fix: add integrity test

src/integrity.test.ts

@@ -0,0 +1,9 @@
+import { stat } from 'fs/promises';
+
+describe('Integrity tests', () => {
+  describe('package-lock.json', () => {
+    it('does not exist', async () => {
+      await expect(stat(`${process.cwd()}/package-lock.json`)).rejects.toThrowError();
+    });
+  });
+});