fix: custom extensions work with the native compiler

.changeset/native-compiler-custom-extensions.md

@@ -0,0 +1,5 @@
+---
+'vite-plugin-solid': patch
+---
+
+Custom `extensions` work with the native compiler again. The native compiler picks its parser dialect from the file extension, so the transform builds a borrowed-extension filename (`foo.mdx` → `foo.mdx.jsx`, or `.tsx` when the extension is registered as TypeScript) for exactly this case — but only the lazy and refresh passes used it; the JSX transform itself still received the raw id, and `@dom-expressions/compiler` rejected it with "Unknown file extension" (#297). `compiler: 'babel'` was unaffected because that path names the parser plugins explicitly. The JSX transform now receives the same borrowed filename as the other native passes.

src/index.ts

@@ -1104,7 +1104,7 @@ export default function solidPlugin(options: Partial<Options> = {}): Plugin[] {
 
         const result = await compiler.transformAsync(code, {
           ...solidOptions,
-          filename: id,
+          filename: nativeFilename,
           sourceMap: true,
         });
         maps.push(result.map);