NUnit data driven unit test with datasource

Question

I have one data source like -4,-3,-3,-2,-1,0,1,2,2,3,4 , I have one function and this function can capture repeated number for example in this data source we have -3,2 are repeated .The repeated numbers are reported in end of the program. I couldn't find good example(I spent 3 hours). How can I implement a unit test with NUnit that can be test the same situation and it tells me the results, if you have some example , It will be very useful to me.(Really appreciated).

Answer 1

You can use TestCase attributes for simple data like what you've described.

[Test]
[TestCase(new[] { -4, -3, -3, -2, -1, 0, 1, 2, 2, 3, 4 }, new []{-3,2})]
public void YourTest(int[] given, int[] expected)    
{  ... }

Note: ReSharper (at least my version of it) doesn't honor multiple test cases like this one so I had to confirm multiple test cases with the NUnit GUI.

Answer 2

First things first - get a working test. Something like this:

    [Test]
    public void DetectsMinusThreeAndTwo()
    {
        RepeatingDigitsDetector target = new RepeatingDigitsDetector();
        int[] source = new int[] { -4, -3, -3, -2, -1, 0, 1, 2, 2, 3, 4 };
        int[] expected = new int[] { -3, -2 };
        int[] actual = target.GetRepeats(source);
        Assert.AreEqual(expected.Length, actual.Length, "checking lengths");
        for (int i = 0; i < expected.Length; i++)
        {
            Assert.AreEqual(expected[i], actual[i], "checking element {0}", i);
        }
    }

Later, you can start adding in goodies like the TestCase or TestCaseSource attributes. But if you're trying to do TDD (as the tdd tag implies), you need to start with a test.

Answer 3

I would recommend TestCaseSource in this instance. Several tests could make the data harder to read inside the TestCase attribute.

Answer 4

As your test data gets complex, it will be difficult to handle. Consider storing your data in another source such as excel, json or Database.

I personally like storing test data in embedded json files. The package JsonSectionReader provides good support for this.