fix: test code (doesn't work)

Author: pan-no-mimi

1-js/05-data-types/05-array-methods/12-reduce-object/_js.view/test.js

@@ -8,13 +8,14 @@ describe("groupById", function() {
     ];
 
     assert.deepEqual(groupById(users), {
-      john: {id: 'john', name: "John Smith", age: 20}
+      john: {id: 'john', name: "John Smith", age: 20},
       ann: {id: 'ann', name: "Ann Smith", age: 24},
       pete: {id: 'pete', name: "Pete Peterson", age: 31},
     });
   });
 
   it("works with an empty array", function() {
-    assert.deepEqual(groupById(users), {});
+    let users_empty = [];
+    assert.deepEqual(groupById(users_empty), {});
   });
 });