✅ improve dataset-detail coverage

src/app/datasets/dataset-detail/dataset-detail.component.spec.ts

@@ -1,12 +1,15 @@
 import { ComponentFixture, TestBed } from '@angular/core/testing';
+import { SpyLocation } from '@angular/common/testing';
 import { RouterTestingModule } from '@angular/router/testing';
 import { HttpClientTestingModule } from '@angular/common/http/testing';
 import { of } from 'rxjs';
-import { ActivatedRoute } from '@angular/router';
+import { ActivatedRoute, Router } from '@angular/router';
+import { Location } from '@angular/common';
 import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
 
 import { DatasetDetailComponent } from './dataset-detail.component';
 import { Dataset } from '../datasets.model';
+import { SamplesComponent } from 'src/app/samples/samples.component';
 
 const dataset: Dataset = {
   "_id": {
@@ -38,35 +41,58 @@ const route = { data: of({ dataset: dataset }) };
 describe('DatasetDetailComponent', () => {
   let component: DatasetDetailComponent;
   let fixture: ComponentFixture<DatasetDetailComponent>;
+  let location: SpyLocation;
+  let mockRouter = {
+    navigate: jasmine.createSpy('navigate') // Create a spy for the navigate method
+  };
 
   beforeEach(async () => {
     await TestBed.configureTestingModule({
       imports: [
-        RouterTestingModule,
+        RouterTestingModule.withRoutes(
+          [{path: 'samples', component: SamplesComponent}]
+        ),
         HttpClientTestingModule,
       ],
       declarations: [ DatasetDetailComponent ],
       // https://testing-angular.com/testing-components-with-children/#unit-test
       schemas: [ CUSTOM_ELEMENTS_SCHEMA ],
       providers: [
         { provide: ActivatedRoute, useValue: route },
+        { provide: Location, useClass: SpyLocation },
+        { provide: Router, useValue: mockRouter },
       ]
     })
     .compileComponents();
 
     fixture = TestBed.createComponent(DatasetDetailComponent);
     component = fixture.componentInstance;
+    location = <SpyLocation>TestBed.inject(Location);
     fixture.detectChanges();
   });
 
   it('should create', () => {
     expect(component).toBeTruthy();
   });
 
-  describe('ngOnInit', () => {
-    it('should get dataset data', () => {
-      component.ngOnInit();
-      expect(component.dataset).toEqual(dataset);
-    });
+  it('should get dataset data', () => {
+    component.ngOnInit();
+    expect(component.dataset).toEqual(dataset);
   });
+
+  // https://codeutility.org/unit-testing-angular-6-location-go-back-stack-overflow/
+  it('should go back to previous page on back button click', () => {
+    spyOn(location, 'back');
+    component.goBack();
+    expect(location.back).toHaveBeenCalled();
+  });
+
+  it('should navigate to /samples with query params when getSamples is called', () => {
+    component.getSamples();
+    expect(mockRouter.navigate).toHaveBeenCalledWith(
+      ['/samples'],
+      { queryParams: { dataset: component.dataset._id.$oid, species: component.dataset.species } }
+    );
+  });
+
 });