feat(napi-derive): enhance the error messages in object validator (#2034)

crates/backend/src/codegen/struct.rs

@@ -511,10 +511,18 @@ impl NapiStruct {
             obj_field_setters.push(quote! { obj.set(#field_js_name, #alias_ident)?; });
           }
           if is_optional_field && !self.use_nullable {
-            obj_field_getters.push(quote! { let #alias_ident: #ty = obj.get(#field_js_name)?; });
+            obj_field_getters.push(quote! {
+              let #alias_ident: #ty = obj.get(#field_js_name).map_err(|mut err| {
+                err.reason = format!("{} on {}.{}", err.reason, #name_str, #field_js_name);
+                err
+              })?;
+            });
           } else {
             obj_field_getters.push(quote! {
-              let #alias_ident: #ty = obj.get(#field_js_name)?.ok_or_else(|| napi::bindgen_prelude::Error::new(
+              let #alias_ident: #ty = obj.get(#field_js_name).map_err(|mut err| {
+                err.reason = format!("{} on {}.{}", err.reason, #name_str, #field_js_name);
+                err
+              })?.ok_or_else(|| napi::bindgen_prelude::Error::new(
                 napi::bindgen_prelude::Status::InvalidArg,
                 format!("Missing field `{}`", #field_js_name),
               ))?;

examples/napi/__tests__/values.spec.ts

@@ -528,6 +528,18 @@ test('object', (t) => {
       rollup: '^4.0.0',
     },
   })
+  t.throws(
+    () =>
+      receiveAllOptionalObject({
+        // @ts-expect-error
+        name: 1,
+      }),
+    {
+      code: 'StringExpected',
+      message:
+        'Failed to convert JavaScript value `Number 1 ` into rust type `String` on AllOptionalObject.name',
+    },
+  )
 })
 
 test('get str from object', (t) => {
@@ -631,7 +643,7 @@ test('should throw if object type is not matched', (t) => {
   const err1 = t.throws(() => receiveStrictObject({ name: 1 }))
   t.is(
     err1?.message,
-    'Failed to convert JavaScript value `Number 1 ` into rust type `String`',
+    'Failed to convert JavaScript value `Number 1 ` into rust type `String` on StrictObject.name',
   )
   // @ts-expect-error
   const err2 = t.throws(() => receiveStrictObject({ bar: 1 }))