public void AddImageUrlShouldAddAnImageToMod() { var options = new DbContextOptionsBuilder <ApplicationDbContext>() .UseInMemoryDatabase(databaseName: "AddImageUrlShouldAddAnImageToMod_DB") .Options; var dbContext = new ApplicationDbContext(options); var modService = new ModService(dbContext); string imageUrl = "qweqwe"; var mod = new Mod { MainPicturePath = "asdasd", }; dbContext.Mods.Add(mod); dbContext.SaveChanges(); modService.AddImageUrl(mod.Id, imageUrl); Assert.Equal(imageUrl, mod.MainPicturePath); }