Merge pull request #26837 from storybookjs/jeppe/24857-bug-mdx-compil…

…ation-breaks-when-using-vitejsplugin-react-swc-and-extending-its-plugins

Addon-docs: Fix MDX compilation when using `@vitejs/plugin-react-swc` with plugins
(cherry picked from commit d1b4753)

code/addons/docs/src/preset.ts

@@ -166,7 +166,8 @@ export const viteFinal = async (config: any, options: Options) => {
   // add alias plugin early to ensure any other plugins that also add the aliases will override this
   // eg. the preact vite plugin adds its own aliases
   plugins.unshift(packageDeduplicationPlugin);
-  plugins.push(mdxPlugin(options));
+  // mdx plugin needs to be before any react plugins
+  plugins.unshift(mdxPlugin(options));
 
   return config;
 };