public void Lag_WithTestCases_ProducesCorrectResults(string collectionString, int amount, string expectedString)
{
int[] collection = collectionString.Split(',').Where(s => !string.IsNullOrWhiteSpace(s)).Select(int.Parse).ToArray();
var output = CollectionExtensions.Lag(collection, amount);
var outputString = string.Join(",", output.Select(item => $"({item.Element},{item.LaggingElement})"));
Assert.That(outputString, Is.EqualTo(expectedString));
}
public void Lag_NullCollection_ThrowsArgumentNullException()
{
IEnumerable <int> collection = null;
Assert.Throws <ArgumentNullException>(() => CollectionExtensions.Lag(collection));
}
public void Lag_NegativeAmount_ThrowsArgumentOutOfRangeException()
{
IEnumerable <int> collection = Enumerable.Range(0, 10);
Assert.Throws <ArgumentOutOfRangeException>(() => CollectionExtensions.Lag(collection, -1));
}