fix: decode keys and values in parseQueryString and add test case

Author: jakr-s

Sprint-2/implement/querystring.js

@@ -7,7 +7,9 @@ function parseQueryString(queryString) {
 
   for (const pair of keyValuePairs) {
     const [key, ...valueParts] = pair.split("=");
-    queryParams[key] = valueParts.join("=");
+    const decodedKey = decodeURIComponent(key);
+    const decodedValue = decodeURIComponent(valueParts.join("="));
+    queryParams[decodedKey] = decodedValue;
   }
 
   return queryParams;

Sprint-2/implement/querystring.test.js

@@ -22,3 +22,10 @@ test("handles key without value", () => {
     key3: "value3",
   });
 });
+
+test("should decode URL-encoded query strings", () => {
+  const queryString = "tags%5B%5D=hello%20world";
+  const expected = { "tags[]": "hello world" };
+  const result = parseQueryString(queryString);
+  expect(result).toEqual(expected);
+});