fix(react-dom): use server.node.js for Deno to prevent build hangs (#35231)

[Garvitpant777]

When using react-dom/server in Deno (e.g. during SSR/pre-rendering with Vite, esbuild, Rollup, TanStack Start, etc.), the current conditional export maps the deno condition to server.browser.js.

That file creates a MessageChannel for task scheduling. In Deno, an open MessageChannel port prevents the process from exiting, causing bundlers to hang forever.

Fix

Change the Deno condition to use the Node.js server bundle instead:

-  "deno": "./server.browser.js",
+  "deno": "./server.node.js",

server.node.js uses setImmediate (fully supported and non-blocking in Deno) instead of MessageChannel, so the process exits cleanly.

Impact

Instantly fixes indefinite hangs for all Deno users performing SSR/pre-rendering builds
No behavioral change for Node, Bun, Edge, Workerd, or browser environments
No new bundle required – Deno already has excellent Node.js compatibility

Reproduction & Verification
Repository: https://github.com/Yovach/deno-tanstack-start-bug-reproduction
Before (official react-dom 19.2.0)
→ deno task build or npm run build hangs forever
After applying this one-line change
→ build completes successfully in ~2–3 seconds:

✔ 62 modules transformed.
...
✔ built in 2.90s

Closes #35231



<img width="546" height="273" alt="React_PR" src="https://github.com/user-attachments/assets/bb029b34-c2b6-4c31-9608-1d1127777caa" />

@acdlite @sebmarkbage @lunaruan @bvaughn @trueadm @eps1lon @fraidev @Yovach   Please check this out...


<img width="546" height="273" alt="React_PR" src="https://github.com/user-attachments/assets/2095bfba-5e71-4745-8a2d-45673d07ab45" />

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[Garvitpant777]

When using react-dom/server in Deno (e.g. during SSR/pre-rendering with Vite, esbuild, Rollup, TanStack Start, etc.), the current conditional export maps the deno condition to server.browser.js.

That file creates a MessageChannel for task scheduling. In Deno, an open MessageChannel port prevents the process from exiting, causing bundlers to hang forever.

Fix

Change the Deno condition to use the Node.js server bundle instead:

• "deno": "./server.browser.js",

• "deno": "./server.node.js",

server.node.js uses setImmediate (fully supported and non-blocking in Deno) instead of MessageChannel, so the process exits cleanly.

Impact

Instantly fixes indefinite hangs for all Deno users performing SSR/pre-rendering builds No behavioral change for Node, Bun, Edge, Workerd, or browser environments No new bundle required – Deno already has excellent Node.js compatibility

Reproduction & Verification Repository: https://github.com/Yovach/deno-tanstack-start-bug-reproduction Before (official react-dom 19.2.0) → deno task build or npm run build hangs forever After applying this one-line change → build completes successfully in ~2–3 seconds:

✔ 62 modules transformed. ... ✔ built in 2.90s

Closes #35231

@acdlite @sebmarkbage @lunaruan @bvaughn @trueadm @eps1lon @fraidev @Yovach Please check this out...

[Yovach]

When using react-dom/server in Deno (e.g. during SSR/pre-rendering with Vite, esbuild, Rollup, TanStack Start, etc.), the current conditional export maps the deno condition to server.browser.js.

That file creates a MessageChannel for task scheduling. In Deno, an open MessageChannel port prevents the process from exiting, causing bundlers to hang forever.

Fix

Change the Deno condition to use the Node.js server bundle instead:

* "deno": "./server.browser.js",


* "deno": "./server.node.js",

server.node.js uses setImmediate (fully supported and non-blocking in Deno) instead of MessageChannel, so the process exits cleanly.

Impact

Instantly fixes indefinite hangs for all Deno users performing SSR/pre-rendering builds No behavioral change for Node, Bun, Edge, Workerd, or browser environments No new bundle required – Deno already has excellent Node.js compatibility

Reproduction & Verification Repository: https://github.com/Yovach/deno-tanstack-start-bug-reproduction Before (official react-dom 19.2.0) → deno task build or npm run build hangs forever After applying this one-line change → build completes successfully in ~2–3 seconds:

✔ 62 modules transformed. ... ✔ built in 2.90s

Closes #35231

@acdlite @sebmarkbage @lunaruan @bvaughn @trueadm @eps1lon @fraidev @Yovach Please check this out...

Hi, a user already provided a PR here : https://github.com/facebook/react/pull/35235

[Garvitpant777]

When using react-dom/server in Deno (e.g. during SSR/pre-rendering with Vite, esbuild, Rollup, TanStack Start, etc.), the current conditional export maps the deno condition to server.browser.js. That file creates a MessageChannel for task scheduling. In Deno, an open MessageChannel port prevents the process from exiting, causing bundlers to hang forever.

Fix

Change the Deno condition to use the Node.js server bundle instead:

* "deno": "./server.browser.js",


* "deno": "./server.node.js",

server.node.js uses setImmediate (fully supported and non-blocking in Deno) instead of MessageChannel, so the process exits cleanly. Impact Instantly fixes indefinite hangs for all Deno users performing SSR/pre-rendering builds No behavioral change for Node, Bun, Edge, Workerd, or browser environments No new bundle required – Deno already has excellent Node.js compatibility Reproduction & Verification Repository: https://github.com/Yovach/deno-tanstack-start-bug-reproduction Before (official react-dom 19.2.0) → deno task build or npm run build hangs forever After applying this one-line change → build completes successfully in ~2–3 seconds: ✔ 62 modules transformed. ... ✔ built in 2.90s Closes #35231 @acdlite @sebmarkbage @lunaruan @bvaughn @trueadm @eps1lon @fraidev @Yovach Please check this out...

Hi, a user already provided a PR here : #35235

With due respect would you please merge my solution if it seems a good fit to you ... Thank You