Support loading plugins and configs

Author: thecrypticace

packages/tailwindcss-language-server/src/util/v4/design-system.ts

@@ -2,6 +2,7 @@ import type { DesignSystem } from '@tailwindcss/language-service/src/util/v4'
 
 import postcss from 'postcss'
 import { resolveCssImports } from '../../css'
+import { resolveFrom } from '../resolveFrom'
 
 const HAS_V4_IMPORT = /@import\s*(?:'tailwindcss'|"tailwindcss")/
 const HAS_V4_THEME = /@theme\s*\{/
@@ -38,8 +39,16 @@ export async function loadDesignSystem(
 
   // Step 3: Take the resolved CSS and pass it to v4's `loadDesignSystem`
   let design: DesignSystem = await tailwindcss.__unstable__loadDesignSystem(resolved.css, {
-    loadPlugin() {
-      return () => {}
+    async loadPlugin(id: string) {
+      let resolvedPath = resolveFrom(filepath, id)
+
+      return import(resolvedPath).then((m) => m.default ?? m)
+    },
+
+    async loadConfig(id: string) {
+      let resolvedPath = resolveFrom(filepath, id)
+
+      return import(resolvedPath).then((m) => m.default ?? m)
     },
   })