public async Task AddImageUrlsAsyncShouldAddImageUrls() { var options = new DbContextOptionsBuilder <PhotoparallelDbContext>() .UseInMemoryDatabase(Guid.NewGuid().ToString()) .Options; var dbContext = new PhotoparallelDbContext(options); var productService = new ProductsService(dbContext); var productName = "Canon M50"; dbContext.Products.AddRange(new List <Product> { new Product { Name = productName }, new Product { Name = "Canon EOS200" }, new Product { Name = "Ikan Ms" }, new Product { Name = "canon Ef-M 55-200 lens" }, new Product { Name = "Dji Phantom 4" }, }); await dbContext.SaveChangesAsync(); var productId = dbContext.Products.FirstOrDefault(x => x.Name == productName).Id; var imageUrls = new List <string> { "wwwroot/image1", "wwwroot/image2", "wwwroot/image3" }; await productService.AddImageUrlsAsync(productId, imageUrls); var product = dbContext.Products.FirstOrDefault(x => x.Id == productId); Assert.Equal(3, product.Images.Count); }