public async Task CheckIfPartExists() { //Arrange var dbOptions = new DbContextOptionsBuilder <HyperCarsDbContext>() .UseInMemoryDatabase("HyperCarsDb") .Options; var db = new HyperCarsDbContext(dbOptions); var partService = new PartService(db); var part = new Part { Id = 1, Name = "Test1" }; db.AddRange(part); await db.SaveChangesAsync(); //Act var result = partService.Exists(1); //Assert result.Equals(true); }