fix: avoid unnecessary source map rewriting for files without directives (#20)

- Add hasDirective check in transform method to skip processing when no preprocessor directives are found
- This prevents unnecessary source map modifications that conflict with vite-plugin-vue-tracer
- Fixes Nuxt DevTools element selection functionality by preserving correct source maps
- Only processes files that actually contain #if, #define, #message, or other directives

Author: godgivemegift

src/core/context/index.ts

@@ -78,6 +78,9 @@ export class Context {
 
   transform(code: string, _id: string) {
     const tokens = Lexer.lex(code, this.lexers)
+    const hasDirective = tokens.some(token => token.type !== 'code')
+    if (!hasDirective)
+      return
     const ast = Parser.parse(tokens, this.parsers)
 
     const transformed = Transformer.transform(ast, this.transforms)