public void MovingTapeLeftBringsBlankCellIntoView()
{
Tape tape = new Tape();
tape.Write('a');
tape.MoveLeft();
Assert.AreEqual(' ', tape.Read());
}
public void GetIndexReturnsCurrentTapeIndex()
{
Tape tape = new Tape();
tape.MoveRight();
Assert.AreEqual(1, tape.GetIndex());
tape.MoveLeft();
Assert.AreEqual(0, tape.GetIndex());
}
public void MovingTapeLeftThenRightReturnsTapeToOriginalPosition()
{
Tape tape = new Tape();
char symbol = 'a';
tape.Write(symbol);
tape.MoveLeft();
tape.MoveRight();
Assert.AreEqual(symbol, tape.Read());
}
public void TapeStoresAllWrittenSymbolsAsItMovesRight()
{
Tape tape = new Tape();
List<char> symbols = new List<char>() { 'a', 'b', 'c', 'd' };
for(int symbolIndex = 0; symbolIndex < symbols.Count; ++symbolIndex)
{
tape.Write(symbols[symbolIndex]);
tape.MoveRight();
}
for (int symbolIndex = symbols.Count - 1; symbolIndex >= 0; --symbolIndex)
{
tape.MoveLeft();
Assert.AreEqual(symbols[symbolIndex], tape.Read());
}
}
