fix: external redirects (fix #1103)

Author: brillout

test/abort-v1/pages/redirect-external/+Page.tsx

@@ -0,0 +1,7 @@
+export default Page
+
+import React from 'react'
+
+function Page() {
+  return <p>I will never be shown because of throw redirect() in the guard() hook.</p>
+}

test/abort-v1/pages/redirect-external/+guard.ts

@@ -0,0 +1,7 @@
+export default guard
+
+import { redirect } from 'vite-plugin-ssr/abort'
+
+async function guard() {
+  throw redirect('https://vite-plugin-ssr.com')
+}

test/abort-v1/renderer/PageLayout.tsx

@@ -17,6 +17,7 @@ function PageLayout({ children, pageContext }: { children: React.ReactNode; page
             <Nav href="/render-homepage" />
             <Nav href="/show-error-page" />
             <Nav href="/permanent-redirect" />
+            <Nav href="/redirect-external" />
           </Sidebar>
           <Content>{children}</Content>
         </Layout>

test/abort-v1/test.ts

@@ -1,7 +1,13 @@
 export { testRun as test }
 
 import { run, page, test, expect, getServerUrl, fetchHtml, autoRetry, expectLog, partRegex } from '@brillout/test-e2e'
-import { ensureWasClientSideRouted, expectUrl, hydrationDone, testCounter, expectPageContextJsonRequest } from '../utils'
+import {
+  ensureWasClientSideRouted,
+  expectUrl,
+  hydrationDone,
+  testCounter,
+  expectPageContextJsonRequest
+} from '../utils'
 
 function testRun(cmd: string, pageContextInitHasClientData = false) {
   run(cmd)
@@ -108,4 +114,10 @@ function testRun(cmd: string, pageContextInitHasClientData = false) {
     await page.click('a[href="/permanent-redirect"]')
     expectUrl('/')
   })
+
+  test('external redirect', async () => {
+    await page.goto(getServerUrl() + '/')
+    await page.click('a[href="/redirect-external"]')
+    await page.waitForURL('https://vite-plugin-ssr.com')
+  })
 }

vite-plugin-ssr/node/runtime/renderPage/createHttpResponseObject/assertNoInfiniteHttpRedirect.ts

@@ -9,6 +9,15 @@ const globalObject = getGlobalObject<{ redirectGraph: Graph }>('assertNoInfinite
 })
 
 function assertNoInfiniteHttpRedirect(urlRedirectOriginal: string, urlRedirectPathnameLogical: string) {
+  if (urlRedirectOriginal.startsWith('http')) {
+    // We assume that the redirect points to an external origin, and we can therefore assume that the app doesn't define an infinite loop (in itself).
+    //  - There isn't a reliable way to check whether the redirect points to an external origin or the same origin: the user usually passes the URL without origin.
+    //    ```js
+    //    // URL origin is usually missing
+    //    renderPage({ urlOriginal: '/some/pathname' })
+    //    ```
+    return
+  }
   assert(urlRedirectOriginal.startsWith('/'))
   assert(urlRedirectPathnameLogical.startsWith('/'))
   const graph = copy(globalObject.redirectGraph)