Merge pull request #1064 from napi-rs/feature/obj-property-value

feat(napi): `with_value` method on `Property`

crates/napi/src/bindgen_runtime/module_register.rs

@@ -211,6 +211,38 @@ pub fn get_js_function(raw_fn: ExportRegisterCallback) -> Result<JsFunction> {
     })
 }
 
+/// Get `C Callback` from defined Rust `fn`
+/// ```rust
+/// #[napi]
+/// fn some_fn() -> u32 {
+///     1
+/// }
+///
+/// #[napi]
+/// fn create_obj(env: Env) -> Result<JsObject> {
+///     let mut obj = env.create_object()?;
+///     obj.define_property(&[Property::new("getter")?.with_getter(get_c_callback(some_fn_js_function)?)])?;
+///     Ok(obj)
+/// }
+/// ```
+///
+/// ```js
+/// console.log(createObj().getter) // 1
+/// ```
+///
+pub fn get_c_callback(raw_fn: ExportRegisterCallback) -> Result<crate::Callback> {
+  FN_REGISTER_MAP
+    .borrow_mut()
+    .get(&raw_fn)
+    .and_then(|(_env, cb, _name)| *cb)
+    .ok_or_else(|| {
+      crate::Error::new(
+        crate::Status::InvalidArg,
+        "JavaScript function does not exists".to_owned(),
+      )
+    })
+}
+
 #[no_mangle]
 unsafe extern "C" fn napi_register_module_v1(
   env: sys::napi_env,

crates/napi/src/env.rs

@@ -31,7 +31,7 @@ use serde::Serialize;
 #[cfg(all(feature = "tokio_rt", feature = "napi4"))]
 use std::future::Future;
 
-pub type Callback = extern "C" fn(sys::napi_env, sys::napi_callback_info) -> sys::napi_value;
+pub type Callback = unsafe extern "C" fn(sys::napi_env, sys::napi_callback_info) -> sys::napi_value;
 
 #[derive(Clone, Copy)]
 /// `Env` is used to represent a context that the underlying N-API implementation can use to persist VM-specific state.

crates/napi/src/js_values/object_property.rs

@@ -2,18 +2,33 @@ use std::convert::From;
 use std::ffi::CString;
 use std::ptr;
 
-use crate::{sys, Callback, Result};
+use crate::{sys, Callback, NapiRaw, Result};
 
-#[derive(Clone, Default)]
+#[derive(Clone)]
 pub struct Property {
   pub name: CString,
   getter: sys::napi_callback,
   setter: sys::napi_callback,
   method: sys::napi_callback,
   attrs: PropertyAttributes,
+  value: sys::napi_value,
   pub(crate) is_ctor: bool,
 }
 
+impl Default for Property {
+  fn default() -> Self {
+    Property {
+      name: Default::default(),
+      getter: Default::default(),
+      setter: Default::default(),
+      method: Default::default(),
+      attrs: Default::default(),
+      value: ptr::null_mut(),
+      is_ctor: Default::default(),
+    }
+  }
+}
+
 #[repr(i32)]
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum PropertyAttributes {
@@ -75,6 +90,11 @@ impl Property {
     self
   }
 
+  pub fn with_value<T: NapiRaw>(mut self, value: &T) -> Self {
+    self.value = unsafe { T::raw(value) };
+    self
+  }
+
   pub(crate) fn raw(&self) -> sys::napi_property_descriptor {
     sys::napi_property_descriptor {
       utf8name: self.name.as_ptr(),
@@ -82,7 +102,7 @@ impl Property {
       method: self.method,
       getter: self.getter,
       setter: self.setter,
-      value: ptr::null_mut(),
+      value: self.value,
       attributes: self.attrs.into(),
       data: ptr::null_mut(),
     }

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

@@ -112,6 +112,8 @@ Generated by [AVA](https://avajs.dev).
       typeOverride: object␊
       typeOverrideOptional?: object␊
     }␊
+    export function createObjWithProperty(): { value: ArrayBuffer, get getter(): number }␊
+    export function getterFromObj(): number␊
     export function asyncPlus100(p: Promise<number>): Promise<number>␊
     /** This is an interface for package.json */␊
     export interface PackageJson {␊

examples/napi/__test__/values.spec.ts

@@ -81,6 +81,7 @@ import {
   getStrFromObject,
   returnJsFunction,
   testSerdeRoundtrip,
+  createObjWithProperty,
 } from '../'
 
 test('export const', (t) => {
@@ -220,6 +221,12 @@ test('get str from object', (t) => {
   t.notThrows(() => getStrFromObject())
 })
 
+test('create object from Property', (t) => {
+  const obj = createObjWithProperty()
+  t.true(obj.value instanceof ArrayBuffer)
+  t.is(obj.getter, 42)
+})
+
 test('global', (t) => {
   t.is(getGlobal(), global)
 })

examples/napi/index.d.ts

@@ -102,6 +102,8 @@ export interface TsTypeChanged {
   typeOverride: object
   typeOverrideOptional?: object
 }
+export function createObjWithProperty(): { value: ArrayBuffer, get getter(): number }
+export function getterFromObj(): number
 export function asyncPlus100(p: Promise<number>): Promise<number>
 /** This is an interface for package.json */
 export interface PackageJson {

examples/napi/src/lib.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 #[macro_use]
 extern crate napi_derive;
 #[macro_use]

examples/napi/src/object.rs

@@ -1,4 +1,4 @@
-use napi::{bindgen_prelude::*, JsGlobal, JsNull, JsUndefined};
+use napi::{bindgen_prelude::*, JsGlobal, JsNull, JsObject, JsUndefined, Property};
 
 #[napi]
 fn list_obj_keys(obj: Object) -> Vec<String> {
@@ -85,3 +85,19 @@ pub struct TsTypeChanged {
   #[napi(ts_type = "object")]
   pub type_override_optional: Option<String>,
 }
+
+#[napi(ts_return_type = "{ value: ArrayBuffer, get getter(): number }")]
+pub fn create_obj_with_property(env: Env) -> Result<JsObject> {
+  let mut obj = env.create_object()?;
+  let arraybuffer = env.create_arraybuffer(10)?.into_raw();
+  obj.define_properties(&[
+    Property::new("value")?.with_value(&arraybuffer),
+    Property::new("getter")?.with_getter(get_c_callback(getter_from_obj_js_function)?),
+  ])?;
+  Ok(obj)
+}
+
+#[napi]
+fn getter_from_obj() -> u32 {
+  42
+}