From a5c19ce1da4c16e986dab3e267b43ee1f1fe03d6 Mon Sep 17 00:00:00 2001
From: LongYinan <lynweklm@gmail.com>
Date: Thu, 12 May 2022 15:11:47 +0800
Subject: [PATCH] fix(napi): type constraint for either types

---
 .../src/bindgen_runtime/js_values/either.rs   | 137 ++++++------------
 examples/napi/__test__/typegen.spec.ts.md     |   2 +
 examples/napi/__test__/typegen.spec.ts.snap   | Bin 3114 -> 3133 bytes
 examples/napi/__test__/values.spec.ts         |  11 ++
 examples/napi/index.d.ts                      |   2 +
 examples/napi/src/either.rs                   |  14 ++
 6 files changed, 73 insertions(+), 93 deletions(-)

diff --git a/crates/napi/src/bindgen_runtime/js_values/either.rs b/crates/napi/src/bindgen_runtime/js_values/either.rs
index a8bfe3f8..aab142b6 100644
--- a/crates/napi/src/bindgen_runtime/js_values/either.rs
+++ b/crates/napi/src/bindgen_runtime/js_values/either.rs
@@ -1,22 +1,18 @@
 use super::{FromNapiValue, ToNapiValue, TypeName};
-use crate::{sys, type_of, JsNull, JsUndefined, NapiRaw, Status, ValueType};
+use crate::{
+  bindgen_runtime::{Null, Undefined},
+  sys, type_of, JsUndefined, NapiRaw, Status, ValueType,
+};
 
 const ERROR_MSG: &str = "The return value of typeof(T) should not be equal in Either";
 
 #[derive(Debug, Clone, Copy)]
-pub enum Either<
-  A: TypeName + FromNapiValue + ToNapiValue,
-  B: TypeName + FromNapiValue + ToNapiValue,
-> {
+pub enum Either<A, B> {
   A(A),
   B(B),
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue + NapiRaw,
-    B: TypeName + FromNapiValue + ToNapiValue + NapiRaw,
-  > Either<A, B>
-{
+impl<A: NapiRaw, B: NapiRaw> Either<A, B> {
   /// # Safety
   /// Backward compatible with `Either` in **v1**
   pub unsafe fn raw(&self) -> sys::napi_value {
@@ -27,9 +23,7 @@ impl<
   }
 }
 
-impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + ToNapiValue> TypeName
-  for Either<A, B>
-{
+impl<A: TypeName, B: TypeName> TypeName for Either<A, B> {
   fn type_name() -> &'static str {
     "Either"
   }
@@ -40,7 +34,7 @@ impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + To
 }
 
 // Backwards compatibility with v1
-impl<T: TypeName + FromNapiValue + ToNapiValue> From<Either<T, JsUndefined>> for Option<T> {
+impl<T> From<Either<T, JsUndefined>> for Option<T> {
   fn from(value: Either<T, JsUndefined>) -> Option<T> {
     match value {
       Either::A(v) => Some(v),
@@ -49,8 +43,17 @@ impl<T: TypeName + FromNapiValue + ToNapiValue> From<Either<T, JsUndefined>> for
   }
 }
 
-impl<T: TypeName + FromNapiValue + ToNapiValue> From<Either<T, JsNull>> for Option<T> {
-  fn from(value: Either<T, JsNull>) -> Option<T> {
+impl<T> From<Option<T>> for Either<T, Undefined> {
+  fn from(value: Option<T>) -> Self {
+    match value {
+      Some(v) => Either::A(v),
+      None => Either::B(()),
+    }
+  }
+}
+
+impl<T> From<Either<T, Null>> for Option<T> {
+  fn from(value: Either<T, Null>) -> Option<T> {
     match value {
       Either::A(v) => Some(v),
       Either::B(_) => None,
@@ -58,9 +61,7 @@ impl<T: TypeName + FromNapiValue + ToNapiValue> From<Either<T, JsNull>> for Opti
   }
 }
 
-impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + ToNapiValue>
-  FromNapiValue for Either<A, B>
-{
+impl<A: TypeName + FromNapiValue, B: TypeName + FromNapiValue> FromNapiValue for Either<A, B> {
   unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
     debug_assert!(A::value_type() != B::value_type(), "{}", ERROR_MSG);
     let js_type = type_of!(env, napi_val)?;
@@ -82,9 +83,7 @@ impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + To
   }
 }
 
-impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + ToNapiValue>
-  ToNapiValue for Either<A, B>
-{
+impl<A: ToNapiValue, B: ToNapiValue> ToNapiValue for Either<A, B> {
   unsafe fn to_napi_value(
     env: sys::napi_env,
     value: Self,
@@ -97,22 +96,13 @@ impl<A: TypeName + FromNapiValue + ToNapiValue, B: TypeName + FromNapiValue + To
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Either3<
-  A: TypeName + FromNapiValue + ToNapiValue,
-  B: TypeName + FromNapiValue + ToNapiValue,
-  C: TypeName + FromNapiValue + ToNapiValue,
-> {
+pub enum Either3<A, B, C> {
   A(A),
   B(B),
   C(C),
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-  > TypeName for Either3<A, B, C>
-{
+impl<A: TypeName, B: TypeName, C: TypeName> TypeName for Either3<A, B, C> {
   fn type_name() -> &'static str {
     "Either3"
   }
@@ -122,11 +112,8 @@ impl<
   }
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-  > FromNapiValue for Either3<A, B, C>
+impl<A: TypeName + FromNapiValue, B: TypeName + FromNapiValue, C: TypeName + FromNapiValue>
+  FromNapiValue for Either3<A, B, C>
 {
   unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
     debug_assert!(
@@ -160,12 +147,7 @@ impl<
   }
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-  > ToNapiValue for Either3<A, B, C>
-{
+impl<A: ToNapiValue, B: ToNapiValue, C: ToNapiValue> ToNapiValue for Either3<A, B, C> {
   unsafe fn to_napi_value(
     env: sys::napi_env,
     value: Self,
@@ -179,25 +161,14 @@ impl<
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Either4<
-  A: TypeName + FromNapiValue + ToNapiValue,
-  B: TypeName + FromNapiValue + ToNapiValue,
-  C: TypeName + FromNapiValue + ToNapiValue,
-  D: TypeName + FromNapiValue + ToNapiValue,
-> {
+pub enum Either4<A, B, C, D> {
   A(A),
   B(B),
   C(C),
   D(D),
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
-  > TypeName for Either4<A, B, C, D>
-{
+impl<A: TypeName, B: TypeName, C: TypeName, D: TypeName> TypeName for Either4<A, B, C, D> {
   fn type_name() -> &'static str {
     "Either4"
   }
@@ -208,10 +179,10 @@ impl<
 }
 
 impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
+    A: TypeName + FromNapiValue,
+    B: TypeName + FromNapiValue,
+    C: TypeName + FromNapiValue,
+    D: TypeName + FromNapiValue,
   > FromNapiValue for Either4<A, B, C, D>
 {
   unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
@@ -254,12 +225,8 @@ impl<
   }
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
-  > ToNapiValue for Either4<A, B, C, D>
+impl<A: ToNapiValue, B: ToNapiValue, C: ToNapiValue, D: ToNapiValue> ToNapiValue
+  for Either4<A, B, C, D>
 {
   unsafe fn to_napi_value(
     env: sys::napi_env,
@@ -275,13 +242,7 @@ impl<
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Either5<
-  A: TypeName + FromNapiValue + ToNapiValue,
-  B: TypeName + FromNapiValue + ToNapiValue,
-  C: TypeName + FromNapiValue + ToNapiValue,
-  D: TypeName + FromNapiValue + ToNapiValue,
-  E: TypeName + FromNapiValue + ToNapiValue,
-> {
+pub enum Either5<A, B, C, D, E> {
   A(A),
   B(B),
   C(C),
@@ -289,13 +250,8 @@ pub enum Either5<
   E(E),
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
-    E: TypeName + FromNapiValue + ToNapiValue,
-  > TypeName for Either5<A, B, C, D, E>
+impl<A: TypeName, B: TypeName, C: TypeName, D: TypeName, E: TypeName> TypeName
+  for Either5<A, B, C, D, E>
 {
   fn type_name() -> &'static str {
     "Either5"
@@ -307,11 +263,11 @@ impl<
 }
 
 impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
-    E: TypeName + FromNapiValue + ToNapiValue,
+    A: TypeName + FromNapiValue,
+    B: TypeName + FromNapiValue,
+    C: TypeName + FromNapiValue,
+    D: TypeName + FromNapiValue,
+    E: TypeName + FromNapiValue,
   > FromNapiValue for Either5<A, B, C, D, E>
 {
   unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
@@ -358,13 +314,8 @@ impl<
   }
 }
 
-impl<
-    A: TypeName + FromNapiValue + ToNapiValue,
-    B: TypeName + FromNapiValue + ToNapiValue,
-    C: TypeName + FromNapiValue + ToNapiValue,
-    D: TypeName + FromNapiValue + ToNapiValue,
-    E: TypeName + FromNapiValue + ToNapiValue,
-  > ToNapiValue for Either5<A, B, C, D, E>
+impl<A: ToNapiValue, B: ToNapiValue, C: ToNapiValue, D: ToNapiValue, E: ToNapiValue> ToNapiValue
+  for Either5<A, B, C, D, E>
 {
   unsafe fn to_napi_value(
     env: sys::napi_env,
diff --git a/examples/napi/__test__/typegen.spec.ts.md b/examples/napi/__test__/typegen.spec.ts.md
index 700fd349..d22d65b1 100644
--- a/examples/napi/__test__/typegen.spec.ts.md
+++ b/examples/napi/__test__/typegen.spec.ts.md
@@ -57,6 +57,8 @@ Generated by [AVA](https://avajs.dev).
     export function either4(input: string | number | boolean | Obj): number␊
     export function receiveClassOrNumber(either: number | JsClassForEither): number␊
     export function receiveMutClassOrNumber(either: number | JsClassForEither): number␊
+    export function returnEitherClass(input: number): number | JsClassForEither␊
+    export function eitherFromOption(): JsClassForEither | undefined␊
     /** default enum values are continuos i32s start from 0 */␊
     export const enum Kind {␊
       /** Barks */␊
diff --git a/examples/napi/__test__/typegen.spec.ts.snap b/examples/napi/__test__/typegen.spec.ts.snap
index d3ff3d429dcc50e953f473a1a31edb899f7eea8e..6c9e20490804c8b59a9254b3eb1e1f186595e69d 100644
GIT binary patch
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diff --git a/examples/napi/__test__/values.spec.ts b/examples/napi/__test__/values.spec.ts
index e421c980..f1ad6054 100644
--- a/examples/napi/__test__/values.spec.ts
+++ b/examples/napi/__test__/values.spec.ts
@@ -93,6 +93,8 @@ import {
   CssStyleSheet,
   asyncReduceBuffer,
   callbackReturnPromise,
+  returnEitherClass,
+  eitherFromOption,
 } from '../'
 
 test('export const', (t) => {
@@ -467,6 +469,15 @@ test('receive class reference in either', (t) => {
   t.is(receiveMutClassOrNumber(c), 100)
 })
 
+test('return either class', (t) => {
+  t.is(returnEitherClass(1), 1)
+  t.true(returnEitherClass(-1) instanceof JsClassForEither)
+})
+
+test('either from option', (t) => {
+  t.true(eitherFromOption() instanceof JsClassForEither)
+})
+
 test('either3', (t) => {
   t.is(either3(2), 2)
   t.is(either3('hello'), 'hello'.length)
diff --git a/examples/napi/index.d.ts b/examples/napi/index.d.ts
index b50df571..d3adb048 100644
--- a/examples/napi/index.d.ts
+++ b/examples/napi/index.d.ts
@@ -47,6 +47,8 @@ export interface Obj {
 export function either4(input: string | number | boolean | Obj): number
 export function receiveClassOrNumber(either: number | JsClassForEither): number
 export function receiveMutClassOrNumber(either: number | JsClassForEither): number
+export function returnEitherClass(input: number): number | JsClassForEither
+export function eitherFromOption(): JsClassForEither | undefined
 /** default enum values are continuos i32s start from 0 */
 export const enum Kind {
   /** Barks */
diff --git a/examples/napi/src/either.rs b/examples/napi/src/either.rs
index 175de708..0f5fa8cd 100644
--- a/examples/napi/src/either.rs
+++ b/examples/napi/src/either.rs
@@ -82,3 +82,17 @@ fn receive_mut_class_or_number(either: Either<u32, &mut JsClassForEither>) -> u3
     Either::B(_) => 100,
   }
 }
+
+#[napi]
+fn return_either_class(input: i32) -> Either<u32, JsClassForEither> {
+  if input > 0 {
+    Either::A(input as u32)
+  } else {
+    Either::B(JsClassForEither {})
+  }
+}
+
+#[napi]
+fn either_from_option() -> Either<JsClassForEither, Undefined> {
+  Some(JsClassForEither {}).into()
+}