refactor: simplify generate source map

package.json

@@ -84,7 +84,7 @@
     "@babel/parser": "^7.24.5",
     "@rollup/pluginutils": "^5.1.0",
     "ast-kit": "^0.12.1",
-    "magic-string-ast": "^0.5.0",
+    "magic-string-ast": "^0.6.0",
     "unplugin": "^1.10.1"
   },
   "devDependencies": {

src/core/transform.ts

@@ -1,4 +1,8 @@
-import { MagicStringAST, type SourceMap } from 'magic-string-ast'
+import {
+  MagicStringAST,
+  type SourceMap,
+  generateTransform,
+} from 'magic-string-ast'
 import generate from '@babel/generator'
 import { babelParse, getLang, walkASTAsync } from 'ast-kit'
 import { useNodeRef } from './utils'
@@ -87,15 +91,6 @@ export async function transform(
       }
     }
   }
-  if (!s.hasChanged()) return undefined
 
-  return {
-    code: s.toString(),
-    get map() {
-      return s.generateMap({
-        source: id,
-        includeContent: true,
-      })
-    },
-  }
+  return generateTransform(s, id)
 }

src/core/utils.ts

@@ -4,7 +4,7 @@ import type { NodeRef } from './types'
 export function useNodeRef() {
   const nodeRefs: Map<Node, NodeRef<Node | undefined>> = new Map()
 
-  const getNodeRef = (node: Node) => {
+  function getNodeRef(node: Node) {
     if (nodeRefs.has(node)) return nodeRefs.get(node)!
     const ref: NodeRef<Node | undefined> = {
       value: node,