1 files changed, 48 insertions, 19 deletions

diff --git a/packages/integrations/react/src/index.ts b/packages/integrations/react/src/index.ts
index e0149e8e7..62803e788 100644
--- a/packages/integrations/react/src/index.ts
+++ b/packages/integrations/react/src/index.ts
@@ -12,15 +12,44 @@ export type ReactIntegrationOptions = Pick<
 
 const FAST_REFRESH_PREAMBLE = react.preambleCode;
 
-function getRenderer() {
+const versionsConfig = {
+	17: {
+		server: '@astrojs/react/server-v17.js',
+		client: '@astrojs/react/client-v17.js',
+		externals: ['react-dom/server.js', 'react-dom/client.js'],
+	},
+	18: {
+		server: '@astrojs/react/server.js',
+		client: '@astrojs/react/client.js',
+		externals: ['react-dom/server', 'react-dom/client']
+	},
+	19: {
+		server: '@astrojs/react/server.js',
+		client: '@astrojs/react/client.js',
+		externals: ['react-dom/server', 'react-dom/client']
+	}
+};
+
+type SupportedReactVersion = keyof (typeof versionsConfig);
+type ReactVersionConfig = (typeof versionsConfig)[SupportedReactVersion];
+
+function getReactMajorVersion(): number {
+	const matches = /\d+\./.exec(ReactVersion);
+	if(!matches) {
+		return NaN;
+	}
+	return Number(matches[0]);
+}
+
+function isUnsupportedVersion(majorVersion: number) {
+	return majorVersion < 17 || majorVersion > 19 || Number.isNaN(majorVersion);
+}
+
+function getRenderer(reactConfig: ReactVersionConfig) {
 	return {
 		name: '@astrojs/react',
-		clientEntrypoint: ReactVersion.startsWith('18.')
-			? '@astrojs/react/client.js'
-			: '@astrojs/react/client-v17.js',
-		serverEntrypoint: ReactVersion.startsWith('18.')
-			? '@astrojs/react/server.js'
-			: '@astrojs/react/server-v17.js',
+		clientEntrypoint: reactConfig.client,
+		serverEntrypoint: reactConfig.server,
 	};
 }
 
@@ -51,22 +80,18 @@ function getViteConfiguration({
 	exclude,
 	babel,
 	experimentalReactChildren,
-}: ReactIntegrationOptions = {}) {
+}: ReactIntegrationOptions = {}, reactConfig: ReactVersionConfig) {
 	return {
 		optimizeDeps: {
 			include: [
-				ReactVersion.startsWith('18.')
-					? '@astrojs/react/client.js'
-					: '@astrojs/react/client-v17.js',
+				reactConfig.client,
 				'react',
 				'react/jsx-runtime',
 				'react/jsx-dev-runtime',
 				'react-dom',
 			],
 			exclude: [
-				ReactVersion.startsWith('18.')
-					? '@astrojs/react/server.js'
-					: '@astrojs/react/server-v17.js',
+				reactConfig.server,
 			],
 		},
 		plugins: [react({ include, exclude, babel }), optionsPlugin(!!experimentalReactChildren)],
@@ -74,9 +99,7 @@ function getViteConfiguration({
 			dedupe: ['react', 'react-dom', 'react-dom/server'],
 		},
 		ssr: {
-			external: ReactVersion.startsWith('18.')
-				? ['react-dom/server', 'react-dom/client']
-				: ['react-dom/server.js', 'react-dom/client.js'],
+			external: reactConfig.externals,
 			noExternal: [
 				// These are all needed to get mui to work.
 				'@mui/material',
@@ -95,13 +118,19 @@ export default function ({
 	babel,
 	experimentalReactChildren,
 }: ReactIntegrationOptions = {}): AstroIntegration {
+	const majorVersion = getReactMajorVersion();
+	if(isUnsupportedVersion(majorVersion)) {
+		throw new Error(`Unsupported React version: ${majorVersion}.`);
+	}
+	const versionConfig = versionsConfig[majorVersion as SupportedReactVersion];
+
 	return {
 		name: '@astrojs/react',
 		hooks: {
 			'astro:config:setup': ({ command, addRenderer, updateConfig, injectScript }) => {
-				addRenderer(getRenderer());
+				addRenderer(getRenderer(versionConfig));
 				updateConfig({
-					vite: getViteConfiguration({ include, exclude, babel, experimentalReactChildren }),
+					vite: getViteConfiguration({ include, exclude, babel, experimentalReactChildren }, versionConfig),
 				});
 				if (command === 'dev') {
 					const preamble = FAST_REFRESH_PREAMBLE.replace(`__BASE__`, '/');