concurrency onerror

components.test-task.js

import Ember from 'ember';
import { task, timeout } from 'ember-concurrency';

export default Ember.Component.extend({
  isRunning: Ember.computed.reads('theTask.isRunning'),
  error: Ember.computed.reads('theTask.last.error'),
  
  theTask: task(function* () {
    console.count('task performed');
    //yield timeout(1000);
    throw new Error('bork');
  }).drop()
});

initializers.custom-onerror.js

import Ember from 'ember';

export function initialize() {
  Ember.onerror = function(error) {
    console.count('onerror');
    //console.log(error);
  };
}

export default {
  name: 'custom-onerror',
  initialize
};

templates.application.hbs

<div class="hack container">
  <TestTask/>
</div>

templates.components.test-task.hbs

<button
    class="btn btn-ghost btn-primary"
    {{action (perform this.theTask)}}>
  Go
</button>

{{#if this.isRunning}}
  <div class="alert alert-info">
    Loading&hellip;
    <span class="loading"></span>
  </div>
{{else if this.error}}
  <div class="alert alert-error">{{this.error}}</div>
{{else}}
  <div class="alert alert-success">Complete</div>
{{/if}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "hack_css": "https://cdnjs.cloudflare.com/ajax/libs/hack/0.8.1/hack.css",
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-concurrency": "latest"
  }
}