NUnit Test Run Order

Question

By default nunit tests run alphabetically. Does anyone know of any way to set the execution order? Does an attribute exist for this?

Answer 1

If you are using [TestCase], the argument TestName provides a name for the test.

If not specified, a name is generated based on the method name and the arguments provided.

You can control the order of test execution as given below:

                    [Test]
            [TestCase("value1", TestName = "ExpressionTest_1")]
            [TestCase("value2", TestName = "ExpressionTest_2")]
            [TestCase("value3", TestName = "ExpressionTest_3")]
            public void ExpressionTest(string  v)
            {
                //do your stuff
            }

Here i used the method name "ExpressionTest" suffix with a number.

You can use any names ordered alphabetical see TestCase Attribute

Answer 2

I really like the previous answer.

I changed it a little to be able to use an attribute to set the order range:

namespace SmiMobile.Web.Selenium.Tests
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Reflection;
    using NUnit.Framework;

    public class OrderedTestAttribute : Attribute
    {
        public int Order { get; set; }


        public OrderedTestAttribute(int order)
        {
            Order = order;
        }
    }

    public class TestStructure
    {
        public Action Test;
    }

    class Int
    {
        public int I;
    }

    [TestFixture]
    public class ControllingTestOrder
    {
        private static readonly Int MyInt = new Int();

        [TestFixtureSetUp]
        public void SetUp()
        {
            MyInt.I = 0;
        }

        [OrderedTest(0)]
        public void Test0()
        {
            Console.WriteLine("This is test zero");
            Assert.That(MyInt.I, Is.EqualTo(0));
        }

        [OrderedTest(2)]
        public void ATest0()
        {
            Console.WriteLine("This is test two");
            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(2));
        }


        [OrderedTest(1)]
        public void BTest0()
        {
            Console.WriteLine("This is test one");
            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(1));
        }

        [OrderedTest(3)]
        public void AAA()
        {
            Console.WriteLine("This is test three");
            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(3));
        }


        [TestCaseSource(sourceName: "TestSource")]
        public void MyTest(TestStructure test)
        {
            test.Test();
        }

        public IEnumerable<TestCaseData> TestSource
        {
            get
            {
                var assembly =Assembly.GetExecutingAssembly();
                Dictionary<int, List<MethodInfo>> methods = assembly
                    .GetTypes()
                    .SelectMany(x => x.GetMethods())
                    .Where(y => y.GetCustomAttributes().OfType<OrderedTestAttribute>().Any())
                    .GroupBy(z => z.GetCustomAttribute<OrderedTestAttribute>().Order)
                    .ToDictionary(gdc => gdc.Key, gdc => gdc.ToList());

                foreach (var order in methods.Keys.OrderBy(x => x))
                {
                    foreach (var methodInfo in methods[order])
                    {
                        MethodInfo info = methodInfo;
                        yield return new TestCaseData(
                            new TestStructure
                                {
                                    Test = () =>
                                        {
                                            object classInstance = Activator.CreateInstance(info.DeclaringType, null);
                                            info.Invoke(classInstance, null);
                                        }
                                }).SetName(methodInfo.Name);
                    }
                }

            }
        }
    }
}

Answer 3

Regardless of whether or not Tests are order dependent... some of us just want to control everything, in an orderly fashion.

Unit tests are usually created in order of complexity. So, why shouldn't they also be run in order of complexity, or the order in which they were created?

Personally, I like to see the tests run in the order of which I created them. In TDD, each successive test is naturally going to be more complex, and take more time to run. I would rather see the simpler test fail first as it will be a better indicator as to the cause of the failure.

But, I can also see the benefit of running them in random order, especially if you want to test that your tests don't have any dependencies on other tests. How about adding an option to test runners to "Run Tests Randomly Until Stopped"?

Answer 4

You should not depend on the order in which the test framework picks tests for execution. Tests should be isolated and independent. In that they should not depend on some other test setting the stage for them or cleaning up after them. They should also produce the same result irrespective of the order of the execution of tests (for a given snapshot of the SUT)

I did a bit of googling. As usual, some people have resorted to sneaky tricks (instead of solving the underlying testability/design issue

• naming the tests in an alphabetically ordered manner such that tests appear in the order they 'need' to be executed. However NUnit may choose to change this behavior with a later release and then your tests would be hosed. Better check in the current NUnit binaries to Source Control.
• VS (IMHO encouraging the wrong behavior with their 'agile tools') has something called as "Ordered tests" in their MS testing framework. I didn't waste any time reading up but it seems to be targeted towards the same audience

See Also: characteristics of a good test

Answer 5

Wanting the tests to run in a specific order does not mean that the tests are dependent on each other - I'm working on a TDD project at the moment, and being a good TDDer I've mocked/stubbed everything, but it would make it more readable if I could specify the order which the tests results are displayed - thematically instead of alphabetically. So far the only thing I can think of is to prepend a_ b_ c_ to classes to classes, namespaces and methods. (Not nice) I think a [TestOrderAttribute] attribute would be nice - not stricly followed by the framework, but a hint so we can achieve this

Answer 6

I know this is a relatively old post, but here is another way to keep your test in order WITHOUT making the test names awkward. By using the TestCaseSource attribute and having the object you pass in have a delegate (Action), you can totally not only control the order but also name the test what it is.

This works because, according to the documentation, the items in the collection returned from the test source will always execute in the order they are listed.

Here is a demo from a presentation I'm giving tomorrow:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NUnit.Framework;

namespace NUnitTest
{
    public class TestStructure
    {
        public Action Test;
    }

    class Int
    {
        public int I;
    }

    [TestFixture]
    public class ControllingTestOrder
    {
        private static readonly Int MyInt= new Int();

        [TestFixtureSetUp]
        public void SetUp()
        {
            MyInt.I = 0;
        }

        [TestCaseSource(sourceName: "TestSource")]
        public void MyTest(TestStructure test)
        {
            test.Test();
        }

        public IEnumerable<TestCaseData> TestSource
        {
            get
            {
                yield return new TestCaseData(
                    new TestStructure
                    {
                        Test = () =>
                        {
                            Console.WriteLine("This is test one");
                            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(1));
                        }
                    }).SetName(@"Test One");
                yield return new TestCaseData(
                    new TestStructure
                    {
                        Test = () =>
                        {
                            Console.WriteLine("This is test two");
                            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(2));
                        }
                    }).SetName(@"Test Two");
                yield return new TestCaseData(
                    new TestStructure
                    {
                        Test = () =>
                        {
                            Console.WriteLine("This is test three");
                            MyInt.I++; Assert.That(MyInt.I, Is.EqualTo(3));
                        }
                    }).SetName(@"Test Three");
            }
        }
    }
}