test: add env#wrap tests

test_module/__test__/class.spec.ts

@@ -11,3 +11,11 @@ test('should create class', (t) => {
   testClass.addCount(add)
   t.is(testClass.count, fixture + add)
 })
+
+test('should be able to manipulate wrapped native value', (t) => {
+  const TestClass = bindings.createTestClass()
+  const fixture = 20
+  const testClass = new TestClass(fixture)
+  const add = 101
+  t.is(testClass.addNativeCount(add), fixture + add + 100)
+})

test_module/src/class.rs

@@ -2,10 +2,15 @@ use std::convert::TryInto;
 
 use napi::{CallContext, JsFunction, JsNumber, JsObject, JsUndefined, Module, Property, Result};
 
+struct NativeClass {
+  value: i32,
+}
+
 #[js_function(1)]
 fn create_test_class(ctx: CallContext) -> Result<JsFunction> {
   let add_count_method = Property::new(&ctx.env, "addCount")?.with_method(add_count);
-  let properties = vec![add_count_method];
+  let add_native_count = Property::new(&ctx.env, "addNativeCount")?.with_method(add_native_count);
+  let properties = vec![add_count_method, add_native_count];
   ctx
     .env
     .define_class("TestClass", test_class_constructor, properties.as_slice())
@@ -13,9 +18,12 @@ fn create_test_class(ctx: CallContext) -> Result<JsFunction> {
 
 #[js_function(1)]
 fn test_class_constructor(ctx: CallContext) -> Result<JsUndefined> {
-  let count = ctx.get::<JsNumber>(0)?;
+  let count: i32 = ctx.get::<JsNumber>(0)?.try_into()?;
   let mut this: JsObject = ctx.this_unchecked();
-  this.set_named_property("count", ctx.env.create_int32(count.try_into()?)?)?;
+  ctx
+    .env
+    .wrap(&mut this, NativeClass { value: count + 100 })?;
+  this.set_named_property("count", ctx.env.create_int32(count)?)?;
   ctx.env.get_undefined()
 }
 
@@ -28,6 +36,15 @@ fn add_count(ctx: CallContext) -> Result<JsUndefined> {
   ctx.env.get_undefined()
 }
 
+#[js_function(1)]
+fn add_native_count(ctx: CallContext) -> Result<JsNumber> {
+  let add: i32 = ctx.get::<JsNumber>(0)?.try_into()?;
+  let this: JsObject = ctx.this_unchecked();
+  let native_class: &mut NativeClass = ctx.env.unwrap(&this)?;
+  native_class.value = native_class.value + add;
+  ctx.env.create_int32(native_class.value)
+}
+
 pub fn register_js(module: &mut Module) -> Result<()> {
   module.create_named_method("createTestClass", create_test_class)?;
   Ok(())