fix(withState): respect getters and setters of non hook properties

.changeset/plain-trams-kneel.md

@@ -0,0 +1,6 @@
+---
+'@envelop/core': patch
+---
+
+Fix getters and setters being stripped away. The value was copied at plugin creation instead of
+copying the getter and setter (if any).

packages/core/src/plugin-with-state.ts

@@ -62,9 +62,16 @@ export function withState<
 
   function addStateGetters(src: any) {
     const result: any = {};
-    for (const [hookName, hook] of Object.entries(src) as any) {
+    // Use the property descriptors to keep potential getters and setters, or not enumerable props
+    const properties = Object.entries(Object.getOwnPropertyDescriptors(src));
+    for (const [hookName, descriptor] of properties) {
+      const hook = descriptor.value;
       if (typeof hook !== 'function') {
-        result[hookName] = hook;
+        descriptor.get &&= () => src[hookName];
+        descriptor.set &&= value => {
+          src[hookName] = value;
+        };
+        Object.defineProperty(result, hookName, descriptor);
       } else {
         result[hookName] = {
           [hook.name](payload: any, ...args: any[]) {
@@ -88,11 +95,11 @@ export function withState<
     return result;
   }
 
-  const { instrumentation, ...hooks } = pluginFactory(getState as any);
+  const plugin = pluginFactory(getState as any);
 
-  const pluginWithState = addStateGetters(hooks);
-  if (instrumentation) {
-    pluginWithState.instrumentation = addStateGetters(instrumentation);
+  const pluginWithState = addStateGetters(plugin);
+  if (plugin.instrumentation) {
+    pluginWithState.instrumentation = addStateGetters(plugin.instrumentation);
   }
 
   return pluginWithState as P;

packages/core/test/plugin-with-state.spec.ts

@@ -77,7 +77,35 @@ describe('pluginWithState', () => {
     );
   });
 
-  describe('instruments', () => {
+  it('should allow to have getters and setters', () => {
+    const called = { getter: false, setter: false };
+    const plugin = withState<{ value: string; instrumentation?: never }>(() => ({
+      get value() {
+        called.getter = true;
+        return 'test';
+      },
+      set value(value) {
+        called.setter = true;
+        expect(value).toBe('value');
+      },
+    }));
+
+    plugin.value = 'value';
+    expect(plugin.value).toBe('test');
+    expect(called).toEqual({ getter: true, setter: true });
+  });
+
+  it('should allow to have not enumerable', () => {
+    const plugin = {};
+    Object.defineProperty(plugin, 'hidden', { value: 'test' });
+
+    const pluginWithState = withState(() => plugin);
+    // @ts-expect-error
+    expect(pluginWithState['hidden']).toBe('test');
+    expect(Object.keys(plugin)).toEqual([]);
+  });
+
+  describe('instrumentation', () => {
     const plugin = withState(() => ({ instrumentation: { hook: (...args: any[]): any => args } }));
 
     it('should add request state', () => {