poker_test.py

import unittest

from poker import best_hands

# Tests adapted from `problem-specifications//canonical-data.json`


class PokerTest(unittest.TestCase):
    def test_single_hand_always_wins(self):
        self.assertEqual(best_hands(["4S 5S 7H 8D JC"]), ["4S 5S 7H 8D JC"])

    def test_highest_card_out_of_all_hands_wins(self):
        self.assertEqual(
            best_hands(["4D 5S 6S 8D 3C", "2S 4C 7S 9H 10H", "3S 4S 5D 6H JH"]),
            ["3S 4S 5D 6H JH"],
        )

    def test_a_tie_has_multiple_winners(self):
        self.assertEqual(
            best_hands(
                [
                    "4D 5S 6S 8D 3C",
                    "2S 4C 7S 9H 10H",
                    "3S 4S 5D 6H JH",
                    "3H 4H 5C 6C JD",
                ]
            ),
            ["3S 4S 5D 6H JH", "3H 4H 5C 6C JD"],
        )

    def test_multiple_hands_with_the_same_high_cards_tie_compares_next_highest_ranked_down_to_last_card(
        self
    ):
        self.assertEqual(
            best_hands(["3S 5H 6S 8D 7H", "2S 5D 6D 8C 7S"]), ["3S 5H 6S 8D 7H"]
        )

    def test_one_pair_beats_high_card(self):
        self.assertEqual(
            best_hands(["4S 5H 6C 8D KH", "2S 4H 6S 4D JH"]), ["2S 4H 6S 4D JH"]
        )

    def test_highest_pair_wins(self):
        self.assertEqual(
            best_hands(["4S 2H 6S 2D JH", "2S 4H 6C 4D JD"]), ["2S 4H 6C 4D JD"]
        )

    def test_two_pairs_beats_one_pair(self):
        self.assertEqual(
            best_hands(["2S 8H 6S 8D JH", "4S 5H 4C 8C 5C"]), ["4S 5H 4C 8C 5C"]
        )

    def test_both_hands_have_two_pairs_highest_ranked_pair_wins(self):
        self.assertEqual(
            best_hands(["2S 8H 2D 8D 3H", "4S 5H 4C 8S 5D"]), ["2S 8H 2D 8D 3H"]
        )

    def test_both_hands_have_two_pairs_with_the_same_highest_ranked_pair_tie_goes_to_low_pair(
        self
    ):
        self.assertEqual(
            best_hands(["2S QS 2C QD JH", "JD QH JS 8D QC"]), ["JD QH JS 8D QC"]
        )

    def test_both_hands_have_two_identically_ranked_pairs_tie_goes_to_remaining_card_kicker(
        self
    ):
        self.assertEqual(
            best_hands(["JD QH JS 8D QC", "JS QS JC 2D QD"]), ["JD QH JS 8D QC"]
        )

    def test_three_of_a_kind_beats_two_pair(self):
        self.assertEqual(
            best_hands(["2S 8H 2H 8D JH", "4S 5H 4C 8S 4H"]), ["4S 5H 4C 8S 4H"]
        )

    def test_both_hands_have_three_of_a_kind_tie_goes_to_highest_ranked_triplet(self):
        self.assertEqual(
            best_hands(["2S 2H 2C 8D JH", "4S AH AS 8C AD"]), ["4S AH AS 8C AD"]
        )

    def test_with_multiple_decks_two_players_can_have_same_three_of_a_kind_ties_go_to_highest_remaining_cards(
        self
    ):
        self.assertEqual(
            best_hands(["4S AH AS 7C AD", "4S AH AS 8C AD"]), ["4S AH AS 8C AD"]
        )

    def test_a_straight_beats_three_of_a_kind(self):
        self.assertEqual(
            best_hands(["4S 5H 4C 8D 4H", "3S 4D 2S 6D 5C"]), ["3S 4D 2S 6D 5C"]
        )

    def test_aces_can_end_a_straight_10_j_q_k_a(self):
        self.assertEqual(
            best_hands(["4S 5H 4C 8D 4H", "10D JH QS KD AC"]), ["10D JH QS KD AC"]
        )

    def test_aces_can_start_a_straight_a_2_3_4_5(self):
        self.assertEqual(
            best_hands(["4S 5H 4C 8D 4H", "4D AH 3S 2D 5C"]), ["4D AH 3S 2D 5C"]
        )

    def test_both_hands_with_a_straight_tie_goes_to_highest_ranked_card(self):
        self.assertEqual(
            best_hands(["4S 6C 7S 8D 5H", "5S 7H 8S 9D 6H"]), ["5S 7H 8S 9D 6H"]
        )

    def test_even_though_an_ace_is_usually_high_a_5_high_straight_is_the_lowest_scoring_straight(
        self
    ):
        self.assertEqual(
            best_hands(["2H 3C 4D 5D 6H", "4S AH 3S 2D 5H"]), ["2H 3C 4D 5D 6H"]
        )

    def test_flush_beats_a_straight(self):
        self.assertEqual(
            best_hands(["4C 6H 7D 8D 5H", "2S 4S 5S 6S 7S"]), ["2S 4S 5S 6S 7S"]
        )

    def test_both_hands_have_a_flush_tie_goes_to_high_card_down_to_the_last_one_if_necessary(
        self
    ):
        self.assertEqual(
            best_hands(["4H 7H 8H 9H 6H", "2S 4S 5S 6S 7S"]), ["4H 7H 8H 9H 6H"]
        )

    def test_full_house_beats_a_flush(self):
        self.assertEqual(
            best_hands(["3H 6H 7H 8H 5H", "4S 5H 4C 5D 4H"]), ["4S 5H 4C 5D 4H"]
        )

    def test_both_hands_have_a_full_house_tie_goes_to_highest_ranked_triplet(self):
        self.assertEqual(
            best_hands(["4H 4S 4D 9S 9D", "5H 5S 5D 8S 8D"]), ["5H 5S 5D 8S 8D"]
        )

    def test_with_multiple_decks_both_hands_have_a_full_house_with_the_same_triplet_tie_goes_to_the_pair(
        self
    ):
        self.assertEqual(
            best_hands(["5H 5S 5D 9S 9D", "5H 5S 5D 8S 8D"]), ["5H 5S 5D 9S 9D"]
        )

    def test_four_of_a_kind_beats_a_full_house(self):
        self.assertEqual(
            best_hands(["4S 5H 4D 5D 4H", "3S 3H 2S 3D 3C"]), ["3S 3H 2S 3D 3C"]
        )

    def test_both_hands_have_four_of_a_kind_tie_goes_to_high_quad(self):
        self.assertEqual(
            best_hands(["2S 2H 2C 8D 2D", "4S 5H 5S 5D 5C"]), ["4S 5H 5S 5D 5C"]
        )

    def test_with_multiple_decks_both_hands_with_identical_four_of_a_kind_tie_determined_by_kicker(
        self
    ):
        self.assertEqual(
            best_hands(["3S 3H 2S 3D 3C", "3S 3H 4S 3D 3C"]), ["3S 3H 4S 3D 3C"]
        )

    def test_straight_flush_beats_four_of_a_kind(self):
        self.assertEqual(
            best_hands(["4S 5H 5S 5D 5C", "7S 8S 9S 6S 10S"]), ["7S 8S 9S 6S 10S"]
        )

    def test_both_hands_have_straight_flush_tie_goes_to_highest_ranked_card(self):
        self.assertEqual(
            best_hands(["4H 6H 7H 8H 5H", "5S 7S 8S 9S 6S"]), ["5S 7S 8S 9S 6S"]
        )


if __name__ == "__main__":
    unittest.main()