public async Task GetByCategoryIdShouldReturnOnlyTheCategory() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options; AutoMapperConfig.RegisterMappings(Assembly.Load("CookingBook.Web.ViewModels")); var dbContext = new ApplicationDbContext(options); var category = new Category(); var nutrValue = new NutritionValue(); var user = new ApplicationUser(); var prod = new Collection <RecipeByIdProductsViewModel>(); dbContext.Recipes.Add(new Recipe { Id = "a", CreatedOn = DateTime.Parse("2008-11-01T19:31:00.0000000Z"), Title = "newTitle1", CategoryId = 1, }); dbContext.Recipes.Add(new Recipe { Id = "b", CreatedOn = DateTime.Parse("2008-11-01T19:32:00.0000000Z"), Title = "newTitle2", CategoryId = 1, }); dbContext.Recipes.Add(new Recipe { Id = "c", CreatedOn = DateTime.Parse("2008-11-01T19:33:00.0000000Z"), Title = "newTitle3", CategoryId = 2, }); dbContext.Recipes.Add(new Recipe { Id = "d", CreatedOn = DateTime.Parse("2008-11-01T19:34:00.0000000Z"), Title = "newTitle4", CategoryId = 3, }); dbContext.Recipes.Add(new Recipe { Id = "e", CreatedOn = DateTime.Parse("2008-11-01T19:35:00.0000000Z"), Title = "newTitle5", CategoryId = 4, }); dbContext.Recipes.Add(new Recipe { Id = "f", CreatedOn = DateTime.Parse("2008-11-01T19:36:00.0000000Z"), Title = "newTitle6", CategoryId = 4, }); dbContext.Recipes.Add(new Recipe { Id = "g", CreatedOn = DateTime.Parse("2008-11-01T19:37:00.0000000Z"), Title = "newTitle7", CategoryId = 4, }); dbContext.Recipes.Add(new Recipe { Id = "h", CreatedOn = DateTime.Parse("2008-11-01T19:38:00.0000000Z"), Title = "newTitle8", CategoryId = 4, }); await dbContext.SaveChangesAsync(); var recipeRepo = new EfDeletableEntityRepository <Recipe>(dbContext); var nutritionRepo = new EfDeletableEntityRepository <NutritionValue>(dbContext); var productRepo = new EfDeletableEntityRepository <Product>(dbContext); var userRepo = new EfDeletableEntityRepository <ApplicationUser>(dbContext); var service = new RecipesService(recipeRepo, nutritionRepo, productRepo, userRepo); Assert.Equal(4, service.GetByCategoryId <RecipeDTO>(4).Count()); }