108588: Fixed browse by date tab's year dropdown always being empty

- The data passed to the injector in BrowseByComponent was not updated by ngOnChanges
- Also refactored the injector logic to StartsWithLoaderComponent

src/app/shared/starts-with/starts-with-loader.component.spec.ts

@@ -0,0 +1,71 @@
+import { StartsWithLoaderComponent } from './starts-with-loader.component';
+import { ComponentFixture, TestBed, waitForAsync } from '@angular/core/testing';
+import { ChangeDetectionStrategy, NO_ERRORS_SCHEMA } from '@angular/core';
+import { DynamicComponentLoaderDirective } from '../abstract-component-loader/dynamic-component-loader.directive';
+import { TranslateModule } from '@ngx-translate/core';
+import { StartsWithTextComponent } from './text/starts-with-text.component';
+import { Router, ActivatedRoute } from '@angular/router';
+import { RouterStub } from '../testing/router.stub';
+import { ThemeService } from '../theme-support/theme.service';
+import { getMockThemeService } from '../mocks/theme-service.mock';
+import { StartsWithType } from './starts-with-decorator';
+import { ActivatedRouteStub } from '../testing/active-router.stub';
+import { PaginationService } from '../../core/pagination/pagination.service';
+import { PaginationServiceStub } from '../testing/pagination-service.stub';
+
+describe('StartsWithLoaderComponent', () => {
+  let comp: StartsWithLoaderComponent;
+  let fixture: ComponentFixture<StartsWithLoaderComponent>;
+
+  let paginationService: PaginationServiceStub;
+  let route: ActivatedRouteStub;
+  let themeService: ThemeService;
+
+  const type: StartsWithType = StartsWithType.text;
+
+  beforeEach(waitForAsync(() => {
+    paginationService = new PaginationServiceStub();
+    route = new ActivatedRouteStub();
+    themeService = getMockThemeService('dspace');
+
+    void TestBed.configureTestingModule({
+      imports: [
+        TranslateModule.forRoot(),
+      ],
+      declarations: [
+        StartsWithLoaderComponent,
+        StartsWithTextComponent,
+        DynamicComponentLoaderDirective,
+      ],
+      providers: [
+        { provide: PaginationService, useValue: paginationService },
+        { provide: ActivatedRoute, useValue: route },
+        { provide: Router, useValue: new RouterStub() },
+        { provide: ThemeService, useValue: themeService },
+      ],
+      schemas: [NO_ERRORS_SCHEMA],
+    }).overrideComponent(StartsWithLoaderComponent, {
+      set: {
+        changeDetection: ChangeDetectionStrategy.Default,
+        entryComponents: [StartsWithTextComponent],
+      }
+    }).compileComponents();
+  }));
+
+  beforeEach(waitForAsync(() => {
+    fixture = TestBed.createComponent(StartsWithLoaderComponent);
+    comp = fixture.componentInstance;
+    comp.type = type;
+    comp.paginationId = 'bbm';
+    comp.startsWithOptions = [];
+    spyOn(comp, 'getComponent').and.returnValue(StartsWithTextComponent);
+
+    fixture.detectChanges();
+  }));
+
+  describe('When the component is rendered', () => {
+    it('should call the getComponent function', () => {
+      expect(comp.getComponent).toHaveBeenCalled();
+    });
+  });
+});