Merge pull request #1274 from napi-rs/weak-reference

feat(napi): add get and get_mut method on `WeakReference`

crates/backend/src/codegen/fn.rs

@@ -147,8 +147,8 @@ impl NapiFn {
                       if let Some(p) = path.path.segments.first() {
                         if p.ident == *self.parent.as_ref().unwrap() {
                           args.push(
-                              quote! { napi::bindgen_prelude::Reference::from_value_ptr(this_ptr as *mut std::ffi::c_void, env)? },
+                            quote! { napi::bindgen_prelude::Reference::from_value_ptr(this_ptr as *mut std::ffi::c_void, env)? },
-                            );
+                          );
                           skipped_arg_count += 1;
                           continue;
                         }

crates/napi/src/bindgen_runtime/js_values/value_ref.rs

@@ -180,6 +180,15 @@ impl<T> Clone for WeakReference<T> {
 
 impl<T: 'static> ToNapiValue for WeakReference<T> {
   unsafe fn to_napi_value(env: crate::sys::napi_env, val: Self) -> Result<crate::sys::napi_value> {
+    if Weak::strong_count(&val.finalize_callbacks) == 0 {
+      return Err(Error::new(
+        Status::GenericFailure,
+        format!(
+          "The original reference that WeakReference<{}> is pointing to is dropped",
+          std::any::type_name::<T>()
+        ),
+      ));
+    };
     let mut result = std::ptr::null_mut();
     check_status!(
       unsafe { crate::sys::napi_get_reference_value(env, val.napi_ref, &mut result) },
@@ -207,6 +216,22 @@ impl<T: 'static> WeakReference<T> {
       Ok(None)
     }
   }
+
+  pub fn get(&self) -> Option<&T> {
+    if Weak::strong_count(&self.finalize_callbacks) == 0 {
+      None
+    } else {
+      Some(unsafe { Box::leak(Box::from_raw(self.raw)) })
+    }
+  }
+
+  pub fn get_mut(&mut self) -> Option<&mut T> {
+    if Weak::strong_count(&self.finalize_callbacks) == 0 {
+      None
+    } else {
+      Some(unsafe { Box::leak(Box::from_raw(self.raw)) })
+    }
+  }
 }
 
 /// ### Experimental feature