Batching ember-concurrency

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { all, task } from 'ember-concurrency';

export default class ApplicationController extends Controller {
  @task({ maxConcurrency: 10, enqueue: true })
  *fetchCollection(item) {
    return yield fakeResponse({ filename: item.filename });
  }

  @task({ drop: true })
  *fetchAllCollections(filteredEvents) {
    console.log('Running');
    return yield all(filteredEvents.map(item => this.fetchCollection.perform(item)));
  }

  @action
  run() {
    let filteredEvents = Array.from({ length: 100 }, (c, i) => ({ filename: `example-${i + 1}` }));
    this.fetchAllCollections.perform(filteredEvents);
  }
}

async function fakeResponse({ filename }) {
  console.time(filename);
  await new Promise(r => setTimeout(r, 1000));
  console.timeEnd(filename);
  return { success: true };
}

templates.application\.hbs

<button type="button" {{on "click" this.run}}>Run</button>

{{#if this.fetchAllCollections.isRunning}}Running{{/if}}

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": "2.0.2"
  }
}