Can't access property "lastSuccessful", this[taskName] is undefined

[esbanarango]

🐞 Describe the Bug

When using the @lastValue decorator and passing the path of a task. There is an error:

Note: This was working before with ember-concurrency-decorators.

🔬 Minimal Reproduction

export default class MyService extends Service {
  @dropTask
  *myTask() {
    yield null;
  };
}

import { lastValue } from 'ember-concurrency';

export default class MyComponent extends Component {
  @service myService;
  @lastValue('myService.myTask') value;
}

🌍 Environment

• "ember-source": "3.26.1",
• "ember-concurrency": "2.0.3"

[maxfierke]

Thanks for the heads up about this! I've opened a PR to document this as something that's been removed in ember-concurrency v2, as restoring the behavior would rely on using Ember.get or implementing our own support for chained property access here. I think the recommendation would be to refactor this so that it can read a property directly on the component, e.g.:

import { lastValue } from 'ember-concurrency';

export default class MyComponent extends Component {
  @service myService;
  get myServiceTask() { return this.myService.myTask; }
  @lastValue('myServiceTask') value;
}

Or otherwise, you could put the lastValue on the class as a property if you're reading it a lot / don't need to expose components to the task:

import { lastValue } from 'ember-concurrency';

export default class MyService extends Service {
  @dropTask
  *myTask() {
    yield null;
  };
  @lastValue('myTask') myTaskValue;
}