feat(napi-derive): allow injecting this in class method

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

@@ -254,6 +254,7 @@ Generated by [AVA](https://avajs.dev).
       static newRaph(): NinjaTurtle␊
       getMaskColor(): string␊
       getName(): string␊
+      returnThis(this: this): this␊
     }␊
     export type JsAssets = Assets␊
     export class Assets {␊

examples/napi/__test__/values.spec.ts

@@ -21,6 +21,7 @@ import {
   getCwd,
   Animal,
   Kind,
+  NinjaTurtle,
   ClassWithFactory,
   CustomNumEnum,
   Context,
@@ -173,6 +174,8 @@ test('class', (t) => {
   t.is(dog.type, Kind.Cat)
   const assets = new Assets()
   t.is(assets.get(1)?.filePath, 1)
+  const turtle = NinjaTurtle.newRaph()
+  t.is(turtle.returnThis(), turtle)
 })
 
 test('class factory', (t) => {

examples/napi/index.d.ts

@@ -244,6 +244,7 @@ export class NinjaTurtle {
   static newRaph(): NinjaTurtle
   getMaskColor(): string
   getName(): string
+  returnThis(this: this): this
 }
 export type JsAssets = Assets
 export class Assets {

examples/napi/src/class.rs

@@ -1,5 +1,5 @@
 use napi::{
-  bindgen_prelude::{Buffer, ClassInstance},
+  bindgen_prelude::{Buffer, ClassInstance, This},
   Env, Result,
 };
 
@@ -229,6 +229,11 @@ impl NinjaTurtle {
   pub fn get_name(&self) -> &str {
     self.name.as_str()
   }
+
+  #[napi]
+  pub fn return_this(&self, this: This) -> This {
+    this
+  }
 }
 
 #[napi(js_name = "Assets")]