Skip to main content

Unit test classes - using a base class

Mai mult ca sigur cu toții am scris teste. 1,2, 3 .. n clase de teste. Într-un anumit moment ajungem sa dorim sa refactorizam codul, iar o parte din logica (setup-ul testelor) sa îl ducem în clasa de baza.
public class Test1: BaseTest
{
    [TestMethod]
    public void Method1Test()
    {
        Console.WriteLine("Method1Test");
    }

    [TestInitialize]
    public void TestInit()
    {
        Console.WriteLine("TestInitialize");
    }
   
    [TestCleanup]
    public void TestCleanup()
    {
        Console.WriteLine("TestCleanup");
    }
   
    [ClassInitialize]
    public static void ClassInit(TestContext testContext)
    {
        Console.WriteLine("ClassInit");
    }      
}
Sa ne uitam acuma la clasa de baza:
public class BaseTest{   
    [TestInitialize]
    public void BaseTestInit()
    {
        Console.WriteLine("BaseTestInitialize");
    }
   
    [TestCleanup]
    public void BaseTestCleanup()
    {
        Console.WriteLine("BaseTestCleanup");
    }
   
    [ClassInitialize]
    public static void BaseClassInit(TestContext testContext)
    {
        Console.WriteLine("BaseClassInit");
    }      
}
Totul pare in regula, in mod normal la rularea testului va asteptati sa ruleze in felul urmator:
  • BaseClassInit
  • ClassInit
  • BaseTestInit
  • TestInit
  • Method1Test
  • TestCleanup
Dar o sa avem parte de o surpriza:
  • ClassInit
  • BaseTestInit
  • TestInit
  • Method1Test
  • TestCleanup
BaseClassInit nu a fost apelat. Chiar dacă ne-am aștepta ca metoda din clasa de baza sa fie apelata, iar în alte framework-uri este suportat (NUnit) acest comportament, M$ nu ne prea ajuta în acest caz.
La aceasta problema eu am văzut 3 posibile soluții, de la caz la caz ele pot sa fie aplicate sau nu:
  1. clasa de teste care mosteneste clasa de baza sa apeleze explicit BaseClassInit. Dar acest lucru ne obliga avem o metoda decorata cu ClassInitialize in fiecare clasa derivata (poate nu ne dorim acest lucru);
  2. in unele situații, putem sa mutam logica din BaseClassInit în constructorul static:
static BaseTest()
{
    Console.WriteLine("BaseClassInit");
}
      3.  prin reflection putem sa facem un hook si sa ne implementam noi acest mecanism. Dar este destul de complex si nu cred ca merita;
Din fericire avem cateva solutii la indemana, dar uneori dupa o refactorizare ne putem trezi ca ne cad testele si sa nu gasim cauza exacta.

Comments

  1. Mi se pare normal ceea ce se întîmplă acolo. În momentul în care iterezi cu reflection prin clasa derivată o să vezi (în mod natural) doar metodele clasei derivate. Nu e M$ de vină, lucrurile sunt la fel implementate și în Java.

    ReplyDelete
  2. http://www.nunit.org/index.php?p=fixtureSetup&r=2.5.7
    La NUnit, nu este nevoie ca metoda sa fie statica, din aceasta cauza problema se rezolva destul de simplu.

    ReplyDelete

Post a Comment

Popular posts from this blog

Windows Docker Containers can make WIN32 API calls, use COM and ASP.NET WebForms

After the last post , I received two interesting questions related to Docker and Windows. People were interested if we do Win32 API calls from a Docker container and if there is support for COM. WIN32 Support To test calls to WIN32 API, let’s try to populate SYSTEM_INFO class. [StructLayout(LayoutKind.Sequential)] public struct SYSTEM_INFO { public uint dwOemId; public uint dwPageSize; public uint lpMinimumApplicationAddress; public uint lpMaximumApplicationAddress; public uint dwActiveProcessorMask; public uint dwNumberOfProcessors; public uint dwProcessorType; public uint dwAllocationGranularity; public uint dwProcessorLevel; public uint dwProcessorRevision; } ... [DllImport("kernel32")] static extern void GetSystemInfo(ref SYSTEM_INFO pSI); ... SYSTEM_INFO pSI = new SYSTEM_INFO(

Azure AD and AWS Cognito side-by-side

In the last few weeks, I was involved in multiple opportunities on Microsoft Azure and Amazon, where we had to analyse AWS Cognito, Azure AD and other solutions that are available on the market. I decided to consolidate in one post all features and differences that I identified for both of them that we should need to take into account. Take into account that Azure AD is an identity and access management services well integrated with Microsoft stack. In comparison, AWS Cognito is just a user sign-up, sign-in and access control and nothing more. The focus is not on the main features, is more on small things that can make a difference when you want to decide where we want to store and manage our users.  This information might be useful in the future when we need to decide where we want to keep and manage our users.  Feature Azure AD (B2C, B2C) AWS Cognito Access token lifetime Default 1h – the value is configurable 1h – cannot be modified

What to do when you hit the throughput limits of Azure Storage (Blobs)

In this post we will talk about how we can detect when we hit a throughput limit of Azure Storage and what we can do in that moment. Context If we take a look on Scalability Targets of Azure Storage ( https://azure.microsoft.com/en-us/documentation/articles/storage-scalability-targets/ ) we will observe that the limits are prety high. But, based on our business logic we can end up at this limits. If you create a system that is hitted by a high number of device, you can hit easily the total number of requests rate that can be done on a Storage Account. This limits on Azure is 20.000 IOPS (entities or messages per second) where (and this is very important) the size of the request is 1KB. Normally, if you make a load tests where 20.000 clients will hit different blobs storages from the same Azure Storage Account, this limits can be reached. How we can detect this problem? From client, we can detect that this limits was reached based on the HTTP error code that is returned by HTTP