public void AsOneTime()
{
var source = new[] { 1, 2, 3 };
OneTimeEnumerable <int> result = source.AsOneTime();
Assert.That(result, Is.EqualTo(source));
}
public void GetEnumerator_ThrowsForSecondCall()
{
var source = Enumerable.Range(1, 3);
var oneTime = new OneTimeEnumerable <int> (source);
Assert.That(() => oneTime.GetEnumerator(), Throws.Nothing);
Assert.That(
() => oneTime.GetEnumerator(),
Throws.TypeOf <InvalidOperationException> ().With.Message.EqualTo("OneTimeEnumerable can only be iterated once."));
}
public void When_collection_is_IEnumerable_it_should_be_evaluated_only_once()
{
// Arrange
IEnumerable <int> collection = new OneTimeEnumerable <int>(1);
// Act
Action act = () => collection.Should().ContainSingle();
// Assert
act.Should().NotThrow();
}
public void GetEnumerator_ReturnedEnumeratorDoesNotSupportReset()
{
var source = new[] { 1, 2, 3 };
var oneTimeEnumerator = new OneTimeEnumerable <int> (source).GetEnumerator();
oneTimeEnumerator.MoveNext();
Assert.That(
() => oneTimeEnumerator.Reset(),
Throws.TypeOf <NotSupportedException>().With.Message.EqualTo("OneTimeEnumerator does not support Reset()."));
}
public void When_a_collection_does_not_contain_the_unexpected_items_it_should_not_be_enumerated_twice()
{
// Arrange
var collection = new OneTimeEnumerable <int>(1, 2, 3);
// Act
Action act = () => collection.Should().OnlyContain(i => i > 3);
// Assert
act.Should().Throw <XunitException>().WithMessage(
"Expected collection to contain only items matching*");
}
public void When_a_collection_contains_the_unexpected_item_it_should_not_be_enumerated_twice()
{
// Arrange
var collection = new OneTimeEnumerable <int>(1, 2, 3);
// Act
Action act = () => collection.Should().NotContain(2);
// Assert
act.Should().Throw <XunitException>().WithMessage(
"Expected collection*to not contain 2.");
}
