public void ResetWhenReadAheadLimitExceededAfterMarkAndResetThrowsException()
{
// given
const string input = "abcdefgh";
var target = new DefaultResettableReader(input);
// when
target.Mark(5);
// then
for (var i = 0; i < 5; i++)
{
var chr = target.Read();
Assert.That(chr, Is.EqualTo(input[i]));
}
// and when
target.Reset();
target.Mark(3);
// then
for (var i = 0; i < 4; i++)
{
var chr = target.Read();
Assert.That(chr, Is.EqualTo(input[i]));
}
var ex = Assert.Throws <InvalidOperationException>(() => target.Reset());
Assert.That(ex.Message, Is.EqualTo("Cannot reset beyond 3 positions. Tried to reset 4 positions"));
}
public void MarkWithHigherReadAheadLimitThanPreviousMarkOnOddPosition()
{
// given
const string input = "abcde";
var target = new DefaultResettableReader(input);
// when
target.Mark(1);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
target.Mark(1);
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when reading from reset reader at odd position
target.Reset();
target.Mark(2);
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('c'));
// and when
target.Reset();
// then
for (var i = 1; i < input.Length; i++)
{
obtained = target.Read();
Assert.That(obtained, Is.EqualTo(input[i]));
}
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(-1));
}
public void MarkWithLowerReadAheadLimitThanPreviousMark()
{
// given
const string input = "abcd";
var target = new DefaultResettableReader(input);
// when
target.Mark(2);
// then
for (var i = 0; i < 2; i++)
{
var chr = target.Read();
Assert.That(chr, Is.EqualTo(input[i]));
}
// and when
target.Reset();
for (var i = 0; i < 3; i++)
{
// and when
target.Mark(1);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(input[i]));
// and when
target.Reset();
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(input[i]));
}
// and when reading to end, then
for (var i = 3; i < input.Length; i++)
{
var obtained = target.Read();
Assert.That(obtained, Is.EqualTo(input[i]));
}
// and finally when
var lastReadChr = target.Read();
// then
Assert.That(lastReadChr, Is.EqualTo(-1));
}
public void MarkWithNegativeLookAheadLimitThrowsException()
{
// given
var target = new DefaultResettableReader("abcd");
// when, then
var ex = Assert.Throws <ArgumentException>(() => target.Mark(-1));
Assert.That(ex.Message, Is.EqualTo("readAheadLimit < 0"));
}
public void MarkWithHigherReadAheadLimitThanPreviousMarkOnEvenPosition()
{
// given
const string input = "abcde";
var target = new DefaultResettableReader(input);
// when
target.Mark(1);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when reading from reset reader at even position
target.Reset();
target.Mark(2);
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when
target.Reset();
// then
foreach (var c in input)
{
obtained = target.Read();
Assert.That(obtained, Is.EqualTo(c));
}
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(-1));
}
public void MarkAndReadAfterNotReadingAllPreviouslyMarkedCharacters()
{
// given
const string input = "abcdef";
var target = new DefaultResettableReader(input);
// when
target.Mark(2);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
target.Mark(3);
// then
for (var i = 1; i < 4; i++)
{
obtained = target.Read();
Assert.That(obtained, Is.EqualTo(input[i]));
}
// and when
target.Reset();
// then
for (var i = 1; i < input.Length; i++)
{
obtained = target.Read();
Assert.That(obtained, Is.EqualTo(input[i]));
}
obtained = target.Read();
Assert.That(obtained, Is.EqualTo(-1));
}
public void ResetAfterReadAheadLimitExceededThrowsException()
{
// given
var target = new DefaultResettableReader("abcd");
// when
target.Mark(1);
target.Read();
target.Read();
// then
var ex = Assert.Throws <InvalidOperationException>(() => target.Reset());
Assert.That(ex.Message, Is.EqualTo("Cannot reset beyond 1 positions. Tried to reset 2 positions"));
}
public void ReadAfterMarkAndResettingTwoCharactersWithOddReadOffset()
{
// given
const string input = "abcd";
var target = new DefaultResettableReader(input);
// when
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
target.Mark(2);
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('c'));
// and when
target.Reset();
for (var i = 1; i < input.Length; i++)
{
// when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(input[i]));
}
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(-1));
}
public void ReadAfterMarkAndResettingTwoCharactersWithEvenReadOffset()
{
// given
const string input = "abc";
var target = new DefaultResettableReader(input);
// when
target.Mark(2);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when
target.Reset();
foreach (var chr in input)
{
// when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(chr));
}
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(-1));
}
public void ReadAfterMarkAndResettingSingleCharacter()
{
// given
var target = new DefaultResettableReader("abc");
// when
target.Mark(1);
var obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
target.Reset();
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('a'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('b'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo('c'));
// and when
obtained = target.Read();
// then
Assert.That(obtained, Is.EqualTo(-1));
}