public void FirstSequenceIsNotUsedUntilQueryIsIterated()
{
var first = new ThrowingEnumerable();
int[] second = { 2 };
var query = first.Union(second);
using (var iterator = query.GetEnumerator())
{
Assert.Throws <InvalidOperationException>(() => iterator.MoveNext());
}
}
public void NoSequencesUsedBeforeIteration()
{
var first = new ThrowingEnumerable();
var second = new ThrowingEnumerable();
// No exceptions!
var query = first.Union(second);
// Still no exceptions... we're not calling MoveNext.
using (var iterator = query.GetEnumerator())
{
}
}