Readable unit testing of a yielded sequence?

Question

Let's suppose I have some method that returns a IEnumerable<int> object. This methods make use of yield return keyword to produce a infinite sequence. Example of the Fibonacci algorithm :

public static IEnumerable<long> Fibonacci()
{
    long x = 0L;
    long y = 1L;
    long z;
    yield return x;
    yield return y;
    while (true)
    {
        z = x + y;
        yield return z;
        y = x;
        x = z;
    }
}

How can I properly create unit test for such sequence ? By proper I also mean readable.

I can write unit tests like this :

[TestMethod]
public void FibonacciTest()
{
    var actual = MyClass.Fibonacci();

    var @enum = actual.GetEnumerator();

    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 0);
    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 1);
    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 1);
    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 2);
    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 3);
    Assert.IsTrue(@enum.MoveNext();
    Assert.AreEqual(@enum.Current), 5);
    Assert.IsTrue(@enum.MoveNext();
}

This test works, but I don't think it is readable. What are general (Fibonacci alogrithm was only a example) guidelines for writing unit tests for sequences ?

PS: I'm using Visual Studio OOB Test suite + Pex.

Answer 1

CollectionAssert.AreEqual(new[] {0,1,1,2,3,5}, MyClass.Fibonacci().Take(6).ToList());