From bc905f2af96516877e3aa9c97cb8eaf795a50af7 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Fri, 15 Apr 2022 15:41:50 -0400
Subject: [PATCH] Fix adapter-cloudflare-workers prerendering bug (#4626)

* feat: allow adapter-cloudflare-workers to take esbuild options

* chore: add changeset

* fix: prerendered page resolution

* chore: update changeset

* chore: run prettier

* update

* Update .changeset/chilly-cars-battle.md

Co-authored-by: Joe Harlow <joe@f5.io>
---
 .changeset/chilly-cars-battle.md              |  5 +++++
 .../adapter-cloudflare-workers/ambient.d.ts   |  2 +-
 .../adapter-cloudflare-workers/files/entry.js | 21 ++++++++++++-------
 packages/adapter-cloudflare-workers/index.js  |  4 +++-
 4 files changed, 23 insertions(+), 9 deletions(-)
 create mode 100644 .changeset/chilly-cars-battle.md

diff --git a/.changeset/chilly-cars-battle.md b/.changeset/chilly-cars-battle.md
new file mode 100644
index 000000000000..c37ac72d99ad
--- /dev/null
+++ b/.changeset/chilly-cars-battle.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-cloudflare-workers': patch
+---
+
+- Fix an issue related to prerendered pages incorrectly resolving in @sveltejs/adapter-cloudflare-workers
diff --git a/packages/adapter-cloudflare-workers/ambient.d.ts b/packages/adapter-cloudflare-workers/ambient.d.ts
index a1381f25f04d..78ceb0e62887 100644
--- a/packages/adapter-cloudflare-workers/ambient.d.ts
+++ b/packages/adapter-cloudflare-workers/ambient.d.ts
@@ -6,7 +6,7 @@ declare module 'MANIFEST' {
 	import { SSRManifest } from '@sveltejs/kit';
 
 	export const manifest: SSRManifest;
-	export const prerendered: Set<string>;
+	export const prerendered: Map<string, { file: string }>;
 }
 
 declare module '__STATIC_CONTENT_MANIFEST' {
diff --git a/packages/adapter-cloudflare-workers/files/entry.js b/packages/adapter-cloudflare-workers/files/entry.js
index ab6d9b602d41..96af27c22634 100644
--- a/packages/adapter-cloudflare-workers/files/entry.js
+++ b/packages/adapter-cloudflare-workers/files/entry.js
@@ -1,6 +1,6 @@
 import { Server } from 'SERVER';
 import { manifest, prerendered } from 'MANIFEST';
-import { getAssetFromKV } from '@cloudflare/kv-asset-handler';
+import { getAssetFromKV, mapRequestToAsset } from '@cloudflare/kv-asset-handler';
 import static_asset_manifest_json from '__STATIC_CONTENT_MANIFEST';
 const static_asset_manifest = JSON.parse(static_asset_manifest_json);
 
@@ -21,9 +21,8 @@ export default {
 		if (url.pathname.startsWith(prefix)) {
 			/** @type {Response} */
 			const res = await get_asset_from_kv(req, env, context);
-			if (is_error(res.status)) {
-				return res;
-			}
+			if (is_error(res.status)) return res;
+
 			return new Response(res.body, {
 				headers: {
 					// include original cache headers, minus cache-control which
@@ -50,7 +49,14 @@ export default {
 			manifest.assets.has(file + '/index.html') ||
 			prerendered.has(pathname || '/')
 		) {
-			return get_asset_from_kv(req, env, context);
+			return get_asset_from_kv(req, env, context, (request, options) => {
+				if (prerendered.has(pathname || '/')) {
+					url.pathname = '/' + prerendered.get(pathname || '/').file;
+					return new Request(url.toString(), request);
+				}
+
+				return mapRequestToAsset(request, options);
+			});
 		}
 
 		// dynamically-generated pages
@@ -72,7 +78,7 @@ export default {
  * @param {any} env
  * @param {any} context
  */
-async function get_asset_from_kv(req, env, context) {
+async function get_asset_from_kv(req, env, context, map = mapRequestToAsset) {
 	try {
 		return await getAssetFromKV(
 			{
@@ -83,7 +89,8 @@ async function get_asset_from_kv(req, env, context) {
 			},
 			{
 				ASSET_NAMESPACE: env.__STATIC_CONTENT,
-				ASSET_MANIFEST: static_asset_manifest
+				ASSET_MANIFEST: static_asset_manifest,
+				mapRequestToAsset: map
 			}
 		);
 	} catch (e) {
diff --git a/packages/adapter-cloudflare-workers/index.js b/packages/adapter-cloudflare-workers/index.js
index 94732b553f06..045eef0b8b20 100644
--- a/packages/adapter-cloudflare-workers/index.js
+++ b/packages/adapter-cloudflare-workers/index.js
@@ -49,7 +49,9 @@ export default function (options = {}) {
 				`${tmp}/manifest.js`,
 				`export const manifest = ${builder.generateManifest({
 					relativePath
-				})};\n\nexport const prerendered = new Set(${JSON.stringify(builder.prerendered.paths)});\n`
+				})};\n\nexport const prerendered = new Map(${JSON.stringify(
+					Array.from(builder.prerendered.pages.entries())
+				)});\n`
 			);
 
 			await esbuild.build({