test: added test for enumObject.

src/util/__tests__/enumObject.test.ts

@@ -0,0 +1,24 @@
+import { enumObject } from '../objects';
+
+test('it should ignore and not crash with non-object', () => {
+  expect(Array.from(enumObject('string' as never))).toEqual([]);
+});
+
+test('it should ignore and not crash with null', () => {
+  expect(Array.from(enumObject(null))).toEqual([]);
+});
+
+test('it be able to iterate object', () => {
+  expect(Array.from(enumObject({ a: '1', b: '2' }))).toMatchInlineSnapshot(`
+    [
+      [
+        "a",
+        "1",
+      ],
+      [
+        "b",
+        "2",
+      ],
+    ]
+  `);
+});