How to Order NUnit Tests

nunit

More than once the question has been asked on SO. But the only answers that are given read "you should not need to order your unit tests, it is bad because" or "you can avoid that if…"

I already know it is bad, why it is bad, and techniques to avoid it. But that is not what I want to know. I'd like to know if it is possible to order the execution of NUnit tests, other than an alphabetical order. To be blunt: I actually want state to propogate from one test to the next. Trust me that I have a clever reason for this, that defies the usual philosophy.

MSTest has the "ordered test" capability, which is very useful in certain cases. I'd like to have that ability in NUnit. Can it be done?

Best Answer

Update for NUnit 3.2.0 - now it support OrderAttribute.

The OrderAttribute may be placed on a test method to specify the order in which tests are run. Example:

public class MyFixture
{
    [Test, Order(1)]
    public void TestA() { ... }


    [Test, Order(2)]
    public void TestB() { ... }

    [Test]
    public void TestC() { ... }
}

https://github.com/nunit/docs/wiki/Order-Attribute

Related Solutions

C# – How to test database-related code with NUnit

NUnit now has a [Rollback] attribute, but I prefer to do it a different way. I use the TransactionScope class. There are a couple of ways to use it.

[Test]
public void YourTest() 
{
    using (TransactionScope scope = new TransactionScope())
    {
        // your test code here
    }
}

Since you didn't tell the TransactionScope to commit it will rollback automatically. It works even if an assertion fails or some other exception is thrown.

The other way is to use the [SetUp] to create the TransactionScope and [TearDown] to call Dispose on it. It cuts out some code duplication, but accomplishes the same thing.

[TestFixture]
public class YourFixture
{
    private TransactionScope scope;

    [SetUp]
    public void SetUp()
    {
        scope = new TransactionScope();
    }

    [TearDown]
    public void TearDown()
    {
        scope.Dispose();
    }


    [Test]
    public void YourTest() 
    {
        // your test code here
    }
}

This is as safe as the using statement in an individual test because NUnit will guarantee that TearDown is called.

Having said all that I do think that tests that hit the database are not really unit tests. I still write them, but I think of them as integration tests. I still see them as providing value. One place I use them often is in testing LINQ to SQL code. I don't use the designer. I hand write the DTO's and attributes. I've been known to get it wrong. The integration tests help catch my mistake.

C# – How to run NUnit in debug mode from Visual Studio

When I need to debug my NUnit tests, I simply attach to the NUnit GUI application nunit-agent.exe using "Debug|Attach to Process" and run the tests from the GUI. Any breakpoints in my tests (or the code they're testing) are hit. Am I misunderstanding your question, or will that work for you?

Best Answer

Related Solutions

C# – How to test database-related code with NUnit

C# – How to run NUnit in debug mode from Visual Studio

Related Topic