add unit tests

src/app/services/user/user-song-usage.service.spec.ts

@@ -0,0 +1,76 @@
+import {TestBed} from '@angular/core/testing';
+import {of} from 'rxjs';
+import {DbService} from '../db.service';
+import {ShowDataService} from '../../modules/shows/services/show-data.service';
+import {ShowSongDataService} from '../../modules/shows/services/show-song-data.service';
+import {UserSessionService} from './user-session.service';
+import {UserSongUsageService} from './user-song-usage.service';
+
+describe('UserSongUsageService', () => {
+  let service: UserSongUsageService;
+  let dbServiceSpy: jasmine.SpyObj<DbService>;
+  let sessionSpy: jasmine.SpyObj<UserSessionService>;
+  let showDataServiceSpy: jasmine.SpyObj<ShowDataService>;
+  let showSongDataServiceSpy: jasmine.SpyObj<ShowSongDataService>;
+
+  beforeEach(() => {
+    dbServiceSpy = jasmine.createSpyObj<DbService>('DbService', ['doc']);
+    sessionSpy = jasmine.createSpyObj<UserSessionService>('UserSessionService', ['update$'], {
+      user$: of({id: 'user-1', role: 'admin', songUsage: {}}) as never,
+      users$: of([{id: 'user-1'}, {id: 'user-2'}]) as never,
+    });
+    showDataServiceSpy = jasmine.createSpyObj<ShowDataService>('ShowDataService', ['listRaw$']);
+    showSongDataServiceSpy = jasmine.createSpyObj<ShowSongDataService>('ShowSongDataService', ['list$']);
+
+    sessionSpy.update$.and.resolveTo();
+    showDataServiceSpy.listRaw$.and.returnValue(of([{id: 'show-1', owner: 'user-1'}, {id: 'show-2', owner: 'user-2'}] as never));
+    showSongDataServiceSpy.list$.and.callFake((showId: string) =>
+      of(showId === 'show-1' ? ([{songId: 'song-1'}, {songId: 'song-1'}, {songId: 'song-2'}] as never) : ([{songId: 'song-3'}] as never))
+    );
+    dbServiceSpy.doc.and.returnValue({update: jasmine.createSpy('update').and.resolveTo()} as never);
+
+    void TestBed.configureTestingModule({
+      providers: [
+        {provide: DbService, useValue: dbServiceSpy},
+        {provide: UserSessionService, useValue: sessionSpy},
+        {provide: ShowDataService, useValue: showDataServiceSpy},
+        {provide: ShowSongDataService, useValue: showSongDataServiceSpy},
+      ],
+    });
+
+    service = TestBed.inject(UserSongUsageService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+
+  it('should increment and decrement song usage for the current user', async () => {
+    const updateSpy = jasmine.createSpy('update').and.resolveTo();
+    dbServiceSpy.doc.and.returnValue({update: updateSpy} as never);
+
+    await service.incSongCount('song-1');
+    await service.decSongCount('song-2');
+
+    expect(dbServiceSpy.doc).toHaveBeenCalledWith('users/user-1');
+    expect(updateSpy.calls.argsFor(0)[0]).toEqual({'songUsage.song-1': jasmine.anything()});
+    expect(updateSpy.calls.argsFor(1)[0]).toEqual({'songUsage.song-2': jasmine.anything()});
+  });
+
+  it('should rebuild song usage for all users based on owned show songs', async () => {
+    await expectAsync(service.rebuildSongUsage()).toBeResolvedTo({
+      usersProcessed: 2,
+      showsProcessed: 2,
+      showSongsProcessed: 4,
+    });
+
+    expect(sessionSpy.update$).toHaveBeenCalledWith('user-1', {songUsage: {'song-1': 2, 'song-2': 1}});
+    expect(sessionSpy.update$).toHaveBeenCalledWith('user-2', {songUsage: {'song-3': 1}});
+  });
+
+  it('should reject song usage rebuilds for non-admin users', async () => {
+    Object.defineProperty(sessionSpy, 'user$', {value: of({id: 'user-1', role: 'leader'})});
+
+    await expectAsync(service.rebuildSongUsage()).toBeRejectedWithError('Admin role required to rebuild songUsage.');
+  });
+});