NUnit testcasesource with data refactored into another class

Question

I am using NUnit with the TestCaseSource attribute to do data-driven testing with dynamic data in the same approach as NUnit TestCaseSource pass value to factory and How can I pass dynamic objects into an NUnit TestCase function?

In each case they use IEnumerable<TestCaseData> to specify data. It appears from the NUnit documentation here http://nunit.org/index.php?p=testCaseSource&r=2.5 that this needs to be a static or instance member of the same class as the TestCase.

I would like to refactor this into another class since I want to use the same TestCaseSource attribute. Does anyone know if this is possible?

score 23 · Answer 1 · edited Aug 26 '16 at 12:24

Robert already answered it, but I will try to improve his answer with the new features of C#.

public static class TestCasesData 
{ 
      private static string[] TestStringsData() 
      {
           return new string[] {"TEST1", "TEST2"};
      }
      private static string[] TestIntsData() 
      {
           return new in[] { 1, 2};
      }
}
[TestFixture]
public class MyTest
{
    [Test]
    [TestCaseSource(typeof(TestCasesData ), nameof(TestCasesData .TestStringsData))]
    public void TestCase1(...)
    {
    }

    [Test]
    public void TestCase2(
      [ValueSource(typeof(TestCasesData), "TestIntsData")] int testData,
    )
    {
    }
}

+1 using `nameof` is better than magic strings. If class or method name changes, compiler will redflag it here. — Nikhil Agrawal, Nov 03 '17 at 06:55

Robert Gowland · Answer 2 · 2018-05-28T17:27:45.020

11

You can do something like:

[TestCaseSource(typeof(CommonSource), "GetData")]
public void MyTest(...) {...}

The first argument to the attribute constructor tells it which class to look in and the second argument tell it the specific member name to use.

edited May 28 '18 at 17:27

answered May 13 '16 at 18:38

Robert Gowland

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score 3 · Answer 3 · answered Jun 07 '11 at 14:34

If NUnit requires the TestCaseSource to be in the same class as the tests, the easiest way might be to have that method call your common method. Then, the details can be kept elsewhere, so you minimize duplicate code.

For example, each test class might have the following:

IEnumerable LocalSource()
{
    return CommonSource.GetData();
}

The CommonSource class would be a separate class that loads the data necessary for the tests.

NUnit testcasesource with data refactored into another class

3 Answers3