feat: works

__wasm/wit-bindgen-sample/container/src/main.rs

@@ -10,7 +10,10 @@ pub struct MyContainer;
 
 impl Container for MyContainer {
     fn fetch(&mut self, s: &str) -> String {
-        format!("FETCHED: {}", s)
+        // format!("FETCHED: {}", s)
+        let r = "{\"result\":\"{}\"}".into();
+        println!(">>>> {}", r);
+        r
     }
 }
 
@@ -25,9 +28,12 @@ fn main() -> Result<()> {
         |linker| container::add_to_linker(linker, |cx| -> &mut MyContainer { &mut cx.imports }),
         |store, module, linker| Exports::instantiate(store, module, linker, |cx| &mut cx.exports),
     )?;
-    let a = exports.eval_javascript(&mut store, "[script]");
+    let a = exports.eval_javascript(&mut store, "let a = [];fetch('aaa')");
 
-    println!("Hello, world! {:?}", a);
+    match a {
+        Ok(a) => println!("Hello, world! {:?}", a),
+        Err(e) => println!("ERROR: {}", e),
+    }
 
     Ok(())
 }