feat: add upgrade scrolls

src/engine/systems/UpgradeManager.ts

@@ -0,0 +1,64 @@
+import type { Item, WeaponItem, ArmourItem } from "../../core/types";
+
+/**
+ * Manages item upgrade logic for applying upgrade scrolls.
+ */
+export class UpgradeManager {
+  
+  /**
+   * Checks if an item can be upgraded (weapons and armour only).
+   */
+  static canUpgrade(item: Item): boolean {
+    return item.type === "Weapon" || 
+           item.type === "BodyArmour" || 
+           item.type === "Helmet" || 
+           item.type === "Gloves" || 
+           item.type === "Boots";
+  }
+  
+  /**
+   * Applies an upgrade to an item, increasing all stats by +1.
+   * Returns true if successful.
+   */
+  static applyUpgrade(item: Item): boolean {
+    if (!this.canUpgrade(item)) {
+      return false;
+    }
+    
+    // Increment upgrade level
+    const currentLevel = item.upgradeLevel ?? 0;
+    item.upgradeLevel = currentLevel + 1;
+    
+    // Update item name with level suffix
+    // Remove any existing upgrade suffix first
+    const baseName = item.name.replace(/\s*\+\d+$/, "");
+    item.name = `${baseName} +${item.upgradeLevel}`;
+    
+    // Increase all numeric stats by +1
+    if (item.type === "Weapon") {
+      const weaponItem = item as WeaponItem;
+      if (weaponItem.stats.attack !== undefined) {
+        weaponItem.stats.attack += 1;
+      }
+    } else if (item.type === "BodyArmour" || item.type === "Helmet" || 
+               item.type === "Gloves" || item.type === "Boots") {
+      const armourItem = item as ArmourItem;
+      if (armourItem.stats.defense !== undefined) {
+        armourItem.stats.defense += 1;
+      }
+    }
+    
+    return true;
+  }
+  
+  /**
+   * Gets the display name for an item including upgrade level.
+   */
+  static getDisplayName(item: Item): string {
+    if (item.upgradeLevel && item.upgradeLevel > 0) {
+      const baseName = item.name.replace(/\s*\+\d+$/, "");
+      return `${baseName} +${item.upgradeLevel}`;
+    }
+    return item.name;
+  }
+}

src/engine/systems/__tests__/UpgradeManager.test.ts

@@ -0,0 +1,66 @@
+import { describe, it, expect } from 'vitest';
+import { UpgradeManager } from '../UpgradeManager';
+import { createMeleeWeapon, createArmour, createConsumable } from '../../../core/config/Items';
+import type { WeaponItem, ArmourItem } from '../../../core/types';
+
+describe('UpgradeManager', () => {
+    it('should correctly identify upgradeable items', () => {
+        const sword = createMeleeWeapon("iron_sword");
+        const armor = createArmour("leather_armor");
+        const potion = createConsumable("health_potion");
+
+        expect(UpgradeManager.canUpgrade(sword)).toBe(true);
+        expect(UpgradeManager.canUpgrade(armor)).toBe(true);
+        expect(UpgradeManager.canUpgrade(potion)).toBe(false);
+    });
+
+    it('should upgrade weapon stats and name', () => {
+        const sword = createMeleeWeapon("iron_sword") as WeaponItem;
+        const initialAttack = sword.stats.attack!;
+        const initialName = sword.name;
+
+        const success = UpgradeManager.applyUpgrade(sword);
+
+        expect(success).toBe(true);
+        expect(sword.stats.attack).toBe(initialAttack + 1);
+        expect(sword.upgradeLevel).toBe(1);
+        expect(sword.name).toBe(`${initialName} +1`);
+    });
+
+    it('should upgrade armour stats and name', () => {
+        const armor = createArmour("leather_armor") as ArmourItem;
+        const initialDefense = armor.stats.defense!;
+        const initialName = armor.name;
+
+        const success = UpgradeManager.applyUpgrade(armor);
+
+        expect(success).toBe(true);
+        expect(armor.stats.defense).toBe(initialDefense + 1);
+        expect(armor.upgradeLevel).toBe(1);
+        expect(armor.name).toBe(`${initialName} +1`);
+    });
+
+    it('should handle sequential upgrades', () => {
+        const sword = createMeleeWeapon("iron_sword") as WeaponItem;
+        const initialAttack = sword.stats.attack!;
+        const initialName = sword.name;
+
+        UpgradeManager.applyUpgrade(sword); // +1
+        UpgradeManager.applyUpgrade(sword); // +2
+
+        expect(sword.stats.attack).toBe(initialAttack + 2);
+        expect(sword.upgradeLevel).toBe(2);
+        expect(sword.name).toBe(`${initialName} +2`);
+    });
+
+    it('should not upgrade non-upgradeable items', () => {
+        const potion = createConsumable("health_potion");
+        const initialName = potion.name;
+
+        const success = UpgradeManager.applyUpgrade(potion);
+
+        expect(success).toBe(false);
+        expect(potion.upgradeLevel).toBeUndefined();
+        expect(potion.name).toBe(initialName);
+    });
+});

src/engine/world/generator.ts

@@ -6,7 +6,8 @@ import {
   createConsumable, 
   createMeleeWeapon, 
   createRangedWeapon, 
-  createArmour 
+  createArmour,
+  createUpgradeScroll
 } from "../../core/config/Items";
 import { seededRandom } from "../../core/math";
 import * as ROT from "rot-js";
@@ -62,7 +63,8 @@ export function generateWorld(floor: number, runState: RunState): { world: World
           createMeleeWeapon("iron_sword", "sharp"),  // Sharp sword variant
           createConsumable("throwing_dagger", 3),
           createRangedWeapon("pistol"),
-          createArmour("leather_armor", "heavy")  // Heavy armour variant
+          createArmour("leather_armor", "heavy"),  // Heavy armour variant
+          createUpgradeScroll(2) // 2 Upgrade scrolls
         ] : [])
       ] 
     },