Initial battle class tests.

PkmnLibSharp/Battling/Battle/Battle.cs

@@ -8,13 +8,14 @@ namespace PkmnLibSharp.Battling
 {
     public class Battle : PointerWrapper
     {
-        public Battle(BattleLibrary library, BattleParty[] parties, bool canFlee, byte numberOfSides, byte creaturesPerSide,
+        public Battle(BattleLibrary library, BattleParty[] parties, bool canFlee, byte numberOfSides, byte pokemonPerSide,
             ulong randomSeed)
         {
             var ptr = IntPtr.Zero;
             var arr = parties.Select(x => x.Ptr).ToArray();
             Pkmnlib.Generated.Battle.Construct(ref ptr, library.Ptr, arr.ArrayPtr(), (ulong) arr.Length,
-                canFlee.ToNative(), numberOfSides, creaturesPerSide, randomSeed);
+                canFlee.ToNative(), numberOfSides, pokemonPerSide, randomSeed);
+            Initialize(ptr);
         }
 
         public BattleLibrary Library

PkmnLibSharp/Battling/Battle/BattleBuilder.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace PkmnLibSharp.Battling
+{
+    public class BattleBuilder
+    {
+        private readonly BattleLibrary _library;
+        private readonly bool _canFlee;
+        private readonly byte _numberOfSides;
+        private readonly byte _pokemonPerSide;
+        private ulong? _seed;
+        private readonly List<BattleParty> _parties = new List<BattleParty>();
+        
+        public BattleBuilder(BattleLibrary library, bool canFlee, byte numberOfSides = 2, byte pokemonPerSide = 1)
+        {
+            _library = library;
+            _canFlee = canFlee;
+            _numberOfSides = numberOfSides;
+            _pokemonPerSide = pokemonPerSide;
+        }
+
+        public BattleBuilder WithRandomSeed(ulong seed)
+        {
+            _seed = seed;
+            return this;
+        }
+
+        public BattleBuilder WithPartyOnPositions(PokemonParty party, params BattlePosition[] positions)
+        {
+            var battleParty = new BattleParty(party, positions.SelectMany(x => new[] {x.Side, x.Index}).ToArray());
+            _parties.Add(battleParty);
+            return this;
+        }
+
+        public Battle Build()
+        {
+            // Use the milliseconds since epoch time as random seed if none is specified.
+            _seed ??= (ulong) (DateTime.UtcNow - new DateTime(1970, 1, 1)).TotalMilliseconds;
+            return new Battle(_library, _parties.ToArray(), _canFlee, _numberOfSides, _pokemonPerSide, _seed.Value);
+        }
+    }
+}

PkmnLibSharp/Battling/Battle/BattleParty.cs

@@ -11,7 +11,7 @@ namespace PkmnLibSharp.Battling
         {
             var ptr = IntPtr.Zero;
             Creaturelibbattling.Generated.BattleParty.Construct(ref ptr, party.Ptr, responsibleIndices.ArrayPtr(),
-                (ulong) responsibleIndices.Length).Assert();
+                (ulong) responsibleIndices.Length / 2).Assert();
             Initialize(ptr);
         }
 

PkmnLibSharp/Battling/Battle/BattlePosition.cs

@@ -0,0 +1,14 @@
+namespace PkmnLibSharp.Battling
+{
+    public readonly struct BattlePosition
+    {
+        public readonly byte Side;
+        public readonly byte Index;
+
+        public BattlePosition(byte side, byte index)
+        {
+            Side = side;
+            Index = index;
+        }
+    }
+}

PkmnLibSharp/Battling/Pokemon.cs

@@ -319,11 +319,11 @@ namespace PkmnLibSharp.Battling
 
         protected internal override void MarkAsDeleted()
         {
-            base.MarkAsDeleted();
             foreach (var move in Moves)
             {
-                move.MarkAsDeleted();
+                move?.MarkAsDeleted();
             }
+            base.MarkAsDeleted();
         }
     }
 }

PkmnLibSharp/Battling/PokemonParty.cs

@@ -7,7 +7,7 @@ namespace PkmnLibSharp.Battling
     {
         private ReadOnlyNativePtrArray<Pokemon> _party;
         
-        public PokemonParty(ulong size) : base(Creaturelibbattling.Generated.CreatureParty.ConstructWithSize(size))
+        public PokemonParty(ulong size = 6) : base(Creaturelibbattling.Generated.CreatureParty.ConstructWithSize(size))
         {}
 
         public PokemonParty(Pokemon[] pokemon) : base(