/// <summary>
/// Compares the number of elements in the two collections, if possible.
/// </summary>
/// <param name="x">The first collection.</param>
/// <param name="y">The second collection.</param>
/// <returns><see langword="true"/> when the collections have a mismatching
/// number of elements; otherwise, <see langword="false"/>.</returns>
private static bool HaveMismatchingCounts([NoEnumeration] IEnumerable <T> x, [NoEnumeration] IEnumerable <T> y)
{
#region Contract
Debug.Assert(x != null);
Debug.Assert(y != null);
#endregion
var xcount = Enumerables.TryGetCount(x);
var ycount = Enumerables.TryGetCount(y);
return(xcount != null &&
ycount != null &&
xcount != ycount);
}
public void ShouldThrowArgumentNullException_WhenEnumerableIsNull()
{
// Arrange
IReadOnlyCollection <String> enumerable = null;
// Act
var exception = Record.Exception(() =>
{
Enumerables.TryGetCount(enumerable);
});
// Assert
Assert.IsType <ArgumentNullException>(exception);
}
public void ShouldThrowException_WhenSecondSequenceIsLonger()
{
// Arrange
var first = new[] { "a", "b", "c" };
var second = new[] { 1, 2, 3, 4, 5 };
// Act
var exception = Record.Exception(() =>
{
// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
Enumerables.ZipEqual(first, second, (l, r) => l + r).ToArray();
});
// Assert
Assert.IsAssignableFrom <InvalidOperationException>(exception);
}