public void Enumerate_SingleEntry_JustOneEntry()
{
var subject = new SmartEnumerable <string>(new[] { "x" });
Assert.That(subject, Must.Be.Constrained(
Must.Be.Entry(0, "x", isFirst: true, isLast: true)));
}
/// <summary>
/// Returns the penultimate element in the sequence or <c>default(T)</c>
/// </summary>
public static T PenultimateOrDefault <T>(this IEnumerable <T> source)
{
var enumerable = new SmartEnumerable <T>(source);
var lastItem = enumerable.LastOrDefault();
return(lastItem != null ? lastItem.Previous : default(T));
}
public void TripleEntryEnumerable()
{
List <string> list = new List <string>();
list.Add("x");
list.Add("y");
list.Add("z");
SmartEnumerable <string> subject = new SmartEnumerable <string>(list);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = subject.GetEnumerator())
{
Assert.IsTrue(iterator.MoveNext());
Assert.IsTrue(iterator.Current.IsFirst);
Assert.IsFalse(iterator.Current.IsLast);
Assert.AreEqual("x", iterator.Current.Value);
Assert.AreEqual(0, iterator.Current.Index);
Assert.IsTrue(iterator.MoveNext());
Assert.IsFalse(iterator.Current.IsFirst);
Assert.IsFalse(iterator.Current.IsLast);
Assert.AreEqual("y", iterator.Current.Value);
Assert.AreEqual(1, iterator.Current.Index);
Assert.IsTrue(iterator.MoveNext());
Assert.IsFalse(iterator.Current.IsFirst);
Assert.IsTrue(iterator.Current.IsLast);
Assert.AreEqual("z", iterator.Current.Value);
Assert.AreEqual(2, iterator.Current.Index);
Assert.IsFalse(iterator.MoveNext());
}
}
public void SingleEntryEnumerableViaCreate()
{
List <string> list = new List <string>();
list.Add("x");
TestSingleEntry(SmartEnumerable.Create(list));
}
public void SmartEnumerableInitialisesWithEmptyCollection()
{
IList <string> inner = new List <string>();
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
Assert.IsNotNull(smart);
}
public void Enumerate_DoubleEntry_TwoEntries()
{
var subject = new SmartEnumerable <string>(new[] { "x", "y" });
Assert.That(subject, Must.Be.Constrained(
Must.Be.Entry(0, "x", isFirst: true, isLast: false),
Must.Be.Entry(1, "y", isFirst: false, isLast: true)));
}
public void Enumerate_TripleEntry_ThreeEntries()
{
IEnumerable <SmartEntry <string> > subject = new SmartEnumerable <string>(new[] { "x", "y", "z" });
Assert.That(subject, Must.Be.Constrained(
Must.Be.Entry(0, "x", isFirst: true, isLast: false),
Must.Be.Entry(1, "y", isFirst: false, isLast: false),
Must.Be.Entry(2, "z", isFirst: false, isLast: true)));
}
public void EmptyEnumerable()
{
List<string> emptyList = new List<string>();
SmartEnumerable<string> subject = new SmartEnumerable<string>(emptyList);
using (IEnumerator<SmartEnumerable<string>.Entry> iterator = subject.GetEnumerator())
{
Assert.IsFalse(iterator.MoveNext());
}
}
public void SmartEnumerableInitialises()
{
IList <string> inner = new List <string> {
"a", "b", "c"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
Assert.IsNotNull(smart);
}
public void SmartEnumerableDoesNotIterateForEmptyCollection()
{
IList <string> inner = new List <string>();
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
Assert.IsFalse(iterator.MoveNext());
}
}
public void EmptyEnumerable()
{
List <string> emptyList = new List <string>();
SmartEnumerable <string> subject = new SmartEnumerable <string>(emptyList);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = subject.GetEnumerator())
{
Assert.IsFalse(iterator.MoveNext());
}
}
private static void TestSingleEntry(SmartEnumerable <string> subject)
{
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = subject.GetEnumerator())
{
Assert.IsTrue(iterator.MoveNext());
Assert.IsTrue(iterator.Current.IsFirst);
Assert.IsTrue(iterator.Current.IsLast);
Assert.AreEqual("x", iterator.Current.Value);
Assert.AreEqual(0, iterator.Current.Index);
Assert.IsFalse(iterator.MoveNext());
}
}
private static void TestSingleEntry(SmartEnumerable<string> subject)
{
using (IEnumerator<SmartEnumerable<string>.Entry> iterator = subject.GetEnumerator())
{
Assert.IsTrue(iterator.MoveNext());
Assert.IsTrue(iterator.Current.IsFirst);
Assert.IsTrue(iterator.Current.IsLast);
Assert.AreEqual("x", iterator.Current.Value);
Assert.AreEqual(0, iterator.Current.Index);
Assert.IsFalse(iterator.MoveNext());
}
}
public void SmartEnumerableIteratesForCollectionWithSingleEntry()
{
List <string> inner = new List <string> {
"a"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
var current = iterator.Current;
Assert.IsNotNull(current);
}
}
public void SmartEnumerableForCollectionWithMoreThanOneEntryStopsIterating()
{
List <string> inner = new List <string> {
"a", "b"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
iterator.MoveNext();
Assert.IsFalse(iterator.MoveNext());
}
}
public void SingleEntryUntypedEnumerable()
{
List<string> list = new List<string>();
list.Add("x");
IEnumerable subject = new SmartEnumerable<string>(list);
int index = 0;
foreach (SmartEnumerable<string>.Entry item in subject)
{ // only expecting 1
Assert.AreEqual(0, index++);
Assert.AreEqual("x", item.Value);
Assert.IsTrue(item.IsFirst);
Assert.IsTrue(item.IsLast);
Assert.AreEqual(0, item.Index);
}
Assert.AreEqual(1, index);
}
public void SmartEnumerableIteratorWithMoreThanOneEntryReturnsFirstEntryWithExpectedIndex()
{
List <string> inner = new List <string> {
"a", "b"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
var first = iterator.Current;
Assert.AreEqual(0, first.Index);
}
}
public void SmartEnumerableIteratorForCollectionWithMoreThanOneEntryReturnsEntryThatIsFirstButNotLast()
{
List <string> inner = new List <string> {
"a", "b"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
var first = iterator.Current;
Assert.IsTrue(first.IsFirst);
Assert.IsFalse(first.IsLast);
}
}
public void SmartEnumerableIteratorReturnsSingleEntryThatIsFirstAndLastEntry()
{
List <string> inner = new List <string> {
"a"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
var current = iterator.Current;
Assert.IsTrue(current.IsFirst);
Assert.IsTrue(current.IsLast);
}
}
public void SmartEnumerableIteratorReturnsSingleEntryWithExpectedValue()
{
const string expected = "a";
List <string> inner = new List <string> {
"a"
};
SmartEnumerable <string> smart = new SmartEnumerable <string>(inner);
using (IEnumerator <SmartEnumerable <string> .Entry> iterator = smart.GetEnumerator())
{
iterator.MoveNext();
var current = iterator.Current;
Assert.AreEqual(expected, current.Value);
}
}
public void SingleEntryUntypedEnumerable()
{
List <string> list = new List <string>();
list.Add("x");
IEnumerable subject = new SmartEnumerable <string>(list);
int index = 0;
foreach (SmartEnumerable <string> .Entry item in subject)
{ // only expecting 1
Assert.AreEqual(0, index++);
Assert.AreEqual("x", item.Value);
Assert.IsTrue(item.IsFirst);
Assert.IsTrue(item.IsLast);
Assert.AreEqual(0, item.Index);
}
Assert.AreEqual(1, index);
}
public void DoubleEntryEnumerable()
{
List<string> list = new List<string>();
list.Add("x");
list.Add("y");
SmartEnumerable<string> subject = new SmartEnumerable<string>(list);
using (IEnumerator<SmartEnumerable<string>.Entry> iterator = subject.GetEnumerator())
{
Assert.IsTrue(iterator.MoveNext());
Assert.IsTrue(iterator.Current.IsFirst);
Assert.IsFalse(iterator.Current.IsLast);
Assert.AreEqual("x", iterator.Current.Value);
Assert.AreEqual(0, iterator.Current.Index);
Assert.IsTrue(iterator.MoveNext());
Assert.IsFalse(iterator.Current.IsFirst);
Assert.IsTrue(iterator.Current.IsLast);
Assert.AreEqual("y", iterator.Current.Value);
Assert.AreEqual(1, iterator.Current.Index);
Assert.IsFalse(iterator.MoveNext());
}
}
public void Enumerate_EmptyEnumerable_Empty()
{
var subject = new SmartEnumerable <string>(Enumerable.Empty <string>());
Assert.That(subject, Is.Empty);
}