fix(rsc): avoid unnecessary server hmr due to tailwind module deps

Author: hi-ogawa

packages/plugin-rsc/examples/basic/src/routes/tailwind/unused.tsx

@@ -0,0 +1 @@
+console.log('unused file text-[#f12345]')

packages/plugin-rsc/src/plugin.ts

@@ -398,6 +398,16 @@ export default function vitePluginRsc(
 
         if (!isInsideClientBoundary(ctx.modules)) {
           if (this.environment.name === 'rsc') {
+            // detect if this module is only created as css deps (e.g. tailwind)
+            // (NOTE: this is not necessary since Vite 7.1.0-beta.0 https://github.com/vitejs/vite/pull/20391 )
+            if (
+              ctx.modules
+                .flatMap((m) => [...m.importers])
+                .every((m) => m.id && isCSSRequest(m.id))
+            ) {
+              return
+            }
+
             // transform js to surface syntax errors
             for (const mod of ctx.modules) {
               if (mod.type === 'js') {
@@ -426,6 +436,7 @@ export default function vitePluginRsc(
             // Server files can be included in client module graph, for example,
             // when `addWatchFile` is used to track js files as style dependency (e.g. tailwind)
             // In this case, reload all importers (for css hmr), and return empty modules to avoid full-reload.
+            // (NOTE: this is not necessary since Vite 7.1.0-beta.0 https://github.com/vitejs/vite/pull/20391 )
             const env = ctx.server.environments.rsc!
             const mod = env.moduleGraph.getModuleById(ctx.file)
             if (mod) {