Test parameterization in xUnit.net similar to NUnit

xUnit offers a way to run parameterized tests through something called data theories. The concept is equivalent to the one found in NUnit but the functionality you get out of the box is not as complete.

Here’s an example:

[Theory]
[InlineData("Foo")]
[InlineData(9)]
[InlineData(true)]
public void Should_be_assigned_different_values(object value)
{
    Assert.NotNull(value);
}

In this example xUnit will run the Should_format_the_currency_value_correctly test once for every InlineDataAttribute each time passing the specified value as argument.

Data theories are an extensibility point that you can use to create new ways to run your parameterized tests. The way this is done is by creating new attributes that inspect and optionally act upon the arguments and return value of the test methods.

You can find a good practical example of how xUnit’s data theories can be extended in AutoFixture’s AutoData and InlineAutoData theories.