Adds the possibility to serialize a battle state for saving it

src/Battle.php

@@ -61,13 +61,46 @@ class Battle
      * @param FighterInterface $player
      * @param FighterInterface $monster
      */
-    public function __construct(Game $game, FighterInterface $player, FighterInterface $monster)
+    public function __construct(Game $game, FighterInterface $player, ?FighterInterface $monster)
     {
         $this->game = $game;
         $this->player = $player;
         $this->monster = $monster;
         $this->events = new ArrayCollection();
     }
+
+    /**
+     * Returns a string which contains the important fields that must be serialized.
+     * @return string
+     */
+    public function serialize(): string
+    {
+        return serialize([
+            "monster" => $this->monster,
+            "result" => $this->result,
+            "round" => $this->round,
+            "configuration" => $this->configuration,
+        ]);
+    }
+
+    /**
+     * @param Game $game
+     * @param FighterInterface $player
+     * @param string $serialized
+     * @return Battle
+     */
+    public static function unserialize(Game $game, FighterInterface $player, string $serialized): self
+    {
+        $battle = new self($game, $player, null);
+        $unserialized = unserialize($serialized);
+
+        $battle->monster  = $unserialized["monster"];
+        $battle->result = $unserialized["result"];
+        $battle->round = $unserialized["round"];
+        $battle->configuration = $unserialized["configuration"];
+
+        return $battle;
+    }
     
     /**
      * @ToDo Returns at some point battle actions

tests/BattleTest.php

@@ -91,6 +91,35 @@ class BattleTest extends CoreModelTestCase
         $this->assertTrue($character->isAlive() xor $monster->isAlive());
     }
 
+    /**
+     * Tests if a fight can happen if it is serialized between each round.
+     */
+    public function testFairBattleWithSerializationBetweenRounds()
+    {
+        $em = $this->getEntityManager();
+
+        $character = $em->getRepository(Character::class)->find(1);
+        $monster = $em->getRepository(Monster::class)->find(1);
+
+        $battle = new Battle($this->getMockGame($character), $character, $monster);
+        $battle = $battle->serialize();
+
+        for ($n = 0; $n < 99; $n++) {
+            $battle = Battle::unserialize($this->getMockGame($character), $character, $battle);
+
+            $battle->fightNRounds(1);
+
+            if ($battle->isOver()) {
+                break;
+            }
+
+            $battle = $battle->serialize();
+        }
+
+        $this->assertTrue($battle->isOver());
+        $this->assertTrue($battle->getPlayer()->isAlive() xor $battle->getMonster()->isAlive());
+    }
+
     /**
      * Tests a fight which the player has to win (lvl 100 vs lvl 1)
      */

tests/DiceBagTest.php

@@ -58,7 +58,7 @@ class DiceBagTests extends \PHPUnit_Framework_TestCase
         $value = $db->dice(1, 6);
         $this->assertGreaterThanOrEqual(1, $value);
         $this->assertLessThanOrEqual(6, $value);
-        
+
         $value = $db->dice(5, 5);
         $this->assertSame(5, $value);