Switch Pro renderer client to async-http

CHANGELOG.md

@@ -24,6 +24,10 @@ After a release, run `/update-changelog` in Claude Code to analyze commits, writ
 
 ### [Unreleased]
 
+#### Breaking Changes
+
+- **[Pro]** **Node renderer HTTP client now uses async-http and requires Ruby 3.3+**: React on Rails Pro replaces the HTTPX-based renderer client with an `async-http` adapter for render, streaming, and asset-upload requests. Apps using React on Rails Pro must run Ruby 3.3 or newer before upgrading. The adapter scopes HTTP clients to individual renderer requests, so it does not reuse TCP connections between Rails requests; high-latency networks or very high request rates can see extra connection and HTTP/2 handshake overhead compared with HTTPX until persistent async-http clients are added in [Issue 3283](https://github.com/shakacode/react_on_rails/issues/3283). `config.renderer_http_pool_size` now limits concurrent streams on the request-scoped client instead of sizing a persistent process-wide connection pool, and HTTPX's implicit single transport retry is no longer present for renderer connection drops. [PR 3279](https://github.com/shakacode/react_on_rails/pull/3279) by [justin808](https://github.com/justin808).
+
 #### Added
 
 - **`react-on-rails/webpackHelpers` subpath export with `reactDomClientWarning`**: New webpack helper export so React 16/17 consumers can suppress the harmless `Module not found: Can't resolve 'react-dom/client'` warning with a one-liner instead of remembering a regex. The require inside `reactApis` is guarded by a runtime React-version check, so this warning never reflects a real failure, but webpack still emits it at build time because the static `require('react-dom/client')` cannot be tree-shaken without breaking React 18+. Pass `reactDomClientWarning` to `ignoreWarnings` (Webpack 5 / Shakapacker) or `stats.warningsFilter` (Webpack 4 / Webpacker 5). Fixes [Issue 3137](https://github.com/shakacode/react_on_rails/issues/3137).
@@ -64,6 +68,7 @@ After a release, run `/update-changelog` in Claude Code to analyze commits, writ
 - **[Pro]** **Pro migration generator rewrites all base-package references and preserves Gemfile pins**: `rails generate react_on_rails:pro` now rewrites Jest/Vitest mock helpers (`jest.mock`, `vi.mock`, `requireActual`/`importActual`, and the rest) and TypeScript `declare module 'react-on-rails'` blocks alongside its existing `import`/`require`/dynamic-import handling, and the Gemfile swap now preserves the user's existing version pin (and other gem options) instead of overwriting them with the running gem's version. `react_on_rails:doctor` is widened to match: it also flags stale side-effect imports (`import 'react-on-rails';`), Jest/Vitest mock helpers, and `declare module` blocks, and the new side-effect-import pattern keeps the doctor a superset of the rewriter so anything the rewriter doesn't reach gets surfaced. Closes [Issue 3104](https://github.com/shakacode/react_on_rails/issues/3104). [PR 3232](https://github.com/shakacode/react_on_rails/pull/3232) by [justin808](https://github.com/justin808).
 - **[Pro]** **Pro migration scans TypeScript 4.7 `.mts` and `.cts` modules**: `react_on_rails:doctor` and the Pro migration rewriter now include `.mts`/`.cts` source files (and their `.d.mts`/`.d.cts` declaration counterparts) when looking for stale `react-on-rails` references, matching the existing `.mjs`/`.cjs` coverage. Fixes [Issue 3250](https://github.com/shakacode/react_on_rails/issues/3250). [PR 3334](https://github.com/shakacode/react_on_rails/pull/3334) by [justin808](https://github.com/justin808).
 - **Doctor now honors nested JavaScript package roots**: `react_on_rails:doctor` now checks package-manager lockfiles, `package.json`, and installed React from the configured `node_modules_location`, reducing false diagnostics for legacy apps that keep dependencies under `client/`. The Vite migration guide now documents the supported thin-wrapper pattern for those layouts. Note: a missing `package.json` at the configured `node_modules_location` now emits a warning instead of being silently skipped, so apps misconfigured against a nonexistent path will see new diagnostics on upgrade. Fixes [Issue 3205](https://github.com/shakacode/react_on_rails/issues/3205). [PR 3220](https://github.com/shakacode/react_on_rails/pull/3220) by [justin808](https://github.com/justin808).
+- **[Pro]** **Streaming response chunks no longer duplicate leading-newline buffers**: Fixed `StreamRequest` line splitting so chunks that begin with `\n` yield an empty line instead of re-yielding the full buffered line. [PR 3279](https://github.com/shakacode/react_on_rails/pull/3279) by [justin808](https://github.com/justin808).
 - **Generated pack regeneration is now serialized**: `generate_packs_if_stale` now uses a Rails `tmp/` lock file, re-checks staleness after waiting, and avoids concurrent cleanup/regeneration races when multiple processes trigger auto-bundling at the same time. Fixes [Issue 1627](https://github.com/shakacode/react_on_rails/issues/1627). [PR 3231](https://github.com/shakacode/react_on_rails/pull/3231) by [justin808](https://github.com/justin808).
 - **Install generator validates the selected JavaScript package manager**: The install generator now checks the manager selected from `REACT_ON_RAILS_PACKAGE_MANAGER`, the `packageManager` field in `package.json`, or a lockfile on disk — instead of passing when any JavaScript package manager is installed. When the selected command is missing, the error names the selected manager, the source that selected it, and the available alternatives. The generator also warns when `REACT_ON_RAILS_PACKAGE_MANAGER` is set to a value outside the supported set (`npm`, `pnpm`, `yarn`, `bun`). Addresses package manager validation from [Issue 1958](https://github.com/shakacode/react_on_rails/issues/1958). [PR 3229](https://github.com/shakacode/react_on_rails/pull/3229) by [justin808](https://github.com/justin808).
 - **Server-render error wrapping preserves original causes**: When server rendering catches a non-`Error` thrown value, React on Rails now wraps it with the original value attached as `cause`, making downstream debugging preserve more context. Fixes [Issue 1746](https://github.com/shakacode/react_on_rails/issues/1746). [PR 3230](https://github.com/shakacode/react_on_rails/pull/3230) by [justin808](https://github.com/justin808).

docs/oss/configuration/configuration-pro.md

@@ -82,7 +82,9 @@ ReactOnRailsPro.configure do |config|
   # config.renderer_password = ENV["RENDERER_PASSWORD"]
 
   # Set the `ssr_timeout` configuration so the Rails server will not wait more than this many seconds
-  # for a SSR request to return once issued.
+  # for a SSR request to return once issued. With the async-http renderer client, this bounds the
+  # entire renderer request, including streaming responses. Increase this value for long-running
+  # streaming SSR responses.
   config.ssr_timeout = 5
 
   # If false, then crash if no backup rendering when the remote renderer is not available
@@ -92,19 +94,23 @@ ReactOnRailsPro.configure do |config|
   # Default for `renderer_use_fallback_exec_js` is true.
   config.renderer_use_fallback_exec_js = false
 
-  # The maximum size of the http connection pool,
-  # Set +pool_size+ to limit the maximum number of connections allowed.
-  # Defaults to 1/4 the number of allowed file handles.  You can have no more
-  # than this many threads with active HTTP transactions.
+  # With the async-http renderer client, clients are scoped to individual requests.
+  # For the HTTP/2 renderer connection, this limits concurrent streams on that request's client
+  # rather than the size of a persistent process-wide connection pool. The current adapter does
+  # not reuse TCP connections between Rails requests, so high-latency networks or very high
+  # request rates can see extra connection and HTTP/2 handshake overhead compared with HTTPX.
+  # Setting this value emits a warning so upgrades notice the changed semantics.
+  # Setting this to nil keeps the default limit; it does not make the async-http client unlimited.
   # Default for `renderer_http_pool_size` is 10
   config.renderer_http_pool_size = 10
 
-  # Seconds to wait for an available connection before a timeout error is raised
+  # TCP connect timeout in seconds. After the socket connects, request processing and streaming
+  # are bounded by `ssr_timeout`.
   # Default for `renderer_http_pool_timeout` is 5
   config.renderer_http_pool_timeout = 5
 
-  # warn_timeout  - Displays an error message if a request takes longer than the given time in seconds
-  # (used to give hints to increase the pool size). Default is 0.25
+  # warn_timeout  - Displays an error message if a request takes longer than the given time in seconds.
+  # Default is 0.25
   config.renderer_http_pool_warn_timeout = 0.25 # seconds
 
   # Snippet of JavaScript to be run right at the beginning of the server rendering process. The code

docs/pro/updating.md

@@ -379,6 +379,39 @@ If you only use ExecJS for SSR (the default), you do not need `react-on-rails-pr
 
 ### Additional Upgrade Notes
 
+#### Upgrading to a version with the async-http node renderer client
+
+React on Rails Pro now uses `async-http` instead of HTTPX for Rails-to-node-renderer requests.
+This affects render, streaming render, and asset upload requests.
+
+Before upgrading:
+
+- Run Ruby 3.3 or newer. The `async-http` dependency requires Ruby 3.3+.
+- Keep the transitive `io-endpoint` gem in the 0.17.x range when updating `async-http`. Do not run
+  `bundle update async-http` without checking that `io-endpoint` remains compatible; the Pro client fails fast at boot
+  if `IO::Endpoint::Wrapper` internals change in a later `io-endpoint` release.
+- Remove direct application assumptions about HTTPX-specific response or error classes in Pro renderer request paths.
+- Keep `config.ssr_timeout` sized for the full renderer request. With the async-http client, this timeout bounds
+  connect, request write, and response streaming time.
+- Treat `config.renderer_http_pool_timeout` as the TCP connect timeout. After the socket connects, renderer work is
+  still bounded by `ssr_timeout`.
+- Treat `config.renderer_http_pool_size` as a per-request HTTP/2 stream limit, not as a persistent process-wide
+  connection pool size. The current async-http adapter opens a request-scoped client for each renderer request and
+  does not reuse TCP connections between Rails requests, so high-latency networks or very high request rates can see
+  extra connection and HTTP/2 handshake overhead compared with HTTPX. Setting this value now emits a warning to make
+  the changed meaning visible during upgrades. Setting it to `nil` keeps the default stream limit; it does not make
+  the request-scoped async-http client unlimited. Persistent async-http connection reuse is tracked in
+  [Issue 3283](https://github.com/shakacode/react_on_rails/issues/3283).
+- Expect renderer connection drops to surface immediately as `ReactOnRailsPro::Error`/connection failures. HTTPX
+  previously performed one implicit transport retry for some connection drops; the async-http adapter uses
+  `retries: 0` and leaves retry policy to the existing bundle-upload retry loop and caller behavior.
+- Run the node renderer client from the normal synchronous Rails request path. Async Rails servers or middleware that
+  call the renderer from inside an existing Async reactor without an `Async::Task.current?` context are not currently
+  supported because the sync fallback may create a nested reactor. Keep Falcon/async-rails deployments on the previous
+  HTTPX renderer client until this support is explicitly added.
+- `config.renderer_http_keep_alive_timeout` remains accepted for compatibility, but it has no effect because
+  async-http clients are currently scoped to individual requests. Setting it now emits a deprecation warning.
+
 #### Upgrading to 16.4.0 or later
 
 ##### JWT gem requirement

react_on_rails_pro/Gemfile.lock

@@ -23,10 +23,9 @@ PATH
     react_on_rails_pro (16.7.0.rc.0)
       addressable
       async (>= 2.29)
-      connection_pool
+      async-http (~> 0.95)
       execjs (~> 2.9)
-      http-2 (>= 1.1.1)
-      httpx (~> 1.5)
+      io-endpoint (~> 0.17.0)
       jwt (>= 2.7)
       rainbow
       react_on_rails (= 16.7.0.rc.0)
@@ -117,6 +116,19 @@ GEM
       io-event (~> 1.11)
       metrics (~> 0.12)
       traces (~> 0.18)
+    async-http (0.95.1)
+      async (>= 2.10.2)
+      async-pool (~> 0.11)
+      io-endpoint (~> 0.14)
+      io-stream (~> 0.6)
+      metrics (~> 0.12)
+      protocol-http (~> 0.62)
+      protocol-http1 (~> 0.39)
+      protocol-http2 (~> 0.26)
+      protocol-url (~> 0.2)
+      traces (~> 0.10)
+    async-pool (0.11.2)
+      async (>= 2.0)
     base64 (0.3.0)
     benchmark (0.5.0)
     bigdecimal (4.0.1)
@@ -181,13 +193,12 @@ GEM
     graphiql-rails (1.10.0)
       railties
     hashdiff (1.1.0)
-    http-2 (1.1.1)
-    httpx (1.7.0)
-      http-2 (>= 1.0.0)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     io-console (0.8.2)
+    io-endpoint (0.17.2)
     io-event (1.14.2)
+    io-stream (0.13.0)
     irb (1.17.0)
       pp (>= 0.6.0)
       prism (>= 1.3.0)
@@ -258,6 +269,14 @@ GEM
       prettyprint
     prettyprint (0.2.0)
     prism (1.9.0)
+    protocol-hpack (1.5.1)
+    protocol-http (0.62.2)
+    protocol-http1 (0.39.0)
+      protocol-http (~> 0.62)
+    protocol-http2 (0.26.0)
+      protocol-hpack (~> 1.4)
+      protocol-http (~> 0.62)
+    protocol-url (0.4.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)

react_on_rails_pro/README.md

@@ -257,7 +257,7 @@ end
 
 ### Prerequisites
 
-- **Ruby**: >= 3.0
+- **Ruby**: >= 3.3
 - **Rails**: >= 6.0 (recommended: 7.0+)
 - **React on Rails**: >= 11.0.7 (recommended: latest)
 - **Node.js**: >= 18 (for Node Renderer)
@@ -267,7 +267,7 @@ end
 
 | React on Rails Pro | React on Rails | Rails  | Ruby   | React   |
 | ------------------ | -------------- | ------ | ------ | ------- |
-| 16.x               | >= 16.0        | >= 7.0 | >= 3.2 | >= 18   |
+| 16.x               | >= 16.0        | >= 7.0 | >= 3.3 | >= 18   |
 | 3.x                | >= 13.0        | >= 6.0 | >= 3.0 | >= 16.8 |
 
 > **Note:** Pro version numbers were aligned with the core gem starting at 16.2.0. Pro 16.x is the direct successor to Pro 3.x/4.x.

react_on_rails_pro/lib/react_on_rails_pro.rb

@@ -3,9 +3,6 @@
 require "rails"
 require "react_on_rails"
 
-# Apply HTTPX bug fix for stream_bidi plugin
-require "react_on_rails_pro/httpx_stream_bidi_patch"
-
 require "react_on_rails_pro/request"
 require "react_on_rails_pro/version"
 require "react_on_rails_pro/constants"