Merge pull request #105 from preactjs/feat/patched-fetch-response

feat: Return proper `Response` from patched `fetch` during prerender

Author: rschristian

demo/src/components/LocalFetch.tsx

@@ -4,7 +4,8 @@ const cache = new Map();
 
 async function load(url: string) {
 	const res = await fetch(url);
-	return await res.text();
+	if (res.ok) return await res.text();
+	throw new Error(`Failed to fetch ${url}!`);
 }
 
 function useFetch(url: string) {

src/prerender.ts

@@ -169,15 +169,20 @@ export function PrerenderPlugin({
 			// @ts-ignore
 			globalThis.fetch = async (url: string, opts: RequestInit | undefined) => {
 				if (/^\//.test(url)) {
-					const text = () =>
-						fs.readFile(
-							`${path.join(
-								viteConfig.root,
-								viteConfig.build.outDir,
-							)}/${url.replace(/^\//, "")}`,
-							"utf-8",
+					try {
+						return new Response(
+							await fs.readFile(
+								`${path.join(
+									viteConfig.root,
+									viteConfig.build.outDir,
+								)}/${url.replace(/^\//, "")}`,
+								"utf-8",
+							),
 						);
-					return { text, json: () => text().then(JSON.parse) };
+					} catch (e: any) {
+						if (e.code !== "ENOENT") throw e;
+						return new Response(null, { status: 404 });
+					}
 				}
 
 				return nodeFetch(url, opts);
@@ -291,7 +296,7 @@ export function PrerenderPlugin({
 				if (result.links) {
 					for (let url of result.links) {
 						const parsed = new URL(url, "http://localhost");
-						url = parsed.pathname.replace(/\/$/, '') || '/';
+						url = parsed.pathname.replace(/\/$/, "") || "/";
 						// ignore external links and ones we've already picked up
 						if (seen.has(url) || parsed.origin !== "http://localhost") continue;
 						seen.add(url);