Feat/hand

src/Domain/Hand.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace App\Domain;
+
+final class Hand
+{
+    public function __construct(
+        private array $cards = []
+    ) {}
+
+    public function addCard(Card $card): void
+    {
+        $this->cards[] = $card;
+    }
+
+    public function value(): int
+    {
+        $total = 0;
+        $aces = 0;
+
+        foreach ($this->cards as $card) {
+            $total += $card->numericValue();
+            if ($card->rank() === 'Ace') {
+                $aces++;
+            }
+        }
+
+        while ($total > 21 && $aces > 0) {
+            $total -= 10;
+            $aces--;
+        }
+
+        return $total;
+    }
+
+    public function isBlackjack(): bool
+    {
+        return count($this->cards) === 2 && $this->value() === 21;
+    }
+
+    public function isBust(): bool
+    {
+        return $this->value() > 21;
+    }
+
+    public function isSoft(): bool
+    {
+        $total = 0;
+        $aces = 0;
+
+        foreach ($this->cards as $card) {
+            $total += $card->numericValue();
+            if ($card->rank() === 'Ace') {
+                $aces++;
+            }
+        }
+
+        return $aces > 0 && $total <= 21;
+    }
+}

tests/Domain/HandTest.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace App\Tests\Domain;
+
+use App\Domain\Card;
+use App\Domain\Hand;
+use PHPUnit\Framework\TestCase;
+
+final class HandTest extends TestCase
+{
+    public function testEmptyHandHasValueOfZero(): void
+    {
+        $hand = new Hand();
+
+        $this->assertSame(0, $hand->value());
+    }
+
+    public function testHandWithOneCardReturnsCardValue(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('7', 'Hearts'));
+
+        $this->assertSame(7, $hand->value());
+    }
+
+    public function testAceCountsAsOneWhenHandWouldBust(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('Ace', 'Hearts'));
+        $hand->addCard(new Card('King', 'Spades'));
+        $hand->addCard(new Card('5', 'Diamonds'));
+
+        $this->assertSame(16, $hand->value());
+    }
+
+    public function testNaturalBlackjackWithAceAndKing(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('Ace', 'Hearts'));
+        $hand->addCard(new Card('King', 'Spades'));
+
+        $this->assertTrue($hand->isBlackjack());
+    }
+
+    public function testThreeCardTwentyOneIsNotBlackjack(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('7', 'Hearts'));
+        $hand->addCard(new Card('7', 'Spades'));
+        $hand->addCard(new Card('7', 'Diamonds'));
+
+        $this->assertFalse($hand->isBlackjack());
+    }
+
+    public function testHandIsBustWhenValueExceeds21(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('King', 'Hearts'));
+        $hand->addCard(new Card('Queen', 'Spades'));
+        $hand->addCard(new Card('5', 'Diamonds'));
+
+        $this->assertTrue($hand->isBust());
+    }
+
+    public function testHandWithAceCountedAs11IsSoft(): void
+    {
+        $hand = new Hand();
+        $hand->addCard(new Card('Ace', 'Hearts'));
+        $hand->addCard(new Card('6', 'Spades'));
+
+        $this->assertTrue($hand->isSoft());
+    }
+}