/// <summary>
/// For checking that exception was throwing when MoveNext was called
/// </summary>
/// <param name="deferredFunction"></param>
/// <typeparam name="T"></typeparam>
internal static void AssertDeferred <T>(
Func <IEnumerable <int>, IEnumerable <T> > deferredFunction)
{
ThrowingEnumerable source = new ThrowingEnumerable();
var result = deferredFunction(source);
using (var iterator = result.GetEnumerator())
{
Assert.Throws <InvalidOperationException>(() => iterator.MoveNext());
}
}
public void Execution_Is_Deferred_With_Index()
{
ThrowingEnumerable.AssertDeferred(src => src.Where((x, index) => x > 0));
}
public void Execution_Is_Deferred()
{
ThrowingEnumerable.AssertDeferred(src => src.Where(x => x > 0));
}