public async void IsOptionExistedById_ShouldReturnBool() { // Arrange //create in memory options var options = new DbContextOptionsBuilder <DataBaseContext>() .UseInMemoryDatabase(databaseName: "IsOptionExistedById_ShouldReturnBool") .Options; using (var context = new DataBaseContext(options)) { await context.AddRangeAsync(optionsList); await context.SaveChangesAsync(); Assert.Equal(2, await context.ProductOption.CountAsync()); } // Act using (var context = new DataBaseContext(options)) { var repo = new OptionRepository(context); var result = await repo.IsOptionExistedById(firstOption.Id); Assert.Equal(true, result); } using (var context = new DataBaseContext(options)) { var repo = new OptionRepository(context); var result = await repo.IsOptionExistedById(Guid.NewGuid()); Assert.Equal(false, result); } }