How to set the test case sequence in xUnit

问题:

I have written the xUnit test cases in C#. That test class contains so many methods. I need to run the whole test cases in a sequence. How can I set the test case sequence in xUnit?

回答1:

In xUnit 2.* this can be achieved using the TestCaseOrderer attribute to designate an ordering strategy, which can be used to reference an attribute that is annotated on each test to denote an order.

For example:

Ordering Strategy

public class PriorityOrderer : ITestCaseOrderer
{
    public IEnumerable<TTestCase> OrderTestCases<TTestCase>(IEnumerable<TTestCase> testCases) where TTestCase : ITestCase
    {
        var sortedMethods = new SortedDictionary<int, List<TTestCase>>();

        foreach (TTestCase testCase in testCases)
        {
            int priority = 0;

            foreach (IAttributeInfo attr in testCase.TestMethod.Method.GetCustomAttributes((typeof(TestPriorityAttribute).AssemblyQualifiedName)))
                priority = attr.GetNamedArgument<int>("Priority");

            GetOrCreate(sortedMethods, priority).Add(testCase);
        }

        foreach (var list in sortedMethods.Keys.Select(priority => sortedMethods[priority]))
        {
            list.Sort((x, y) => StringComparer.OrdinalIgnoreCase.Compare(x.TestMethod.Method.Name, y.TestMethod.Method.Name));
            foreach (TTestCase testCase in list)
                yield return testCase;
        }
    }

    static TValue GetOrCreate<TKey, TValue>(IDictionary<TKey, TValue> dictionary, TKey key) where TValue : new()
    {
        TValue result;

        if (dictionary.TryGetValue(key, out result)) return result;

        result = new TValue();
        dictionary[key] = result;

        return result;
    }
}

Attribute

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
public class TestPriorityAttribute : Attribute
{
    public TestPriorityAttribute(int priority)
    {
        Priority = priority;
    }

    public int Priority { get; private set; }
}

Test Cases

[TestCaseOrderer("FullNameOfOrderStrategyHere", "OrderStrategyAssemblyName")]
public class PriorityOrderExamples
{
    [Fact, TestPriority(5)]
    public void Test3()
    {
        //called third
    }

    [Fact, TestPriority(0)]
    public void Test2()
    {
      //called second
    }

    [Fact, TestPriority(-5)]
    public void Test1()
    {
       // called first
    }

}

xUnit 2.* ordering samples here

回答2:

Testpriority: at the bottom of this page.

[PrioritizedFixture]
public class MyTests
{
    [Fact, TestPriority(1)]
    public void FirstTest()
    {
        // Test code here is always run first
    }
    [Fact, TestPriority(2)]
    public void SeccondTest()
    {
        // Test code here is run second
    }
}

BTW, I have the same problem right now. And yes, it is not the clean art.. but QA wanted a manual test.. so an automated test with a specific order already is a big leap for them.. (cough) and yes, it is not really unit testing..

回答3:

You can't, by design. It's deliberately random in order to prevent anyone getting one of those either by desire or by accident.

The randomness is only for a given Test class, so you may be able to achieve your goals by wrapping items you want to control the order of inside a nested class - but in that case, you'll still end up with random order whenever you have more than two Test Methods in a class.

If you're trying to manage the building up of fixtures or context, the built-in IUseFixture<T> mechanism may be appropriate. See the xUnit Cheat Sheet for examples.

But you really need to tell us more about what you're trying to do or we'll just have to get speculative.