Keep Latest Task - In Order

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { keepLatestTask, task } from 'ember-concurrency-decorators';
import { didCancel, timeout } from 'ember-concurrency';

export default class ApplicationController extends Controller {
  n = 0;
  
  @keepLatestTask
  * fooTask() {
    yield timeout(2000);
  }

  @task
  * orderFooTask() {
    this.fooTask.perform();
    if (this.fooTask.isQueued) {
      yield this.fooTask.last
    }
    yield this.fooTask.last
  }

  @action
  triggerTask() {
    const n = this.incrementProperty('n');
    this.orderFooTask.perform().catch(e => {}).finally(() => console.log(`n = ${n}`));
  }
}

templates.application\.hbs

<button {{on "click" this.triggerTask}}>Run Task</button>
<p>View console for messages</p>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0",
    "ember-concurrency": "1.1.7",
    "ember-concurrency-decorators": "1.0.0"
  }
}