feat: SPA redirect

packages/hydrogen/src/entry-client.tsx

@@ -1,7 +1,7 @@
 import React, {Suspense, useState} from 'react';
 // @ts-ignore
 import {createRoot} from 'react-dom';
-import {BrowserRouter} from 'react-router-dom';
+import {BrowserRouter, Redirect} from 'react-router-dom';
 import type {ClientHandler} from './types';
 import {ErrorBoundary} from 'react-error-boundary';
 import {HelmetProvider} from 'react-helmet-async';
@@ -35,7 +35,8 @@ function Content({clientWrapper: ClientWrapper}: {clientWrapper: any}) {
     pathname: window.location.pathname,
     search: window.location.search,
   });
-  const response = useServerResponse(serverState);
+
+  const response = useServerResponse(serverState).read();
 
   return (
     <ServerStateProvider
@@ -46,8 +47,12 @@ function Content({clientWrapper: ClientWrapper}: {clientWrapper: any}) {
         <HelmetProvider>
           <BrowserRouter>
             <ServerStateRouter />
-            {/* @ts-ignore */}
-            <ClientWrapper>{response.read()}</ClientWrapper>
+            {response.redirect ? (
+              <Redirect to={response.redirect} />
+            ) : (
+              /* @ts-ignore */
+              <ClientWrapper>{response}</ClientWrapper>
+            )}
           </BrowserRouter>
         </HelmetProvider>
       </QueryProvider>

packages/hydrogen/src/entry-server.tsx

@@ -20,6 +20,7 @@ import {ServerComponentResponse} from './framework/Hydration/ServerComponentResp
 import {ServerComponentRequest} from './framework/Hydration/ServerComponentRequest.server';
 import {dehydrate} from 'react-query/hydration';
 import {getCacheControlHeader} from './framework/cache';
+import type {ServerResponse} from 'http';
 
 /**
  * react-dom/unstable-fizz provides different entrypoints based on runtime:
@@ -118,6 +119,14 @@ const renderHydrogen: ServerHandler = (App, hook) => {
             componentResponse.cacheControlHeader
           );
 
+          if (componentResponse.customHead) {
+            writeHeadToServerResponse(componentResponse, response);
+            if (response.statusCode >= 300 && response.statusCode < 400) {
+              // Redirect
+              return response.end();
+            }
+          }
+
           if (!componentResponse.canStream()) return;
 
           response.statusCode = didError ? 500 : 200;
@@ -205,6 +214,15 @@ const renderHydrogen: ServerHandler = (App, hook) => {
          * `template` and `script` tags inserted and rendered as part of the hydration response.
          */
         onCompleteAll() {
+          if (componentResponse.customHead) {
+            writeHeadToServerResponse(componentResponse, response);
+            if (response.statusCode >= 300 && response.statusCode < 400) {
+              // Redirect: mock status to bypass fetch opaque responses
+              response.statusCode = 299;
+              return response.end();
+            }
+          }
+
           // Tell React to start writing to the writer
           startWriting();
 
@@ -432,4 +450,23 @@ async function renderAppFromStringWithPrepass(
     : body;
 }
 
+export function writeHeadToServerResponse(
+  {customHead = {}}: ServerComponentResponse,
+  serverResponse: ServerResponse
+) {
+  if (customHead.headers) {
+    for (const [key, value] of Object.entries(customHead.headers)) {
+      serverResponse.setHeader(key, value);
+    }
+  }
+
+  if (customHead.statusText) {
+    serverResponse.statusMessage = customHead.statusText;
+  }
+
+  if (customHead.status) {
+    serverResponse.statusCode = customHead.status;
+  }
+}
+
 export default renderHydrogen;

packages/hydrogen/src/framework/Hydration/Cache.client.ts

@@ -35,10 +35,13 @@ function createFromFetch(fetchPromise: Promise<any>) {
         if (!response.ok) {
           throw new Error(`Hydration request failed: ${response.statusText}`);
         }
-        return response.text();
-      })
-      .then((payload) => {
-        return convertHydrationResponseToReactComponents(payload);
+
+        // Mocked status to bypass fetch opaque responses
+        if (response.status === 299) {
+          return {redirect: response.headers.get('location')};
+        }
+
+        return response.text().then(convertHydrationResponseToReactComponents);
       })
       .catch((e) => {
         console.error(e);

packages/hydrogen/src/framework/Hydration/ServerComponentResponse.server.ts

@@ -2,10 +2,18 @@ import {renderToString} from 'react-dom/server';
 import {CacheOptions} from '../../types';
 import {generateCacheControlHeader} from '../cache';
 
+type Head = {
+  status?: number;
+  statusText?: string;
+  headers?: Record<string, any>;
+};
+
 export class ServerComponentResponse extends Response {
   private wait = false;
   private cacheOptions?: CacheOptions;
 
+  public customHead: Head | undefined;
+
   /**
    * Allow custom body to be a string or a Promise.
    */
@@ -36,6 +44,26 @@ export class ServerComponentResponse extends Response {
     return generateCacheControlHeader(options);
   }
 
+  writeHead({status, statusText, headers}: Head = {}) {
+    this.customHead = this.customHead || {};
+
+    if (status) {
+      this.customHead.status = status;
+    }
+
+    if (statusText) {
+      this.customHead.statusText = statusText;
+    }
+
+    if (headers) {
+      this.customHead.headers = {...this.customHead.headers, ...headers};
+    }
+  }
+
+  redirect(status: number, location: string) {
+    this.writeHead({status, headers: {location}});
+  }
+
   /**
    * Send the response from a Server Component. Renders React components to string,
    * and returns `null` to make React happy.