// in a situation where a win can be forced, the AI must always force it
public void PlayerAIAlphaBeta9_WinnableState_AlwaysForcesWin()
{
// Arrange
Player alphabeta1 = new PlayerAIAlphaBeta('X', "AlphaBeta 1", 9);
Player alphabeta2 = new PlayerAIAlphaBeta('O', "AlphaBeta 2", 9);
// Act & Assert
bool?[,] board;
for (int i = 0; i < iterations; i++)
{
board = new bool?[, ] {
{ true, null, null }, { null, null, null }, { null, false, null }
};
Assert.That(TestsMain.SimulateGameFromState(alphabeta1, alphabeta2, true, board), Is.Not.EqualTo(-1));
}
}
// minimax with AlphaBeta with sufficient depth will always draw against itself
public void PlayerAIAlphaBeta9_vsPlayerAIAlphaBeta9_AlwaysATie()
{
// Arrange
Player alphabeta1 = new PlayerAIAlphaBeta('X', "AlphaBeta1", 9);
Player alphabeta2 = new PlayerAIAlphaBeta('O', "AlphaBeta2", 9);
// Act & Assert
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(alphabeta1, alphabeta2), Is.Not.EqualTo(-1).And.Not.EqualTo(1));
}
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(alphabeta2, alphabeta1), Is.Not.EqualTo(-1).And.Not.EqualTo(1));
}
}
// AlphaBeta should be no different from Minimax regarding the quality of decision making,
// only faster, so they should always draw against each other
public void PlayerAIAlphaBeta9_vsPlayerAIMinimax9_AlwaysATie()
{
// Arrange
Player minimax = new PlayerAIMinimax('X', "Minimax", 9);
Player alphabeta = new PlayerAIAlphaBeta('O', "AlphaBeta", 9);
// Act & Assert
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(minimax, alphabeta), Is.Not.EqualTo(-1).And.Not.EqualTo(1));
}
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(alphabeta, minimax), Is.Not.EqualTo(-1).And.Not.EqualTo(1));
}
}
// just like minimax, minimax with alphabeta should never lose to a random AI
public void PlayerAIAlphaBeta9_vsPlayerAIRandom_NeverLoses()
{
// Arrange
Player alphabeta = new PlayerAIAlphaBeta('X', "AlphaBeta", 9);
Player random = new PlayerAIRandom('O', "Random");
// Act & Assert
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(alphabeta, random), Is.Not.EqualTo(-1));
}
for (int i = 0; i < iterations; i++)
{
Assert.That(TestsMain.SimulateGame(random, alphabeta), Is.Not.EqualTo(1));
}
}
