test(api): ✅ Add unit test for searching movies

apps/api/src/movies/movies-search-db/movies-search.db.service.spec.ts

@@ -1,21 +1,71 @@
 import { Test, TestingModule } from '@nestjs/testing'
+import { createMock } from '@golevelup/ts-jest'
 
+import { movieFactory } from '../../database/factories/movie'
 import { PrismaService } from '../../database/prisma.service'
+import { movieTitleFactory } from '../../database/factories/movieTitle'
 
 import { MoviesSearchDbService } from './movies-search-db.service'
 
 describe('MoviesSearchDbService', () => {
   let service: MoviesSearchDbService
 
-  beforeEach(async () => {
-    const module: TestingModule = await Test.createTestingModule({
+  let module: TestingModule
+  let prismaService: PrismaService
+
+  beforeAll(async () => {
+    module = await Test.createTestingModule({
       providers: [MoviesSearchDbService, PrismaService]
-    }).compile()
+    })
+      .useMocker(createMock)
+      .compile()
 
     service = module.get<MoviesSearchDbService>(MoviesSearchDbService)
+    prismaService = module.get<PrismaService>(PrismaService)
+  })
+
+  it.only('should call the database with the search title', async () => {
+    const queryRawSpy = jest.spyOn(prismaService, '$queryRaw').mockResolvedValueOnce([])
+
+    const title = 'Any Title'
+    await service.findByTitle(title)
+
+    const queryRawCalls = queryRawSpy.mock.calls[0][0]
+
+    const queryRawCallsString = (queryRawCalls as unknown as string[]).map(elem => elem.replace(/\s+/g, ' ')).join(' ')
+
+    const expectedSqlQuery = ' SELECT m.*, t.* FROM "Movie" m ' +
+      'JOIN "MovieTitle" t ON m.id = t."movieId" ' +
+      'WHERE t.title %   ORDER BY similarity(t.title,  ) DESC LIMIT  ;'
+    expect(queryRawSpy).toHaveBeenCalledWith(
+      [expect.any(String), expect.any(String), expect.any(String), expect.any(String)],
+      title, title, 10)
+
+    expect(queryRawCallsString).toBe(expectedSqlQuery)
+  })
+
+  it('should handle empty results from the database', async () => {
+    jest.spyOn(prismaService, '$queryRaw').mockResolvedValueOnce([])
+
+    const results = await service.findByTitle('Nonexistent Movie')
+
+    expect(results).toEqual([])
   })
 
-  it('should be defined', () => {
-    expect(service).toBeDefined()
+  it('should handle database errors by throwing', async () => {
+    jest.spyOn(prismaService, '$queryRaw').mockRejectedValueOnce(new Error('Database error'))
+
+    await expect(service.findByTitle('The Matrix')).rejects.toThrow('Database error')
+  })
+
+  it('should post-process data correctly', async () => {
+    const mockMovieData = movieFactory.build()
+    const mockMovieTitleData = movieTitleFactory.build()
+
+    jest.spyOn(prismaService, '$queryRaw').mockResolvedValueOnce([{ ...mockMovieData, ...mockMovieTitleData }])
+
+    const result = await service.findByTitle('Mock Title')
+
+    expect(result).toEqual([{ ...mockMovieData, movieTitles: [mockMovieTitleData] }])
   })
 })