Test Unit Jasmine e Karma Angular

I'm doing unit testing on angle 6, I'm having trouble testing this branch, I use it to observe how big the screen is to decide how many columns I'll display

@Component({
  selector: 'app-rdesp-waiting-approval',
  templateUrl: './rdesp-waiting-approval.component.html',
  styleUrls: ['./rdesp-waiting-approval.component.scss'],
  animations: fuseAnimations

})
export class RdespWaitingForApproval implements OnInit  {
   this.watcher = media.subscribe((change: MediaChange) => {
      this.activeMediaQuery = change ? `'${change.mqAlias}' = (${change.mediaQuery})` : '';
          if ( change.mqAlias == 'xs') {      
           this.displayedColumns = ['job' ,'name', 'totalValue'];
          }else{
            this.displayedColumns = ['internalId','DateOfPublication', 'alias', 'job', 'name','totalValue'];
      }
    });

  
  }