improvement: flow coverage

src/components/Post/Comments/Comments.js

@@ -1,8 +1,14 @@
+// @flow
 import React from 'react';
 import ReactDisqusComments from 'react-disqus-comments';
 import { useSiteMetadata } from '../../../hooks';
 
-const Comments = ({ postTitle, postSlug }) => {
+type Props = {
+  postTitle: string,
+  postSlug: string
+};
+
+const Comments = ({ postTitle, postSlug }: Props) => {
   const { url, disqusShortname } = useSiteMetadata();
 
   if (!disqusShortname) {

src/components/Post/Comments/Comments.test.js

@@ -1,13 +1,15 @@
+// @flow
 import React from 'react';
 import renderer from 'react-test-renderer';
 import { useStaticQuery, StaticQuery } from 'gatsby';
 import Comments from './Comments';
 import siteMetadata from '../../../../jest/__fixtures__/site-metadata';
+import type { RenderCallback } from '../../../types';
 
 describe('Comments', () => {
   beforeEach(() => {
     StaticQuery.mockImplementationOnce(
-      ({ render }) => (
+      ({ render }: RenderCallback) => (
         render(siteMetadata)
       ),
       useStaticQuery.mockReturnValue(siteMetadata)

src/components/Post/Comments/index.js

@@ -1 +1,2 @@
+// @flow
 export { default } from './Comments';