Updating prerender script to use async/await

src/prerender.js

@@ -1,20 +1,31 @@
 import React from 'react';
 import { renderToString } from 'react-dom/server';
 import fs from 'fs';
+import util from 'util';
 import cheerio from 'cheerio';
 
 import './i18n';
 
-const pages = fs.readdirSync('./src/pages');
+const readdir = util.promisify(fs.readdir);
+const readFile = util.promisify(fs.readFile);
+const writeFile = util.promisify(fs.writeFile);
 
-pages.forEach(page => {
-  import(`./pages/${ page }/Component`).then(component => {
-    const Component = component.default;
-    const pagePath = `./build/${ page }.html`;
+readdir('./src/pages')
+  .then(pages => (
+    Promise.all(pages.map(async page => {
+      const Component = (await import(`./pages/${ page }/Component`)).default;
+      const pagePath = `./build/${ page }.html`;
 
-    const markup = cheerio.load(fs.readFileSync(pagePath));
+      const markup = cheerio.load(await readFile(pagePath));
 
-    markup('#root').html(renderToString(<Component/>));
-    fs.writeFileSync(pagePath, markup.html());
+      markup('#root').html(renderToString(<Component/>));
+      await writeFile(pagePath, markup.html());
+
+      console.log(`${ page } prerendered`); // eslint-disable-line no-console
+    }))
+  ))
+  .then(() => console.log('Done prerendering')) // eslint-disable-line no-console
+  .catch(e => {
+    console.log(e.toString()); // eslint-disable-line no-console
+    process.exit(1);
   });
-});