Add isPartner method to trainer class

src/data/moves/move.ts

@@ -6297,7 +6297,7 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
       // Find indices of off-field Pokemon that are eligible to be switched into
       const eligibleNewIndices: number[] = [];
       globalScene.getEnemyParty().forEach((pokemon, index) => {
-        if (pokemon.isAllowedInBattle() && !pokemon.isOnField()) {
+        if (pokemon.isAllowedInBattle() && !pokemon.isOnField() && (pokemon as EnemyPokemon).trainerSlot === (switchOutTarget as EnemyPokemon).trainerSlot) {
           eligibleNewIndices.push(index);
         }
       });

src/field/trainer.ts

@@ -223,6 +223,13 @@ export default class Trainer extends Phaser.GameObjects.Container {
     return this.config.doubleOnly || this.variant === TrainerVariant.DOUBLE;
   }
 
+  /**
+   * Return whether the trainer is a duo, like Tate & Liza
+   */
+  isPartner(): boolean {
+    return this.variant === TrainerVariant.DOUBLE;
+  }
+
   getMixedBattleBgm(): string {
     return this.config.mixedBattleBgm;
   }