I saw this error lot of times but any solution for my problem,

my component :

*/

@Component({

  selector: 'ngx-modal-result-training',

  templateUrl: './modal-result-training.component.html',

  styleUrls: ['./modal-result-training.component.scss'],

})

export class ModalResultTrainingComponent implements OnInit {

  @Input() results: IAttempt;

  @Input() training: ITraining;

  public validated = false;

  public opinionForm: FormGroup;

  public selectedStars = 0;

  public hasAlreadyComment = true;

  public percentageScore: number;



  constructor(

    private opinionsService: OpinionsService,

    private userService: UserService,

    private ref: NbDialogRef<ModalResultTrainingComponent>,

    private router: Router,

    private toastrService: NbToastrService,

    private translateService: TranslateService,

    private dialogService: DialogService

  ) {}



  public ngOnInit(): void {

    this.dialogService.refs.push(this.ref);

    this.percentageScore = Math.floor(this.results.score);

    this.validated = this.percentageScore >= this.training.minimalScore;



    this.checkUserOpinion();

    this.initForm();

  }

My test :

const training = {

  id: 'ZGtz6yrEemCNTo5KAytu',

  refProject: 'JGvD1faO8L2vWb66BQ87',

  publicationDate: new Date(),

  version: 1,

  name: 'My project',

  groups: [],

  category: '',

  description: '',

  minimalScore: 80,

  previewPNG: '',

  level: 5,

  gain: 5,

  fromDate: new Date(),

  toDate: new Date(),

  totalSlides: 20,

  stars: 3,

  averageStars: 4,

  comments: 15,

  groupsHistoric: [],

} as ITraining;



const trainingResults = {

  id: 'ZDqzqg',

  version: 1,

  trainingID: 'xSOvDC6vpZTzVqXy5owQ',

  userID: 'qdZDZDqg',

  groupsIDs: [],

  date: new Date(),

  time: 10,

  score: 10,

  validated: true,

  finished: true,

  currentStep: 4,

} as IAttempt;



fdescribe('ModalResultTrainingComponent', () => {

  let component: ModalResultTrainingComponent;

  let fixture: ComponentFixture<ModalResultTrainingComponent>;

  let mockOpinionsService =  jasmine.createSpyObj('OpinionService', ['addOpinion']);

  let mockDialogService = jasmine.createSpyObj('DialogService', ['closeAll', 'refs', 'push']);

  let mockUserService = jasmine.createSpyObj('UserService', ['user$']);

  let mockRouter = jasmine.createSpyObj('Router', ['navigate']);

  let mockToastrService = jasmine.createSpyObj('NbToastrService ', ['success']);

  let mockTranslateService = jasmine.createSpyObj('TranslateService ', ['instant']);

  let nbAclService = jasmine.createSpyObj('NbAclService' , ['allow', 'can', 'register', 'setAccessControl']);

  let nbDialogRef = jasmine.createSpyObj('NbDialogRef', ['push']);



  beforeEach(async () => {

    await TestBed.configureTestingModule({

      declarations: [ModalResultTrainingComponent],

      providers: [

        {provide :  Router, useValue: mockRouter},

        {provide :  OpinionsService, useValue: mockOpinionsService},

        {provide :  UserService, useValue: mockUserService},

        {provide :  DialogService, useValue: mockDialogService},

        {provide :  NbToastrService, useValue: mockToastrService},

        {provide :  TranslateService, useValue: mockTranslateService},

        {provide :  NbDialogRef, useValue: nbDialogRef},

        EntityService,

        {provide : NbAclService, useValue : nbAclService},

        ],

      imports: [

        FireModule,

        RouterModule.forRoot([]),

        NbThemeModule.forRoot(),

        NbDialogModule.forRoot(),

        NbAuthModule.forRoot(),

        TranslateModule.forRoot(),

      ],

      schemas: [NO_ERRORS_SCHEMA],

    }).compileComponents();

  });



  beforeEach(() => {

    fixture = TestBed.createComponent(ModalResultTrainingComponent);

    component = fixture.componentInstance;

    fixture.detectChanges();

    mockOpinionsService = TestBed.inject(OpinionsService);

    mockUserService = TestBed.inject(UserService);

    mockDialogService = TestBed.inject(DialogService);

    mockRouter = TestBed.inject(Router);

    mockToastrService = TestBed.inject(NbToastrService);

    mockTranslateService = TestBed.inject(TranslateService);

    nbAclService = TestBed.inject(NbAclService);

    nbDialogRef = TestBed.inject(NbDialogRef);

    component.training = training;

    component.results = trainingResults;





  });



  it('should create', () => {

    //expect(component.results.validated).toBeTrue();

    expect(component).toBeTruthy();

  });

});

I don't understand why I got this error : " TypeError: this.dialogService.refs.push is not a function"

I try to replace useClass instead of useValue but I had unreachable knowing is angular 11.
I did lot of research but I found anything.

thanks to all for help