add unit test for util function padInt (#175)

Co-authored-by: Viet Nguyen <vietnguyen@Viets-MacBook-Air.local>

src/utils.test.ts

@@ -1,5 +1,5 @@
 import { expect, describe, it } from "vitest";
-import { randomString } from "./utils";
+import { randomString, padInt } from "./utils";
 
 import Phaser from "phaser";
 
@@ -19,4 +19,26 @@ describe("utils", () => {
       expect(str1).toBe(str2);
     });
   });
+
+  describe("padInt", () => {
+    it("should return a string", () => {
+      const result = padInt(1, 10);
+      expect(typeof result).toBe('string');
+    });
+
+    it("should return a padded result with default padWith", () => {
+      const result = padInt(1, 3);
+      expect(result).toBe('001');
+    });
+
+    it("should return a padded result using a custom padWith", () => {
+      const result = padInt(1, 10, 'yes')
+      expect(result).toBe('yesyesyes1');
+    });
+
+    it("should return inputted value when zero length is entered", () => {
+      const result = padInt(1, 0);
+      expect(result).toBe('1')
+    })
+  });
 });