Upgrade to react 19 (#428)

.changeset/beige-waves-begin.md

@@ -0,0 +1,5 @@
+---
+"webpack-config-single-spa-react": major
+---
+
+Add react-dom/client to externals

.changeset/forty-bats-talk.md

@@ -0,0 +1,5 @@
+---
+"generator-single-spa": major
+---
+
+Upgrade to single-spa-react@6 and react@19

packages/generator-single-spa/src/react/templates/react.package.json

@@ -43,8 +43,8 @@
     "webpack-merge": "^5.8.0"
   },
   "dependencies": {
-    "react": "^17.0.2",
-    "react-dom": "^17.0.2",
-    "single-spa-react": "^4.3.1"
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
+    "single-spa-react": "^6.0.2"
   }
 }

packages/generator-single-spa/src/react/templates/src/main.js

@@ -1,11 +1,13 @@
 import React from "react";
 import ReactDOM from "react-dom";
+import ReactDOMClient from "react-dom/client";
 import singleSpaReact from "single-spa-react";
 import Root from "./root.component";
 
 const lifecycles = singleSpaReact({
   React,
   ReactDOM,
+  ReactDOMClient,
   rootComponent: Root,
   errorBoundary(err, info, props) {
     // Customize the root error boundary for your microfrontend here.

packages/webpack-config-single-spa-react/lib/webpack-config-single-spa-react.js

@@ -9,7 +9,7 @@ function webpackConfigSingleSpaReact(opts) {
   const config = webpackConfigSingleSpa(opts);
 
   if (!webpackConfigEnv.standalone) {
-    config.externals.push("react", "react-dom");
+    config.externals.push("react", "react-dom", "react-dom/client");
   }
 
   return config;