如何对返回IEnumerable的方法进行单元测试

Question

Please see the code below:

public IEnumerable<int> Numbers()
{
    yield return 1;
    yield return 2;
    yield return 3;
    yield return 4;
    yield return 5;
}

and the unit test below:

public void GetNumbers()
{
    ClassToTest c = new ClassToTest();
    var expected = 
    var actual = c.Numbers();
    CollectionAssert.AreEqual(expected, actual);
}

I need help populating the line that starts: var expected

Do I have to cast to a list for the assert to work. Please notice that order is important ie the two collections must have numbers in the order of: 1,2,3,4,5.

Please note the code above is not a real test. I have used it to explain my problem.

Answer 1

Try:

ClassToTest c = new ClassToTest();

var expected = int[] { 1, 2, 3, 4, 5 };
var actual = c.Numbers().ToArray();

CollectionAssert.AreEqual(expected, actual);