Refactor tally function to use Object.hasOwn for item counting and add test for 'toString' items

Author: ChinweP

Sprint-2/implement/tally.js

@@ -6,7 +6,7 @@ function tally(items) {
   const counts = {};
 
   for (const item of items) {
-    if (counts[item] === undefined) {
+    if (!Object.hasOwn(counts, item)) {
       counts[item] = 1;
     } else {
       counts[item] = counts[item] + 1;

Sprint-2/implement/tally.test.js

@@ -44,3 +44,9 @@ test("tally throws an error for invalid input", () => {
   expect(() => tally("hello")).toThrow();
 });
 
+
+test("tally counts items named toString", () => {
+  expect(tally(["toString", "toString"])).toEqual({
+    toString: 2,
+  });
+});