Write tests for hand_type and correct exposed bugs

src/hand.rs

@@ -2,7 +2,7 @@ use crate::card::{CardValue, PlayingCard};
 use core::fmt;
 use std::collections::HashMap;
 
-#[derive(Clone, Copy, PartialEq, Eq, Ord, PartialOrd)]
+#[derive(Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Debug)]
 pub enum HandType {
     HighCard,
     OnePair,
@@ -214,8 +214,8 @@ fn is_straight_flush(hand: &PokerHand) -> bool {
     assert!(hand.len() == 5);
 
     let suit = hand[0].suit;
-    let mut min_val = CardValue::Two;
-    let mut max_val = CardValue::Ace;
+    let mut min_val = CardValue::Ace;
+    let mut max_val = CardValue::Two;
 
     // Must all be the same suit
     for i in 0..5 {
@@ -294,7 +294,7 @@ fn is_flush(hand: &PokerHand) -> bool {
 fn is_straight(hand: &PokerHand) -> bool {
     for i in 1..4 {
         let current_card = hand.cards[i].value as u8;
-        let previous_card = hand.cards[i].value as u8;
+        let previous_card = hand.cards[i - 1].value as u8;
         if current_card != previous_card - 1 {
             return false;
         }
@@ -325,3 +325,259 @@ fn is_one_pair(hand: &PokerHand) -> bool {
     // https://stackoverflow.com/questions/45353757/how-to-count-the-elements-in-a-vector-with-some-value-without-looping
     count.iter().filter(|&n| *n == 2).count() == 1
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::card::CardSuit;
+
+    use super::*;
+
+    #[test]
+    fn one_pair_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Ace,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Ace,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Two,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Eight,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::OnePair);
+
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Ace,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::King,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Two,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Eight,
+        };
+
+        let nopair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(nopair);
+        assert_eq!(hand.hand_type(), HandType::HighCard);
+    }
+
+    #[test]
+    fn two_pair_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Ace,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Ace,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Two,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::TwoPair);
+    }
+
+    #[test]
+    fn three_of_a_kind_tests() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Ace,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Ace,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Spades,
+            value: CardValue::Ace,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Two,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::ThreeOfAKind);
+    }
+
+    #[test]
+    fn staight_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Eight,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Spades,
+            value: CardValue::Seven,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Five,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Nine,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::Straight);
+    }
+
+    #[test]
+    fn flush_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Two,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Queen,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Jack,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Ace,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::Flush);
+    }
+
+    #[test]
+    fn full_house_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Six,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Spades,
+            value: CardValue::Two,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Two,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::FullHouse);
+    }
+
+    #[test]
+    fn four_of_a_kind_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Six,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Spades,
+            value: CardValue::Six,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Six,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Clubs,
+            value: CardValue::Two,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::FourOfAKind);
+    }
+
+    #[test]
+    fn straight_flush_test() {
+        let card1 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Jack,
+        };
+        let card2 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Ten,
+        };
+        let card3 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Nine,
+        };
+        let card4 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Seven,
+        };
+        let card5 = PlayingCard {
+            suit: CardSuit::Diamonds,
+            value: CardValue::Eight,
+        };
+
+        let pair = vec![card1, card2, card3, card4, card5];
+        let hand = PokerHand::new(pair);
+        assert_eq!(hand.hand_type(), HandType::StraightFlush);
+    }
+}