add null and undefined tests

Author: dangowans

test/1.basicTypes.test.js

@@ -158,4 +158,12 @@ await describe('getObjectDifference() basic types', async () => {
             });
         });
     });
+    await it('should compare undefined values', () => {
+        const result = getObjectDifference(undefined, undefined);
+        assert.strictEqual(result.length, 0, 'length of comparison results');
+    });
+    await it('should compare null values', () => {
+        const result = getObjectDifference(null, null);
+        assert.strictEqual(result.length, 0, 'length of comparison results');
+    });
 });

test/1.basicTypes.test.ts

@@ -210,4 +210,16 @@ await describe('getObjectDifference() basic types', async () => {
       })
     })
   })
+
+  await it('should compare undefined values', () => {
+    const result = getObjectDifference(undefined, undefined)
+
+    assert.strictEqual(result.length, 0, 'length of comparison results')
+  })
+
+  await it('should compare null values', () => {
+    const result = getObjectDifference(null, null)
+
+    assert.strictEqual(result.length, 0, 'length of comparison results')
+  })
 })