fix: keep Solid Start Cloudflare SSR on Web Streams

.changeset/quiet-cloudflare-streams.md

@@ -0,0 +1,6 @@
+---
+'@tanstack/router-core': patch
+'@tanstack/start-server-core': patch
+---
+
+Keep shared SSR stream transforms on Web Streams so Solid Start can use Cloudflare's narrow `nodejs_als` compatibility flag. Remove the unused Node pipeable adapter exports; React keeps its existing Node conversion at the renderer boundary.

e2e/solid-start/basic-cloudflare/src/routes/index.tsx

@@ -1,5 +1,6 @@
 import { createFileRoute } from '@tanstack/solid-router'
 import { createServerFn } from '@tanstack/solid-start'
+import { getRequestHeader } from '@tanstack/solid-start/server'
 import { env } from 'cloudflare:workers'
 
 export const Route = createFileRoute('/')({
@@ -11,6 +12,7 @@ const getData = createServerFn().handler(() => {
   return {
     message: `Running in ${navigator.userAgent}`,
     myVar: env.MY_VAR,
+    requestHeader: getRequestHeader('x-solid-start-context'),
   }
 })
 
@@ -22,6 +24,7 @@ function Home() {
       <h3>Welcome Home!!!</h3>
       <p data-testid="message">{data().message}</p>
       <p data-testid="myVar">{data().myVar}</p>
+      <p data-testid="requestHeader">{data().requestHeader}</p>
     </div>
   )
 }

e2e/solid-start/basic-cloudflare/tests/app.spec.ts

@@ -17,6 +17,16 @@ test('returns the correct value from a Cloudflare binding', async ({
   await expect(page.getByTestId('myVar')).toHaveText('Hello from Cloudflare')
 })
 
+test('preserves request context with nodejs_als', async ({ page }) => {
+  await page.setExtraHTTPHeaders({
+    'x-solid-start-context': 'request-context-works',
+  })
+  await page.goto('/')
+  await expect(page.getByTestId('requestHeader')).toHaveText(
+    'request-context-works',
+  )
+})
+
 test('prerender with Cloudflare Workers runtime', async ({ page }) => {
   // Verify the static page was prerendered during build
   const distDir = join(process.cwd(), 'dist', 'client')

e2e/solid-start/basic-cloudflare/worker-configuration.d.ts

@@ -1,18 +1,12 @@
 /* eslint-disable */
-// Generated by Wrangler by running `wrangler types` (hash: b11df627d8b3c51b1bf3230a546b0f20)
-// Runtime types generated with workerd@1.20260317.1 2025-09-24 nodejs_compat
+// Generated by Wrangler by running `wrangler types` (hash: 24a3fe972e2c4aaa57bb30eaba75ee7a)
+// Runtime types generated with workerd@1.20260317.1 2025-09-24 nodejs_als
 declare namespace Cloudflare {
 	interface Env {
 		MY_VAR: "Hello from Cloudflare";
 	}
 }
 interface Env extends Cloudflare.Env {}
-type StringifyValues<EnvType extends Record<string, unknown>> = {
-	[Binding in keyof EnvType]: EnvType[Binding] extends string ? EnvType[Binding] : string;
-};
-declare namespace NodeJS {
-	interface ProcessEnv extends StringifyValues<Pick<Cloudflare.Env, "MY_VAR">> {}
-}
 
 // Begin runtime types
 /*! *****************************************************************************

e2e/solid-start/basic-cloudflare/wrangler.jsonc

@@ -2,7 +2,7 @@
   "$schema": "node_modules/wrangler/config-schema.json",
   "name": "tanstack-start-app",
   "compatibility_date": "2025-09-24",
-  "compatibility_flags": ["nodejs_compat"],
+  "compatibility_flags": ["nodejs_als"],
   "main": "@tanstack/solid-start/server-entry",
   "vars": {
     "MY_VAR": "Hello from Cloudflare",

examples/solid/start-basic-cloudflare/worker-configuration.d.ts

@@ -1,18 +1,12 @@
 /* eslint-disable */
-// Generated by Wrangler by running `wrangler types` (hash: b11df627d8b3c51b1bf3230a546b0f20)
-// Runtime types generated with workerd@1.20260317.1 2025-09-24 nodejs_compat
+// Generated by Wrangler by running `wrangler types` (hash: 24a3fe972e2c4aaa57bb30eaba75ee7a)
+// Runtime types generated with workerd@1.20260317.1 2025-09-24 nodejs_als
 declare namespace Cloudflare {
 	interface Env {
 		MY_VAR: "Hello from Cloudflare";
 	}
 }
 interface Env extends Cloudflare.Env {}
-type StringifyValues<EnvType extends Record<string, unknown>> = {
-	[Binding in keyof EnvType]: EnvType[Binding] extends string ? EnvType[Binding] : string;
-};
-declare namespace NodeJS {
-	interface ProcessEnv extends StringifyValues<Pick<Cloudflare.Env, "MY_VAR">> {}
-}
 
 // Begin runtime types
 /*! *****************************************************************************

examples/solid/start-basic-cloudflare/wrangler.jsonc

@@ -2,7 +2,7 @@
   "$schema": "node_modules/wrangler/config-schema.json",
   "name": "tanstack-start-app",
   "compatibility_date": "2025-09-24",
-  "compatibility_flags": ["nodejs_compat"],
+  "compatibility_flags": ["nodejs_als"],
   "main": "@tanstack/solid-start/server-entry",
   "vars": {
     "MY_VAR": "Hello from Cloudflare",

packages/react-router/tests/renderRouterToStream.test.tsx

@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, test, vi } from 'vitest'
 import { attachRouterServerSsrUtils } from '@tanstack/router-core/ssr/server'
 import { createMemoryHistory, createRootRoute, createRouter } from '../src'
+import type { PassThrough } from 'node:stream'
 import type { RouterManagedTag } from '@tanstack/router-core'
 import type * as RouterSsrServer from '@tanstack/router-core/ssr/server'
 import type * as ReactDomServer from 'react-dom/server'
@@ -742,18 +743,26 @@ describe('renderRouterToStream - renderer selection and pipeable errors', () =>
     let options:
       | Parameters<typeof actualReactDomServer.renderToPipeableStream>[1]
       | undefined
+    let destination: PassThrough | undefined
     const abort = vi.fn((reason: unknown) => {
       options?.onError?.(reason, { componentStack: '' })
     })
     reactDomServerMocks.renderToPipeableStream.mockImplementationOnce(
       (_children, nextOptions) => {
         options = nextOptions
         queueMicrotask(() => nextOptions.onShellReady())
-        return { abort, pipe: vi.fn() }
+        return {
+          abort,
+          pipe: vi.fn((stream: PassThrough) => {
+            destination = stream
+            return stream
+          }),
+        }
       },
     )
 
     const router = await buildRouter()
+    const cleanup = vi.spyOn(router.serverSsr!, 'cleanup')
     const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {})
     const reason = new Error('pipeable-consumer-gone')
     try {
@@ -767,7 +776,9 @@ describe('renderRouterToStream - renderer selection and pipeable errors', () =>
       )
 
       await response.body!.cancel(reason)
-      expect(abort).toHaveBeenCalledWith(reason)
+      expect(abort).toHaveBeenCalledExactlyOnceWith(reason)
+      await vi.waitFor(() => expect(destination?.destroyed).toBe(true))
+      expect(cleanup).toHaveBeenCalledOnce()
       expect(errorSpy).not.toHaveBeenCalled()
     } finally {
       errorSpy.mockRestore()

packages/router-core/src/ssr/server.ts

@@ -17,7 +17,6 @@ export type {
   SsrResponse,
 } from './handlerCallback'
 export {
-  transformPipeableStreamWithRouter,
   transformHtmlStringWithRouter,
   transformReadableStreamWithRouter,
 } from './transformStreamWithRouter'

packages/router-core/src/ssr/transformStreamWithRouter.ts

@@ -1,4 +1,3 @@
-import { Readable } from 'node:stream'
 import {
   DOCUMENT_CLOSE_ANCHOR_INDEX,
   DOCUMENT_CLOSE_BYTES,
@@ -49,20 +48,6 @@ type AppStream =
   | ReadableStream<AppStreamValue>
   | NodeReadableStream<AppStreamValue>
 
-export function transformPipeableStreamWithRouter(
-  router: AnyRouter,
-  routerStream: Readable,
-  opts?: TransformStreamWithRouterOptions,
-) {
-  return Readable.fromWeb(
-    transformReadableStreamWithRouter(
-      router,
-      Readable.toWeb(routerStream) as AppStream,
-      opts,
-    ) as NodeReadableStream<Uint8Array>,
-  )
-}
-
 export async function transformHtmlStringWithRouter(
   router: AnyRouter,
   html: string,

packages/router-core/tests/transformStreamWithRouter.test.ts

@@ -21,17 +21,34 @@ import {
 import { attachRouterServerSsrUtils } from '../src/ssr/ssr-server'
 import {
   transformHtmlStringWithRouter,
-  transformPipeableStreamWithRouter,
   transformReadableStreamWithRouter,
 } from '../src/ssr/transformStreamWithRouter'
 import {
   DOCUMENT_CLOSE_BYTES,
   SCRIPT_CLOSE,
 } from '../src/ssr/htmlBoundaryScanner'
 import { createTestRouter } from './routerTestUtils'
+import type { TransformStreamWithRouterOptions } from '../src/ssr/transformStreamWithRouter'
+import type { AnyRouter } from '../src/router'
+import type { ReadableStream as NodeReadableStream } from 'node:stream/web'
 import type { RouterManagedTag } from '../src/manifest'
 import type { HydrationScriptOutput } from '../src/ssr/hydrationScripts'
 
+// Node interoperability belongs at the caller boundary, not in the shared SSR module.
+function transformPipeableStreamWithRouter(
+  router: AnyRouter,
+  stream: Readable,
+  opts?: TransformStreamWithRouterOptions,
+) {
+  return Readable.fromWeb(
+    transformReadableStreamWithRouter(
+      router,
+      Readable.toWeb(stream) as ReadableStream<Uint8Array | string>,
+      opts,
+    ) as NodeReadableStream<Uint8Array>,
+  )
+}
+
 const decoder = new TextDecoder()
 const DOCUMENT_CLOSE = decoder.decode(DOCUMENT_CLOSE_BYTES)
 const HYDRATION_SCRIPT_BOUNDARY_SUFFIX = decoder.decode(

packages/start-server-core/src/index.tsx

@@ -21,7 +21,6 @@ export {
   createRequestHandler,
   defineHandlerCallback,
   transformReadableStreamWithRouter,
-  transformPipeableStreamWithRouter,
 } from '@tanstack/router-core/ssr/server'
 export type { HandlerCallback } from '@tanstack/router-core/ssr/server'