[Bug] Fix speed tie code (#1895)

* Fix speed tie code

* Fix off by one error

* Shuffle before sorting to make code cleaner

src/phases.ts

@@ -633,11 +633,12 @@ export abstract class FieldPhase extends BattlePhase {
     const playerField = this.scene.getPlayerField().filter(p => p.isActive()) as Pokemon[];
     const enemyField = this.scene.getEnemyField().filter(p => p.isActive()) as Pokemon[];
 
-    let orderedTargets: Pokemon[] = playerField.concat(enemyField).sort((a: Pokemon, b: Pokemon) => {
+    // We shuffle the list before sorting so speed ties produce random results
+    let orderedTargets: Pokemon[] = Utils.randSeedShuffle(playerField.concat(enemyField)).sort((a: Pokemon, b: Pokemon) => {
       const aSpeed = a?.getBattleStat(Stat.SPD) || 0;
       const bSpeed = b?.getBattleStat(Stat.SPD) || 0;
 
-      return aSpeed < bSpeed ? 1 : aSpeed > bSpeed ? -1 : !this.scene.randBattleSeedInt(2) ? -1 : 1;
+      return bSpeed - aSpeed;
     });
 
     const speedReversed = new Utils.BooleanHolder(false);

src/utils.ts

@@ -127,6 +127,23 @@ export function randSeedEasedWeightedItem<T>(items: T[], easingFunction: string
   return items[Math.floor(easedValue * items.length)];
 }
 
+/**
+ * Shuffle a list using the seeded rng. Utilises the Fisher-Yates algorithm.
+ * @param {Array} items An array of items.
+ * @returns {Array} A new shuffled array of items.
+ */
+export function randSeedShuffle<T>(items: T[]): T[] {
+  if (items.length <= 1) {
+    return items;
+  }
+  const newArray = items.slice(0);
+  for (let i = items.length - 1; i > 0; i--) {
+    const j = Phaser.Math.RND.integerInRange(0, i);
+    [newArray[i], newArray[j]] = [newArray[j], newArray[i]];
+  }
+  return newArray;
+}
+
 export function getFrameMs(frameCount: integer): integer {
   return Math.floor((1 / 60) * 1000 * frameCount);
 }