Repair negative quest scrolls on (gem)purchase (#11399)

* Fix: Reset negative quest scrolls number to zero on purchase(gem)

* Refactor: rename website/common/script/ops/buy/buyQuest.js to website/common/script/ops/buy/buyQuestGold.js and update related files

* Test: add two tests related to negative quest scrolls

website/common/script/ops/buy/buy.js

@@ -6,7 +6,7 @@ import {BuyArmoireOperation} from './buyArmoire';
 import {BuyHealthPotionOperation} from './buyHealthPotion';
 import {BuyMarketGearOperation} from './buyMarketGear';
 import buyMysterySet from './buyMysterySet';
-import {BuyQuestWithGoldOperation} from './buyQuest';
+import {BuyQuestWithGoldOperation} from './buyQuestGold';
 import {BuySpellOperation} from './buySpell';
 import purchaseOp from './purchase';
 import hourglassPurchase from './hourglassPurchase';

website/common/script/ops/buy/buyQuestGem.js

@@ -46,7 +46,7 @@ export class BuyQuestWithGemOperation extends AbstractGemItemOperation {
   }
 
   executeChanges (user, item, req) {
-    user.items.quests[item.key] = user.items.quests[item.key] || 0;
+    if (!user.items.quests[item.key] || user.items.quests[item.key] < 0) user.items.quests[item.key] = 0;
     user.items.quests[item.key] += this.quantity;
     if (user.markModified) user.markModified('items.quests');