Properly initialize NODE_ENV if not already set (#12578)

* Properly initialize node env for react-router cli

* Properly initialize `NODE_ENV` in `react-router-serve`

---------

Co-authored-by: jrestall <james.restall@gmail.com>

Author: brophdawg11

.changeset/selfish-pianos-grab.md

@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+Properly initialize `NODE_ENV` if not already set for compatibility with React 19

contributors.yml

@@ -147,6 +147,7 @@
 - johnpangalos
 - jonkoops
 - jrakotoharisoa
+- jrestall
 - juanpprieto
 - jungwoo3490
 - kachun333

packages/react-router-dev/bin.js

@@ -1,2 +1,15 @@
 #!/usr/bin/env node
+let arg = require("arg");
+
+// Minimal replication of our actual parsing in `run.ts`.  If not already set,
+// default `NODE_ENV` so React loads the proper version in it's CJS entry script.
+// We have to do this before importing `run.ts` since that is what imports
+// `react` (indirectly via `react-router`)
+let args = arg({}, { argv: process.argv.slice(2) });
+if (args._[0] === "dev") {
+  process.env.NODE_ENV = process.env.NODE_ENV ?? "development";
+} else {
+  process.env.NODE_ENV = process.env.NODE_ENV ?? "production";
+}
+
 require("./dist/cli/index");

packages/react-router-serve/bin.js

@@ -1,2 +1,7 @@
 #!/usr/bin/env node
+
+// If not already set, default `NODE_ENV=production` so React loads the proper
+// version in it's CJS entry script
+process.env.NODE_ENV = process.env.NODE_ENV ?? "production";
+
 require("./dist/cli");