public void Create_WithNonEmptyIEnumerable()
{
string characters = "hello";
CurrentIndexIterator <char> iterator = CurrentIndexIterator.Create(characters);
Assert.IsNotNull(iterator);
Assert.IsFalse(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
int expectedCurrentIndex = 0;
foreach (char character in characters)
{
Assert.IsTrue(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsTrue(iterator.HasCurrent());
Assert.AreEqual(character, iterator.Current);
Assert.AreEqual(expectedCurrentIndex, iterator.GetCurrentIndex());
expectedCurrentIndex++;
}
for (int i = 0; i < 2; ++i)
{
Assert.IsFalse(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
Assert.ThrowsException <PreConditionException>(() => iterator.Current);
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
}
}
public void Create_WithFinishedIEnumerator()
{
string characters = "";
IEnumerator <char> enumerator = characters.GetEnumerator();
Assert.IsFalse(enumerator.MoveNext());
CurrentIndexIterator <char> iterator = CurrentIndexIterator.Create(enumerator);
Assert.IsNotNull(iterator);
Assert.IsTrue(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
Assert.ThrowsException <PreConditionException>(() => iterator.Current);
Assert.ThrowsException <InvalidOperationException>(() => enumerator.Current);
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
for (int i = 0; i < 2; ++i)
{
Assert.IsFalse(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
Assert.ThrowsException <PreConditionException>(() => iterator.Current);
Assert.ThrowsException <InvalidOperationException>(() => enumerator.Current);
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
}
}
public void Create_WithEmptyIEnumerable()
{
CurrentIndexIterator <char> iterator = CurrentIndexIterator.Create("");
Assert.IsFalse(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
for (int i = 0; i < 2; ++i)
{
Assert.IsFalse(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
}
}
public void Create_WithStartedIEnumerator()
{
string characters = "hello";
IEnumerator <char> enumerator = characters.GetEnumerator();
Assert.IsTrue(enumerator.MoveNext());
CurrentIndexIterator <char> iterator = CurrentIndexIterator.Create(enumerator);
Assert.IsNotNull(iterator);
Assert.IsTrue(iterator.HasStarted());
Assert.IsTrue(iterator.HasCurrent());
Assert.AreEqual('h', iterator.Current);
Assert.AreEqual('h', enumerator.Current);
int expectedCurrentIndex = 0;
Assert.AreEqual(expectedCurrentIndex, iterator.GetCurrentIndex());
expectedCurrentIndex++;
foreach (char character in characters.Skip(1))
{
Assert.IsTrue(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsTrue(iterator.HasCurrent());
Assert.AreEqual(character, iterator.Current);
Assert.AreEqual(character, enumerator.Current);
Assert.AreEqual(expectedCurrentIndex, iterator.GetCurrentIndex());
expectedCurrentIndex++;
}
for (int i = 0; i < 2; ++i)
{
Assert.IsFalse(iterator.Next());
Assert.IsTrue(iterator.HasStarted());
Assert.IsFalse(iterator.HasCurrent());
Assert.ThrowsException <PreConditionException>(() => iterator.Current);
Assert.ThrowsException <InvalidOperationException>(() => enumerator.Current);
AssertEx.Throws(() => iterator.GetCurrentIndex(),
new PreConditionException("this.HasCurrent() cannot be false."));
}
}
public void Create_WithNullIEnumerable()
{
Assert.ThrowsException <PreConditionException>(() => CurrentIndexIterator.Create((IEnumerable <char>)null));
}
