old_contents: import Component from '@ember/component';
  import { computed } from '@ember/object';
  import { setDiff } from '@ember/object/computed';
  import { inject as service } from '@ember/service';
  import { isNone } from '@ember/utils';
  
  export default class TrackingTables extends Component {
    tagName = '';
  
    @service account;
  
    tracks = null;
    friends = null;
  
    @computed('tracks.[]', 'friends.[]', 'account.user.id')
    get friendsTracks() {
      let self = this.get('account.user.id');
      if (isNone(self)) {
        return [];
      }
  
      let friends = this.friends;
  
      return this.tracks.filter(track => track.pilot.id === self || friends.includes(track.pilot.id));
    }
  
    @setDiff('tracks', 'friendsTracks') othersTracks;
  }
  
new_contents: import { computed } from '@ember/object';
  import { setDiff } from '@ember/object/computed';
  import { inject as service } from '@ember/service';
  import { isNone } from '@ember/utils';
  import Component from '@glimmer/component';
  
  export default class TrackingTables extends Component {
    @service account;
  
    tracks = null;
    friends = null;
  
    @computed('args.{tracks.[],friends.[]}', 'account.user.id')
    get friendsTracks() {
      let self = this.account.user?.id;
      if (isNone(self)) {
        return [];
      }
  
      let friends = this.args.friends;
  
      return this.args.tracks.filter(track => track.pilot.id === self || friends.includes(track.pilot.id));
    }
  
    @setDiff('args.tracks', 'friendsTracks') othersTracks;
  }
  
subject: Convert to Glimmer component