strengthen array validation and update contains logic to reject arrays.

Author: fayaz551

Sprint-2/implement/contains.js

@@ -1,4 +1,8 @@
 function contains(obj, key) {
+  if (obj === null || typeof obj !== "object" || Array.isArray(obj)) {
+    return false;
+  }
+  
   return Object.hasOwn(obj, key);
 }
 

Sprint-2/implement/contains.test.js

@@ -50,6 +50,10 @@ test("contains on object with non-existent property returns false", () => {
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
-test("contains on invalid parameters returns false", () => {
-    expect(contains([], "a")).toBe(false);
-  });
+
+  test("contains on invalid parameters returns false", () => {
+  // We use an index that EXISTS in the array (0)
+  // If the function returns false, we know it's because it rejected the ARRAY type
+  expect(contains(["test"], 0)).toBe(false);
+  expect(contains(null, "a")).toBe(false);
+});