test(ArticleComments): add snapshot testing

src/components/Article/ArticleComments.test.tsx

@@ -0,0 +1,22 @@
+import React from 'react';
+import { create } from 'react-test-renderer';
+import ArticleComments from './ArticleComments';
+
+const commentUrl = 'https://example.com';
+
+describe('ArticleComments', () => {
+  beforeAll(() => {
+    jest.spyOn(document, 'getElementById').mockImplementation((elementId) => {
+      return document.createElement(`#${elementId}`);
+    });
+  });
+
+  afterAll(() => {
+    (document.getElementById as unknown as jest.SpyInstance).mockRestore();
+  });
+
+  test('should render correctly (snapshot)', () => {
+    const tree = create(<ArticleComments url={commentUrl} />).toJSON();
+    expect(tree).toMatchSnapshot();
+  });
+});