Support priority ability activations

src/data/ability.ts

@@ -58,14 +58,16 @@ export class Ability implements Localizable {
   public generation: number;
   public isBypassFaint: boolean;
   public isIgnorable: boolean;
+  public isPriority: boolean;
   public attrs: AbAttr[];
   public conditions: AbAttrCondition[];
 
-  constructor(id: Abilities, generation: number) {
+  constructor(id: Abilities, generation: number, isPriority: boolean = false) {
     this.id = id;
 
     this.nameAppend = "";
     this.generation = generation;
+    this.isPriority = isPriority;
     this.attrs = [];
     this.conditions = [];
 
@@ -5999,6 +6001,21 @@ export function applyOnGainAbAttrs(pokemon: Pokemon, passive = false, simulated
 export function applyOnLoseAbAttrs(pokemon: Pokemon, passive = false, simulated = false, ...args: any[]): void {
   applySingleAbAttrs<PreLeaveFieldAbAttr>(pokemon, passive, PreLeaveFieldAbAttr, (attr, passive) => attr.applyPreLeaveField(pokemon, passive, simulated, [ ...args, true ]), args, true, simulated);
 }
+
+/**
+ * Applies only abilities that are priority or are not, based on parameters
+ * 
+ * @param priority If true, apply only priority abilities. If false, apply only non-priority abilities
+ */
+export function applyPriorityBasedAbAttrs(pokemon: Pokemon, priority: boolean, simulated: boolean = false, ...args: any[]) {
+  for (const passive of [ false, true ]) {
+    const ability: Ability = passive ? pokemon.getPassiveAbility() : pokemon.getAbility();
+    if (ability.isPriority == priority) {
+      applySingleAbAttrs<PostSummonAbAttr>(pokemon, passive, PostSummonAbAttr, (attr, passive) => attr.applyPostSummon(pokemon, passive, simulated, args), args, false, simulated)
+    }
+  }
+}
+
 function queueShowAbility(pokemon: Pokemon, passive: boolean): void {
   globalScene.unshiftPhase(new ShowAbilityPhase(pokemon.id, passive));
   globalScene.clearPhaseQueueSplice();
@@ -6887,7 +6904,7 @@ export function initAbilities() {
       .edgeCase(), //  interacts incorrectly with rock head. It's meant to switch abilities before recoil would apply so that a pokemon with rock head would lose rock head first and still take the recoil
     new Ability(Abilities.GORILLA_TACTICS, 8)
       .attr(GorillaTacticsAbAttr),
-    new Ability(Abilities.NEUTRALIZING_GAS, 8)
+    new Ability(Abilities.NEUTRALIZING_GAS, 8, true)
       .attr(PostSummonAddArenaTagAbAttr, ArenaTagType.NEUTRALIZING_GAS, 0)
       .attr(PreLeaveFieldRemoveSuppressAbilitiesSourceAbAttr)
       .attr(UncopiableAbilityAbAttr)
@@ -6920,14 +6937,14 @@ export function initAbilities() {
       .attr(PostVictoryStatStageChangeAbAttr, Stat.ATK, 1),
     new Ability(Abilities.GRIM_NEIGH, 8)
       .attr(PostVictoryStatStageChangeAbAttr, Stat.SPATK, 1),
-    new Ability(Abilities.AS_ONE_GLASTRIER, 8)
+    new Ability(Abilities.AS_ONE_GLASTRIER, 8, true)
       .attr(PostSummonMessageAbAttr, (pokemon: Pokemon) => i18next.t("abilityTriggers:postSummonAsOneGlastrier", { pokemonNameWithAffix: getPokemonNameWithAffix(pokemon) }))
       .attr(PreventBerryUseAbAttr)
       .attr(PostVictoryStatStageChangeAbAttr, Stat.ATK, 1)
       .attr(UncopiableAbilityAbAttr)
       .attr(UnswappableAbilityAbAttr)
       .attr(UnsuppressableAbilityAbAttr),
-    new Ability(Abilities.AS_ONE_SPECTRIER, 8)
+    new Ability(Abilities.AS_ONE_SPECTRIER, 8, true)
       .attr(PostSummonMessageAbAttr, (pokemon: Pokemon) => i18next.t("abilityTriggers:postSummonAsOneSpectrier", { pokemonNameWithAffix: getPokemonNameWithAffix(pokemon) }))
       .attr(PreventBerryUseAbAttr)
       .attr(PostVictoryStatStageChangeAbAttr, Stat.SPATK, 1)

src/field/pokemon.ts

@@ -2265,6 +2265,13 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     return false;
   }
 
+  /**
+   * @returns If either of the Pokemon's abilities have priority activation
+   */
+  public hasPriorityAbility() {
+    return [this.getAbility(), this.getPassiveAbility()].some(ability => ability.isPriority);
+  }
+
   /**
    * Gets the weight of the Pokemon with subtractive modifiers (Autotomize) happening first
    * and then multiplicative modifiers happening after (Heavy Metal and Light Metal)

src/phases/post-summon-phase.ts

@@ -1,31 +1,46 @@
 import { globalScene } from "#app/global-scene";
 import type { BattlerIndex } from "#app/battle";
-import { applyAbAttrs, applyPostSummonAbAttrs, CommanderAbAttr, PostSummonAbAttr } from "#app/data/ability";
+import { applyAbAttrs, applyPriorityBasedAbAttrs, CommanderAbAttr, PostSummonAbAttr } from "#app/data/ability";
 import { ArenaTrapTag } from "#app/data/arena-tag";
 import { StatusEffect } from "#app/enums/status-effect";
 import { PokemonPhase } from "./pokemon-phase";
 import { MysteryEncounterPostSummonTag } from "#app/data/battler-tags";
 import { BattlerTagType } from "#enums/battler-tag-type";
 import { Stat } from "#enums/stat";
+import { PriorityAbilityActivationPhase } from "#app/phases/priority-ability-activation-phase";
 
 export class PostSummonPhase extends PokemonPhase {
+  /** Represents whether or not this phase has already been placed in the correct (speed) order */
+  private ordered: boolean;
+
+  constructor(battlerIndex?: BattlerIndex, ordered = false) {
+    super(battlerIndex);
+
+    this.ordered = ordered;
+  }
+
   start() {
     super.start();
 
     const pokemon = this.getPokemon();
 
-    globalScene.phaseQueue;
+    if (
-    const fasterPhase = globalScene.findPhase(
+      !this.ordered &&
-      phase =>
+      globalScene.findPhase(phase => phase instanceof PostSummonPhase && phase.getPokemon() !== pokemon)
-        phase instanceof PostSummonPhase &&
+    ) {
-        phase.getPokemon().getEffectiveStat(Stat.SPD) > pokemon.getEffectiveStat(Stat.SPD),
+      globalScene.pushPhase(new PostSummonPhase(pokemon.getBattlerIndex(), true));
-    );
-    if (fasterPhase) {
-      globalScene.pushPhase(new PostSummonPhase(pokemon.getBattlerIndex()));
       globalScene.phaseQueue.sort(
         (phaseA: PostSummonPhase, phaseB: PostSummonPhase) =>
           phaseB.getPokemon().getEffectiveStat(Stat.SPD) - phaseA.getPokemon().getEffectiveStat(Stat.SPD),
       );
+      globalScene.phaseQueue.forEach((phase: PostSummonPhase) => {
+        phase.ordered = true;
+        const phasePokemon = phase.getPokemon();
+
+        if (phasePokemon.hasPriorityAbility()) {
+          globalScene.unshiftPhase(new PriorityAbilityActivationPhase(this.getPokemon().getBattlerIndex()));
+        }
+      });
       this.end();
       return;
     }
@@ -43,7 +58,7 @@ export class PostSummonPhase extends PokemonPhase {
       pokemon.lapseTag(BattlerTagType.MYSTERY_ENCOUNTER_POST_SUMMON);
     }
 
-    applyPostSummonAbAttrs(PostSummonAbAttr, pokemon);
+    applyPriorityBasedAbAttrs(pokemon, false);
     const field = pokemon.isPlayer() ? globalScene.getPlayerField() : globalScene.getEnemyField();
     for (const p of field) {
       applyAbAttrs(CommanderAbAttr, p, null, false);

src/phases/priority-ability-activation-phase.ts

@@ -0,0 +1,19 @@
+import { applyPriorityBasedAbAttrs } from "#app/data/ability";
+import { PokemonPhase } from "#app/phases/pokemon-phase";
+
+/**
+ * Phase to apply (post-summon) ability attributes for "priority" abilities
+ *
+ * Priority abilities activate before others and before hazards
+ *
+ * @see Example - {@link https://bulbapedia.bulbagarden.net/wiki/Neutralizing_Gas_(Ability) | Neutralizing Gas}
+ */
+export class PriorityAbilityActivationPhase extends PokemonPhase {
+  start() {
+    super.start();
+
+    applyPriorityBasedAbAttrs(this.getPokemon(), true);
+
+    this.end();
+  }
+}