[Bug] Fixing Tera Starstorm for first turn of terastallization (#5658)

* Updating tera starstorm targeting condition so that it is a spread move on the turn that terastallization happens

* added new unit tests to verify behavior of tera starstorm under non-tera conditions as well as on terastallization turns

src/data/moves/move.ts

@@ -11205,7 +11205,7 @@ export function initMoves() {
     new AttackMove(Moves.TERA_STARSTORM, PokemonType.NORMAL, MoveCategory.SPECIAL, 120, 100, 5, -1, 0, 9)
       .attr(TeraMoveCategoryAttr)
       .attr(TeraStarstormTypeAttr)
-      .attr(VariableTargetAttr, (user, target, move) => user.hasSpecies(Species.TERAPAGOS) && user.isTerastallized ? MoveTarget.ALL_NEAR_ENEMIES : MoveTarget.NEAR_OTHER)
+      .attr(VariableTargetAttr, (user, target, move) => user.hasSpecies(Species.TERAPAGOS) && (user.isTerastallized || globalScene.currentBattle.preTurnCommands[user.getFieldIndex()]?.command === Command.TERA) ? MoveTarget.ALL_NEAR_ENEMIES : MoveTarget.NEAR_OTHER)
       .partial(), /** Does not ignore abilities that affect stats, relevant in determining the move's category {@see TeraMoveCategoryAttr} */
     new AttackMove(Moves.FICKLE_BEAM, PokemonType.DRAGON, MoveCategory.SPECIAL, 80, 100, 5, 30, 0, 9)
       .attr(PreMoveMessageAttr, doublePowerChanceMessageFunc)

test/moves/tera_starstorm.test.ts

@@ -69,6 +69,40 @@ describe("Moves - Tera Starstorm", () => {
     expect(enemyField.every(pokemon => pokemon.isFullHp())).toBe(false);
   });
 
+  it("targets both opponents in a double battle when used by Terapagos immediately after terastallizing", async () => {
+    await game.classicMode.startBattle([Species.TERAPAGOS]);
+
+    const terapagos = game.scene.getPlayerParty()[0];
+    terapagos.isTerastallized = false;
+
+    game.move.selectWithTera(Moves.TERA_STARSTORM, 0);
+
+    await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.ENEMY, BattlerIndex.ENEMY_2]);
+
+    const enemyField = game.scene.getEnemyField();
+
+    // Terapagos in Stellar Form should hit both targets
+    await game.phaseInterceptor.to("MoveEndPhase");
+    expect(enemyField.some(pokemon => pokemon.isFullHp())).toBe(false);
+  });
+
+  it("targets only one opponent in a double battle when used by Terapagos without terastallizing", async () => {
+    await game.classicMode.startBattle([Species.TERAPAGOS]);
+
+    const terapagos = game.scene.getPlayerParty()[0];
+    terapagos.isTerastallized = false;
+
+    game.move.select(Moves.TERA_STARSTORM, 0, BattlerIndex.ENEMY);
+
+    await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.ENEMY, BattlerIndex.ENEMY_2]);
+
+    const enemyField = game.scene.getEnemyField();
+
+    // Terapagos in Stellar Form should hit both targets
+    await game.phaseInterceptor.to("MoveEndPhase");
+    expect(enemyField.some(pokemon => pokemon.isFullHp())).toBe(true);
+  });
+
   it("applies the effects when Terapagos in Stellar Form is fused with another Pokemon", async () => {
     await game.classicMode.startBattle([Species.TERAPAGOS, Species.CHARMANDER, Species.MAGIKARP]);
 

test/testUtils/helpers/moveHelper.ts

@@ -65,6 +65,33 @@ export class MoveHelper extends GameManagerHelper {
     }
   }
 
+  /**
+   * Select the move to be used by the given Pokemon(-index), **which will also terastallize on this turn**.
+   * Triggers during the next {@linkcode CommandPhase}
+   * @param move - the move to use
+   * @param pkmIndex - the pokemon index. Relevant for double-battles only (defaults to 0)
+   * @param targetIndex - The {@linkcode BattlerIndex} of the Pokemon to target for single-target moves, or `null` if a manual call to `selectTarget()` is required
+   */
+  public selectWithTera(move: Moves, pkmIndex: 0 | 1 = 0, targetIndex?: BattlerIndex | null) {
+    const movePosition = getMovePosition(this.game.scene, pkmIndex, move);
+    this.game.scene.getPlayerParty()[pkmIndex].isTerastallized = false;
+
+    this.game.onNextPrompt("CommandPhase", Mode.COMMAND, () => {
+      this.game.scene.ui.setMode(
+        Mode.FIGHT,
+        (this.game.scene.getCurrentPhase() as CommandPhase).getFieldIndex(),
+        Command.TERA,
+      );
+    });
+    this.game.onNextPrompt("CommandPhase", Mode.FIGHT, () => {
+      (this.game.scene.getCurrentPhase() as CommandPhase).handleCommand(Command.TERA, movePosition, false);
+    });
+
+    if (targetIndex !== null) {
+      this.game.selectTarget(movePosition, targetIndex);
+    }
+  }
+
   /**
    * Forces the Paralysis or Freeze status to activate on the next move by temporarily mocking {@linkcode Overrides.STATUS_ACTIVATION_OVERRIDE},
    * advancing to the next `MovePhase`, and then resetting the override to `null`