feat(napi-derive): allow partial implement From/To Napivalue for Object (#1448)

crates/backend/src/ast.rs

@@ -80,6 +80,8 @@ pub struct NapiStruct {
   pub fields: Vec<NapiStructField>,
   pub is_tuple: bool,
   pub kind: NapiStructKind,
+  pub object_from_js: bool,
+  pub object_to_js: bool,
   pub js_mod: Option<String>,
   pub comments: Vec<String>,
   pub implement_iterator: bool,

crates/backend/src/codegen/struct.rs

@@ -558,6 +558,46 @@ impl NapiStruct {
       }
     };
 
+    let to_napi_value = if self.object_to_js {
+      quote! {
+        impl napi::bindgen_prelude::ToNapiValue for #name {
+          unsafe fn to_napi_value(env: napi::bindgen_prelude::sys::napi_env, val: #name) -> napi::bindgen_prelude::Result<napi::bindgen_prelude::sys::napi_value> {
+            let env_wrapper = napi::bindgen_prelude::Env::from(env);
+            let mut obj = env_wrapper.create_object()?;
+
+            let #destructed_fields = val;
+            #(#obj_field_setters)*
+
+            napi::bindgen_prelude::Object::to_napi_value(env, obj)
+          }
+        }
+      }
+    } else {
+      quote! {}
+    };
+
+    let from_napi_value = if self.object_from_js {
+      quote! {
+        impl napi::bindgen_prelude::FromNapiValue for #name {
+          unsafe fn from_napi_value(
+            env: napi::bindgen_prelude::sys::napi_env,
+            napi_val: napi::bindgen_prelude::sys::napi_value
+          ) -> napi::bindgen_prelude::Result<Self> {
+            let env_wrapper = napi::bindgen_prelude::Env::from(env);
+            let mut obj = napi::bindgen_prelude::Object::from_napi_value(env, napi_val)?;
+
+            #(#obj_field_getters)*
+
+            let val = #destructed_fields;
+
+            Ok(val)
+          }
+        }
+      }
+    } else {
+      quote! {}
+    };
+
     quote! {
       impl napi::bindgen_prelude::TypeName for #name {
         fn type_name() -> &'static str {
@@ -569,33 +609,9 @@ impl NapiStruct {
         }
       }
 
-      impl napi::bindgen_prelude::ToNapiValue for #name {
+      #to_napi_value
-        unsafe fn to_napi_value(env: napi::bindgen_prelude::sys::napi_env, val: #name) -> napi::bindgen_prelude::Result<napi::bindgen_prelude::sys::napi_value> {
-          let env_wrapper = napi::bindgen_prelude::Env::from(env);
-          let mut obj = env_wrapper.create_object()?;
 
-          let #destructed_fields = val;
+      #from_napi_value
-          #(#obj_field_setters)*
-
-          napi::bindgen_prelude::Object::to_napi_value(env, obj)
-        }
-      }
-
-      impl napi::bindgen_prelude::FromNapiValue for #name {
-        unsafe fn from_napi_value(
-          env: napi::bindgen_prelude::sys::napi_env,
-          napi_val: napi::bindgen_prelude::sys::napi_value
-        ) -> napi::bindgen_prelude::Result<Self> {
-          let env_wrapper = napi::bindgen_prelude::Env::from(env);
-          let mut obj = napi::bindgen_prelude::Object::from_napi_value(env, napi_val)?;
-
-          #(#obj_field_getters)*
-
-          let val = #destructed_fields;
-
-          Ok(val)
-        }
-      }
 
       impl napi::bindgen_prelude::ValidateNapiValue for #name {}
     }

crates/macro/src/parser/attrs.rs

@@ -56,6 +56,8 @@ macro_rules! attrgen {
       (strict, Strict(Span)),
       (return_if_invalid, ReturnIfInvalid(Span)),
       (object, Object(Span)),
+      (object_from_js, ObjectFromJs(Span, Option<bool>)),
+      (object_to_js, ObjectToJs(Span, Option<bool>)),
       (custom_finalize, CustomFinalize(Span)),
       (namespace, Namespace(Span, String, Span)),
       (iterator, Iterator(Span)),

crates/macro/src/parser/mod.rs

@@ -995,6 +995,8 @@ impl ConvertToAST for syn::ItemStruct {
         fields,
         is_tuple,
         kind: struct_kind,
+        object_from_js: opts.object_from_js(),
+        object_to_js: opts.object_to_js(),
         js_mod: namespace,
         comments: extract_doc_comments(&self.attrs),
         implement_iterator,

examples/napi/__test__/typegen.spec.ts.md

@@ -172,6 +172,11 @@ Generated by [AVA](https://avajs.dev).
     }␊
     export function createObjWithProperty(): { value: ArrayBuffer, get getter(): number }␊
     export function getterFromObj(): number␊
+    export interface ObjectOnlyFromJs {␊
+      count: number␊
+      callback: (err: Error | null, value: number) => any␊
+    }␊
+    export function receiveObjectOnlyFromJs(obj: { count: number, callback: (err: Error | null, count: number) => void }): void␊
     export function asyncPlus100(p: Promise<number>): Promise<number>␊
     /** This is an interface for package.json */␊
     export interface PackageJson {␊

examples/napi/__test__/values.spec.ts

@@ -89,6 +89,7 @@ import {
   returnJsFunction,
   testSerdeRoundtrip,
   createObjWithProperty,
+  receiveObjectOnlyFromJs,
   dateToNumber,
   chronoDateToMillis,
   derefUint8Array,
@@ -816,6 +817,22 @@ Napi4Test('accept ThreadsafeFunction Fatal', async (t) => {
   })
 })
 
+Napi4Test('object only from js', (t) => {
+  return new Promise((resolve, reject) => {
+    receiveObjectOnlyFromJs({
+      count: 100,
+      callback: (err: Error | null, count: number) => {
+        if (err) {
+          reject(err)
+        } else {
+          t.is(count, 100)
+          resolve()
+        }
+      },
+    })
+  })
+})
+
 const Napi5Test = Number(process.versions.napi) >= 5 ? test : test.skip
 
 Napi5Test('Date test', (t) => {

examples/napi/index.d.ts

@@ -162,6 +162,11 @@ export interface TsTypeChanged {
 }
 export function createObjWithProperty(): { value: ArrayBuffer, get getter(): number }
 export function getterFromObj(): number
+export interface ObjectOnlyFromJs {
+  count: number
+  callback: (err: Error | null, value: number) => any
+}
+export function receiveObjectOnlyFromJs(obj: { count: number, callback: (err: Error | null, count: number) => void }): void
 export function asyncPlus100(p: Promise<number>): Promise<number>
 /** This is an interface for package.json */
 export interface PackageJson {

examples/napi/src/object.rs

@@ -1,4 +1,7 @@
-use napi::{bindgen_prelude::*, JsGlobal, JsNull, JsObject, JsUndefined, Property};
+use napi::{
+  bindgen_prelude::*, threadsafe_function::ThreadsafeFunction, JsGlobal, JsNull, JsObject,
+  JsUndefined, Property,
+};
 
 #[napi]
 fn list_obj_keys(obj: Object) -> Vec<String> {
@@ -101,3 +104,23 @@ pub fn create_obj_with_property(env: Env) -> Result<JsObject> {
 fn getter_from_obj() -> u32 {
   42
 }
+
+#[napi(object, object_to_js = false)]
+struct ObjectOnlyFromJs {
+  pub count: u32,
+  pub callback: ThreadsafeFunction<u32>,
+}
+
+#[napi]
+fn receive_object_only_from_js(
+  #[napi(ts_arg_type = "{ count: number, callback: (err: Error | null, count: number) => void }")]
+  obj: ObjectOnlyFromJs,
+) {
+  let ObjectOnlyFromJs { callback, count } = obj;
+  std::thread::spawn(move || {
+    callback.call(
+      Ok(count),
+      napi::threadsafe_function::ThreadsafeFunctionCallMode::NonBlocking,
+    );
+  });
+}