Merge pull request #1177 from napi-rs/iterator-default-constructor

fix(napi): missing iterator implementation from class factory

crates/backend/src/codegen/fn.rs

@@ -294,7 +294,13 @@ impl NapiFn {
         }
       } else if self.kind == FnKind::Factory {
         if self.is_ret_result {
+          if self.parent_is_generator {
+            quote! { cb.generator_factory(#js_name, #ret?) }
+          } else {
             quote! { cb.factory(#js_name, #ret?) }
+          }
+        } else if self.parent_is_generator {
+          quote! { cb.generator_factory(#js_name, #ret) }
         } else {
           quote! { cb.factory(#js_name, #ret) }
         }

crates/napi/src/bindgen_runtime/callback_info.rs

@@ -113,43 +113,59 @@ impl<const N: usize> CallbackInfo<N> {
   }
 
   pub fn factory<T: 'static>(&self, js_name: &str, obj: T) -> Result<sys::napi_value> {
+    self._factory(js_name, obj).map(|(value, _)| value)
+  }
+
+  pub fn generator_factory<T: Generator + 'static>(
+    &self,
+    js_name: &str,
+    obj: T,
+  ) -> Result<sys::napi_value> {
+    let (instance, generator_ptr) = self._factory(js_name, obj)?;
+    crate::__private::create_iterator(self.env, instance, generator_ptr);
+    Ok(instance)
+  }
+
+  fn _factory<T: 'static>(&self, js_name: &str, obj: T) -> Result<(sys::napi_value, *mut T)> {
     let this = self.this();
     let mut instance = ptr::null_mut();
-    unsafe {
     let inner = ___CALL_FROM_FACTORY.get_or_default();
     inner.store(true, Ordering::Relaxed);
-      let status = sys::napi_new_instance(self.env, this, 0, ptr::null_mut(), &mut instance);
+    let status =
+      unsafe { sys::napi_new_instance(self.env, this, 0, ptr::null_mut(), &mut instance) };
     inner.store(false, Ordering::Relaxed);
     // Error thrown in `constructor`
     if status == sys::Status::napi_pending_exception {
       let mut exception = ptr::null_mut();
-        sys::napi_get_and_clear_last_exception(self.env, &mut exception);
-        sys::napi_throw(self.env, exception);
-        return Ok(ptr::null_mut());
+      unsafe { sys::napi_get_and_clear_last_exception(self.env, &mut exception) };
+      unsafe { sys::napi_throw(self.env, exception) };
+      return Ok((ptr::null_mut(), ptr::null_mut()));
     }
     let obj = Box::new(obj);
     let initial_finalize: Box<dyn FnOnce()> = Box::new(|| {});
-      let finalize_callbacks_ptr =
-        Rc::into_raw(Rc::new(Cell::new(Box::into_raw(initial_finalize))));
+    let finalize_callbacks_ptr = Rc::into_raw(Rc::new(Cell::new(Box::into_raw(initial_finalize))));
     let mut object_ref = ptr::null_mut();
-      let value_ref = Box::into_raw(obj) as *mut c_void;
+    let value_ref = Box::into_raw(obj);
     check_status!(
+      unsafe {
         sys::napi_wrap(
           self.env,
           instance,
-          value_ref,
+          value_ref as *mut c_void,
           Some(raw_finalize_unchecked::<T>),
           ptr::null_mut(),
-          &mut object_ref
-        ),
+          &mut object_ref,
+        )
+      },
       "Failed to initialize class `{}`",
       js_name,
     )?;
 
-      Reference::<T>::add_ref(value_ref, (value_ref, object_ref, finalize_callbacks_ptr));
-    };
-
-    Ok(instance)
+    Reference::<T>::add_ref(
+      value_ref as *mut c_void,
+      (value_ref as *mut c_void, object_ref, finalize_callbacks_ptr),
+    );
+    Ok((instance, value_ref))
   }
 
   pub fn unwrap_borrow_mut<T>(&mut self) -> Result<&'static mut T>

examples/napi/__test__/generator.spec.ts

@@ -1,9 +1,14 @@
 import test from 'ava'
 
-import { Fib } from '../index'
+import { Fib, Fib2, Fib3 } from '../index'
 
-test('should be able to stop a generator', (t) => {
-  const fib = new Fib()
+for (const [index, factory] of [
+  () => new Fib(),
+  () => Fib2.create(0),
+  () => new Fib3(0, 1),
+].entries()) {
+  test(`should be able to stop a generator #${index}`, (t) => {
+    const fib = factory()
     const gen = fib[Symbol.iterator]
     t.is(typeof gen, 'function')
     const iterator = gen()
@@ -25,10 +30,10 @@ test('should be able to stop a generator', (t) => {
     t.deepEqual(iterator.next(), {
       done: true,
     })
-})
+  })
 
-test('should be able to throw to generator', (t) => {
-  const fib = new Fib()
+  test(`should be able to throw to generator #${index}`, (t) => {
+    const fib = factory()
     const gen = fib[Symbol.iterator]
     t.is(typeof gen, 'function')
     const iterator = gen()
@@ -48,4 +53,5 @@ test('should be able to throw to generator', (t) => {
     t.deepEqual(iterator.next(), {
       done: true,
     })
-})
+  })
+}

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

@@ -268,6 +268,16 @@ Generated by [AVA](https://avajs.dev).
       [Symbol.iterator](): Iterator<number, void, number>␊
       constructor()␊
     }␊
+    export class Fib2 {␊
+      [Symbol.iterator](): Iterator<number, void, number>␊
+      static create(seed: number): Fib2␊
+    }␊
+    export class Fib3 {␊
+      current: number␊
+      next: number␊
+      constructor(current: number, next: number)␊
+      [Symbol.iterator](): Iterator<number, void, number>␊
+    }␊
     export class JsRepo {␊
       constructor(dir: string)␊
       remote(): JsRemote␊

examples/napi/index.d.ts

@@ -258,6 +258,16 @@ export class Fib {
   [Symbol.iterator](): Iterator<number, void, number>
   constructor()
 }
+export class Fib2 {
+  [Symbol.iterator](): Iterator<number, void, number>
+  static create(seed: number): Fib2
+}
+export class Fib3 {
+  current: number
+  next: number
+  constructor(current: number, next: number)
+  [Symbol.iterator](): Iterator<number, void, number>
+}
 export class JsRepo {
   constructor(dir: string)
   remote(): JsRemote

examples/napi/src/generator.rs

@@ -40,3 +40,72 @@ impl Fib {
     }
   }
 }
+
+#[napi(iterator)]
+pub struct Fib2 {
+  current: u32,
+  next: u32,
+}
+
+#[napi]
+impl Generator for Fib2 {
+  type Yield = u32;
+  type Next = i32;
+  type Return = ();
+
+  fn next(&mut self, value: Option<Self::Next>) -> Option<Self::Yield> {
+    match value {
+      Some(n) => {
+        self.current = n as u32;
+        self.next = n as u32 + 1;
+      }
+      None => {
+        let next = self.next;
+        let current = self.current;
+        self.current = next;
+        self.next = current + next;
+      }
+    };
+    Some(self.current)
+  }
+}
+
+#[napi]
+impl Fib2 {
+  #[napi(factory)]
+  pub fn create(seed: u32) -> Self {
+    Self {
+      current: seed,
+      next: seed + 1,
+    }
+  }
+}
+
+#[napi(iterator, constructor)]
+pub struct Fib3 {
+  pub current: u32,
+  pub next: u32,
+}
+
+#[napi]
+impl Generator for Fib3 {
+  type Yield = u32;
+  type Next = i32;
+  type Return = ();
+
+  fn next(&mut self, value: Option<Self::Next>) -> Option<Self::Yield> {
+    match value {
+      Some(n) => {
+        self.current = n as u32;
+        self.next = n as u32 + 1;
+      }
+      None => {
+        let next = self.next;
+        let current = self.current;
+        self.current = next;
+        self.next = current + next;
+      }
+    };
+    Some(self.current)
+  }
+}