Do not scan tailwind-merge sources for cadndidates

packages/@tailwindcss-vite/src/index.ts

@@ -9,6 +9,8 @@ import type { Plugin, ResolvedConfig, Rollup, Update, ViteDevServer } from 'vite
 const DEBUG = env.DEBUG
 const SPECIAL_QUERY_RE = /[?&](raw|url)\b/
 
+const IGNORED_DEPENDENCIES = ['tailwind-merge']
+
 export default function tailwindcss(): Plugin[] {
   let servers: ViteDevServer[] = []
   let config: ResolvedConfig | null = null
@@ -62,6 +64,18 @@ export default function tailwindcss(): Plugin[] {
   })
 
   function scanFile(id: string, content: string, extension: string, isSSR: boolean) {
+    for (let dependency of IGNORED_DEPENDENCIES) {
+      // We validated that Vite IDs always use posix style path separators, even on Windows.
+      // In dev build, Vite precompiles dependencies
+      if (id.includes(`.vite/deps/${dependency}.js`)) {
+        return
+      }
+      // In prod builds, use the node_modules path
+      if (id.includes(`/node_modules/${dependency}/`)) {
+        return
+      }
+    }
+
     let updated = false
     for (let candidate of moduleGraphScanner.scanFiles([{ content, extension }])) {
       updated = true

playgrounds/vite/package.json

@@ -13,6 +13,7 @@
     "@vitejs/plugin-react": "^4.3.4",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
+    "tailwind-merge": "^2.6.0",
     "tailwindcss": "workspace:^"
   },
   "devDependencies": {

playgrounds/vite/src/app.tsx

@@ -1,7 +1,9 @@
+import { twMerge } from 'tailwind-merge'
+
 export function App() {
   return (
     <div className="m-3 p-3 border">
-      <h1 className="text-blue-500">Hello World</h1>
+      <h1 className={twMerge('text-red-500', 'text-blue-500')}>Hello World</h1>
       <div className="-inset-x-full -inset-y-full -space-x-full -space-y-full -inset-full"></div>
     </div>
   )