decide.nolog.cz/app/components/create-options-text.js

import classic from 'ember-classic-decorator';
import { action } from '@ember/object';
import { inject as service } from '@ember/service';
import Component from '@ember/component';
import { next } from '@ember/runloop';

@classic
export default class CreateOptionsText extends Component {
  @action
  addOption(element) {
    let fragment = this.store.createFragment('option');
    let options = this.options;
    let position = this.options.indexOf(element) + 1;
    options.insertAt(
      position,
      fragment
    );
  }

  @action
  deleteOption(element) {
    let position = this.options.indexOf(element);
    this.options.removeAt(position);
  }

  enforceMinimalOptionsAmount() {
    let options = this.options;

    while (options.length < 2) {
      options.pushObject(
        this.store.createFragment('option')
      );
    }
  }

  @service('store')
  store;

  init() {
    super.init(...arguments);

    // need to delay pushing fragments into options array to prevent
    // > You modified "disabled" twice on <(unknown):ember330> in a single render.
    // error.
    next(() => {
      this.enforceMinimalOptionsAmount();
    });
  }
}