[BUG] Fixes #5288 Clowning Around doesn’t check if Pokemon

already  has the ability

When offering the same ability a Pokemon
already has, a menu should
now appear informing the user. The user can then choose a different
Pokemon or proceed to give the same ability anyway.

src/data/mystery-encounters/encounters/clowning-around-encounter.ts

@@ -467,14 +467,52 @@ function displayYesNoOptions(resolve) {
   globalScene.ui.setModeWithoutClear(UiMode.OPTION_SELECT, config, null, true);
 }
 
+function handleRepeatedAbility(resolve, pokemon: PlayerPokemon, ability: Abilities) {
+  showEncounterText("Your pokemon already has this ability. Are you sure you want to apply it?");
+  const fullOptions = [
+    {
+      label: i18next.t("menu:yes"),
+      handler: () => {
+        applyAbilityOverrideToPokemon(pokemon, ability, true);
+        globalScene.ui.setMode(UiMode.MESSAGE).then(() => resolve(true));
+        return true;
+      },
+    },
+    {
+      label: i18next.t("menu:no"),
+      handler: () => {
+        onYesAbilitySwap(resolve);
+        return true;
+      },
+    },
+  ];
+
+  const config: OptionSelectConfig = {
+    options: fullOptions,
+    maxOptions: 7,
+    yOffset: 0,
+  };
+  globalScene.ui.setModeWithoutClear(UiMode.OPTION_SELECT, config, null, true);
+}
+
 function onYesAbilitySwap(resolve) {
   const onPokemonSelected = (pokemon: PlayerPokemon) => {
     // Do ability swap
     const encounter = globalScene.currentBattle.mysteryEncounter!;
 
-    applyAbilityOverrideToPokemon(pokemon, encounter.misc.ability);
+    // Choose a random ability, to give a pokemon on the end of a battle
+    const randomAbility = encounter.misc.ability;
+    const newAbility = applyAbilityOverrideToPokemon(pokemon, randomAbility, false);
     encounter.setDialogueToken("chosenPokemon", pokemon.getNameToRender());
-    globalScene.ui.setMode(UiMode.MESSAGE).then(() => resolve(true));
+
+    globalScene.ui.setMode(UiMode.MESSAGE).then(() => {
+      // if Pokemon already has the same Ability
+      if (!newAbility) {
+        handleRepeatedAbility(resolve, pokemon, randomAbility);
+      } else {
+        resolve(true);
+      }
+    });
   };
 
   const onPokemonNotSelected = () => {

src/data/mystery-encounters/utils/encounter-pokemon-utils.ts

@@ -1023,14 +1023,22 @@ export function isPokemonValidForEncounterOptionSelection(
 /**
  * Permanently overrides the ability (not passive) of a pokemon.
  * If the pokemon is a fusion, instead overrides the fused pokemon's ability.
+ * @param ability
+ * @param pokemon
+ * @param flagAcceptAbility
  */
-export function applyAbilityOverrideToPokemon(pokemon: Pokemon, ability: Abilities) {
+export function applyAbilityOverrideToPokemon(pokemon: Pokemon, ability: Abilities, flagAcceptAbility: boolean) {
-  if (pokemon.isFusion()) {
+  const isFusion = pokemon.isFusion();
-    if (!pokemon.fusionCustomPokemonData) {
+  const data = isFusion
-      pokemon.fusionCustomPokemonData = new CustomPokemonData();
+    ? (pokemon.fusionCustomPokemonData ??= new CustomPokemonData())
-    }
+    : (pokemon.customPokemonData ??= new CustomPokemonData());
-    pokemon.fusionCustomPokemonData.ability = ability;
+
-  } else {
+  const shouldOverride = data.ability !== ability || flagAcceptAbility;
-    pokemon.customPokemonData.ability = ability;
+
+  if (shouldOverride) {
+    data.ability = ability;
+    return true;
   }
+
+  return false;
 }

test/mystery-encounter/encounters/clowning-around-encounter.test.ts

@@ -37,6 +37,7 @@ import { CommandPhase } from "#app/phases/command-phase";
 import { MovePhase } from "#app/phases/move-phase";
 import { SelectModifierPhase } from "#app/phases/select-modifier-phase";
 import { NewBattlePhase } from "#app/phases/new-battle-phase";
+import { allAbilities } from "#app/data/data-lists";
 
 const namespace = "mysteryEncounters/clowningAround";
 const defaultParty = [Species.LAPRAS, Species.GENGAR, Species.ABRA];
@@ -234,6 +235,59 @@ describe("Clowning Around - Mystery Encounter", () => {
       const leadPokemon = scene.getPlayerParty()[0];
       expect(leadPokemon.customPokemonData?.ability).toBe(abilityToTrain);
     });
+
+    it("should let the player know their pokemon already has the ability and accept it", async () => {
+      await game.runToMysteryEncounter(MysteryEncounterType.CLOWNING_AROUND, defaultParty);
+      await runMysteryEncounterToEnd(game, 1, undefined, true);
+      await skipBattleRunMysteryEncounterRewardsPhase(game);
+      await game.phaseInterceptor.to(SelectModifierPhase, false);
+      expect(scene.getCurrentPhase()?.constructor.name).toBe(SelectModifierPhase.name);
+      await game.phaseInterceptor.run(SelectModifierPhase);
+
+      const leadPokemon = scene.getPlayerParty()[0];
+      // offer Prankster abiliy for winning the battle
+      const abilityToTrain = Abilities.PRANKSTER;
+
+      game.onNextPrompt("PostMysteryEncounterPhase", UiMode.MESSAGE, () => {
+        game.scene.ui.getHandler().processInput(Button.ACTION);
+      });
+
+      // Give fto the first Pokemon the Prankster ability
+      vi.spyOn(leadPokemon, "getAbility").mockReturnValue(allAbilities[Abilities.PRANKSTER]);
+
+      // Run to ability train option selection
+      const optionSelectUiHandler = game.scene.ui.handlers[UiMode.OPTION_SELECT] as OptionSelectUiHandler;
+      vi.spyOn(optionSelectUiHandler, "show");
+      const partyUiHandler = game.scene.ui.handlers[UiMode.PARTY] as PartyUiHandler;
+      vi.spyOn(partyUiHandler, "show");
+      const optionSelectUiHandlerRepeatedAbility = game.scene.ui.handlers[
+        UiMode.OPTION_SELECT
+      ] as OptionSelectUiHandler;
+      vi.spyOn(optionSelectUiHandlerRepeatedAbility, "show");
+      game.endPhase();
+      await game.phaseInterceptor.to(PostMysteryEncounterPhase);
+      expect(scene.getCurrentPhase()?.constructor.name).toBe(PostMysteryEncounterPhase.name);
+
+      // Wait for Yes/No confirmation to appear -> accepting the Ability
+      await vi.waitFor(() => expect(optionSelectUiHandler.show).toHaveBeenCalled());
+      // Select "Yes" on train ability
+      optionSelectUiHandler.processInput(Button.ACTION);
+      // Select first pokemon in party to train
+      await vi.waitFor(() => expect(partyUiHandler.show).toHaveBeenCalled());
+      partyUiHandler.processInput(Button.ACTION);
+      // Click "Select" on Pokemon
+      partyUiHandler.processInput(Button.ACTION);
+      // Wait for Yes/No confirmation to appear -> Accepting the Ability, besides being repeated
+      await vi.waitFor(() => expect(optionSelectUiHandlerRepeatedAbility.show).toHaveBeenCalled());
+      // Select "Yes" on train the same ability as before
+      optionSelectUiHandlerRepeatedAbility.processInput(Button.ACTION);
+
+      // Stop next battle before it runs
+      await game.phaseInterceptor.to(NewBattlePhase, false);
+      //game.override.ability(Abilities.PRANKSTER);
+
+      expect(leadPokemon.getAbility().id).toBe(abilityToTrain);
+    });
   });
 
   describe("Option 2 - Remain Unprovoked", () => {