diff --git a/packages/util/__tests__/lib/data.test.ts b/packages/util/__tests__/lib/data.test.ts
new file mode 100644
index 0000000..f385101
--- /dev/null
+++ b/packages/util/__tests__/lib/data.test.ts
@@ -0,0 +1,47 @@
+import {
+  deepClone
+} from '../../src/lib/data';
+
+
+describe('@idraw/util: lib/data', () => {
+  const json = {
+    num: 123,
+    str: 'abc',
+    bool: true,
+    arr: [
+      {
+        num: 1,
+        str: 'a',
+        bool: false,
+      },
+      {
+        num: 2,
+        str: 'b',
+        bool: false,
+      }
+    ],
+    json: {
+      num: 10,
+      str: 'aaaa',
+      bool: false,
+      json: {
+        num: 11,
+        str: 'bbbb',
+        bool: false,
+      }
+    }
+  }
+
+  const json2 = deepClone(json);
+  json2.json.json.num *= 2;
+
+  test('deepClone', async () => {
+    const result = deepClone(json);
+    result.json.json.num *= 2;
+    expect(result).toStrictEqual(json2);
+  });
+
+  
+
+});
+