snippet, as this seems to be the only way to demonstrate worker behavior. (The worker is defined in the HTML section).

function getInlineJS() {
  var js = document.querySelector('[type="javascript/worker"]').textContent;
  var blob = new Blob([js], {
    "type": "text\/plain"
  });
  return URL.createObjectURL(blob);
}

var worker = new Worker(getInlineJS());

worker.onerror = function(err) {
  document.getElementById('errors').innerHTML += 
    "error " + err.message + '\n';
}

worker.onmessage = function (msg) {
  console.log("message recieved", msg);
  document.getElementById('messages').innerHTML += 
    "message " + msg.data + '\n';
}


worker.postMessage("run");
worker.postMessage("promise");

should write "Normal Error and In Promise Error" below and in console (promise error only occurs in console though): <br>

<pre id="errors">
</pre>

messages:
<pre id="messages">
</pre>

<script type="javascript/worker">
self.addEventListener("message", function(e) {
    /* demonstration of normal error bubbling to onerror */
    if (e.data == 'run') {
      throw new Error('Normal Error');
      return;
    }
    new Promise(function(resolve, reject) {
      /* some logic that breaks */
      throw new Error('In Promise Error');
    }).then(function(result) {
      
    }).catch(function(err) {
      /* QUESTION: HOW TO GET THIS ERROR OUT OF WORKER? */
      
      /* it logs to console just fine */
      console.log("In Promise Catch Error:", err);
      
      /* postMessage doesn't work for some reason */
      self.postMessage({error: err});
      
      /* and this doesn't bubble it to worker.onerror */
      throw err; /* doesn't bubble!! */
    });
});
</script>

如何检索承诺中发生的网络工作者错误？

推荐答案

postMessage由于某种原因无法正常工作

postMessage doesn't work for some reason

这是因为您要返回的是对象而不是字符串，请将其更改为 self.postMessage（{error：err.message}）;

That's because you're returning an object instead of a string, change it to self.postMessage({error: err.message});

对于第二个问题，您可以使用 setTimeout（function（）{throw err;}）; 技巧。可以在此处。

As for your second problem, you can use the setTimeout(function() { throw err; }); trick. More information about the situation and trick can be found here.

function getInlineJS() {
  var js = document.querySelector('[type="javascript/worker"]').textContent;
  var blob = new Blob([js], {
    "type": "text\/plain"
  });
  return URL.createObjectURL(blob);
}

var worker = new Worker(getInlineJS());

worker.onerror = function(err) {
  document.getElementById('errors').innerHTML += 
    "error " + err.message + '\n';
}

worker.onmessage = function (msg) {
  console.log("message recieved", msg);
  document.getElementById('messages').innerHTML += 
    "message " + msg.data + '\n';
}


worker.postMessage("run");
worker.postMessage("promise");

should write "Normal Error and In Promise Error" below and in console (promise error only occurs in console though): <br>

<pre id="errors">
</pre>

messages:
<pre id="messages">
</pre>

<script type="javascript/worker">
self.addEventListener("message", function(e) {
    /* demonstration of normal error bubbling to onerror */
    if (e.data == 'run') {
      throw new Error('Normal Error');
      return;
    }
    new Promise(function(resolve, reject) {
      /* some logic that breaks */
    
      throw new Error('In Promise Error');
    }).then(function(result) {
      
    }).catch(function(err) {
      /* it logs to console just fine */
      console.log("In Promise Catch Error:", err);
      
      /* postMessage works when you return a string. */
      self.postMessage({error: err.message});

       setTimeout(function() { throw err; }); 
    });
});
</script>

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