use fetch, tidy up

app/server.js

@@ -1,20 +1,10 @@
-import { resolve } from 'url';
 import polka from 'polka';
 import compression from 'compression';
 import sapper from 'sapper';
 import serve from 'serve-static';
-import fetch from 'node-fetch';
 import { routes } from './manifest/server.js';
 
-const { PORT } = process.env;
-
-// this allows us to do e.g. `fetch('/api/blog-posts')` on the server
-global.fetch = (url, opts) => {
-	url = resolve(`http://localhost:${PORT}/`, url);
-	return fetch(url, opts);
-};
-
-polka()
+polka() // You can also use Express
 	.use(compression({ threshold: 0 }))
 	.use(serve('assets'), sapper({ routes }))
-	.listen(PORT);
+	.listen(process.env.PORT);

routes/blog/[slug].html

@@ -59,7 +59,7 @@
 			// is called [slug].html
 			const { slug } = params;
 
-			return fetch(`blog/${slug}.json`).then(r => r.json()).then(post => {
+			return this.fetch(`blog/${slug}.json`).then(r => r.json()).then(post => {
 				return { post };
 			});
 		}

routes/blog/index.html

@@ -32,7 +32,7 @@
 		},
 
 		preload({ params, query }) {
-			return fetch(`blog.json`).then(r => r.json()).then(posts => {
+			return this.fetch(`blog.json`).then(r => r.json()).then(posts => {
 				return { posts };
 			});
 		}