progress

Author: ef4

packages/@ember/-internals/metal/lib/decorator.ts

@@ -7,6 +7,7 @@ import {
   identifyModernDecoratorArgs,
   isModernDecoratorArgs,
 } from './decorator-util';
+import { findDescriptor } from '@ember/-internals/utils/lib/lookup-descriptor';
 
 export type DecoratorPropertyDescriptor = (PropertyDescriptor & { initializer?: any }) | undefined;
 
@@ -167,45 +168,60 @@ function makeDescriptor(
   return computedDesc;
 }
 
+function once() {
+  let needsToRun = true;
+  return function (fn: () => void): void {
+    if (needsToRun) {
+      fn();
+      needsToRun = false;
+    }
+  };
+}
+
 function computedDecorator2023(args: Parameters<Decorator>, desc: ComputedDescriptor) {
   const dec = identifyModernDecoratorArgs(args);
-
-  let setup: undefined | ((prototype: any, propDesc: any) => void) = function (
-    prototype,
-    propDesc
-  ) {
-    desc.setup(prototype, dec.context.name as string, propDesc, metaFor(prototype));
-    setup = undefined;
-  };
+  let setup = once();
 
   switch (dec.kind) {
     case 'field':
       dec.context.addInitializer(function (this: any) {
-        setup?.(this.constructor.prototype, undefined);
+        setup(() => {
+          desc.setup(
+            this.constructor.prototype,
+            dec.context.name as string,
+            undefined,
+            metaFor(this.constructor.prototype)
+          );
+        });
         Object.defineProperty(
           this,
           dec.context.name,
           makeDescriptor(desc, dec.context.name as string)
         );
       });
-      break;
+      return undefined;
+    case 'setter':
     case 'getter': {
-      let propDesc = {
-        get: dec.value as any,
-      };
-      dec.context.addInitializer(function (this: any) {
-        setup?.(this.constructor.prototype, propDesc);
-      });
-      return makeDescriptor(desc, dec.context.name as string, propDesc).get;
-    }
-    case 'setter': {
-      let propDesc = {
-        set: dec.value as any,
-      };
       dec.context.addInitializer(function (this: any) {
-        setup?.(this.constructor.prototype, propDesc);
+        setup(() => {
+          let found = findDescriptor(this, dec.context.name);
+          if (!found) {
+            return;
+          }
+          desc.setup(
+            found.object,
+            dec.context.name as string,
+            found.descriptor,
+            metaFor(found.object)
+          );
+          Object.defineProperty(
+            found.object,
+            dec.context.name,
+            makeDescriptor(desc, dec.context.name as string, found.descriptor)
+          );
+        });
       });
-      return makeDescriptor(desc, dec.context.name as string, propDesc).set;
+      return undefined;
     }
     case 'method':
       assert(

packages/@ember/-internals/metal/tests/computed_decorator_test.js

@@ -71,6 +71,7 @@ moduleFor(
     ['@test computed property can be defined and accessed on a class constructor'](assert) {
       let count = 0;
 
+      debugger;
       class Obj {
         static bar = 123;
 

packages/@ember/-internals/utils/lib/lookup-descriptor.ts

@@ -1,11 +1,21 @@
-export default function lookupDescriptor(obj: object, keyName: string | symbol) {
+export function findDescriptor(
+  obj: object,
+  keyName: string | symbol
+): { object: object; descriptor: PropertyDescriptor } | null {
   let current: object | null = obj;
   do {
     let descriptor = Object.getOwnPropertyDescriptor(current, keyName);
     if (descriptor !== undefined) {
-      return descriptor;
+      return { descriptor, object: current };
     }
     current = Object.getPrototypeOf(current);
   } while (current !== null);
   return null;
 }
+
+export default function lookupDescriptor(
+  obj: object,
+  keyName: string | symbol
+): PropertyDescriptor | null {
+  return findDescriptor(obj, keyName)?.descriptor ?? null;
+}

packages/@ember/object/index.ts

@@ -16,6 +16,7 @@ import {
   identifyModernDecoratorArgs,
   isModernDecoratorArgs,
 } from '@ember/-internals/metal/lib/decorator-util';
+import { findDescriptor } from '@ember/-internals/utils/lib/lookup-descriptor';
 
 export {
   notifyPropertyChange,
@@ -328,11 +329,14 @@ function action2023(args: Parameters<Decorator>) {
   let needsSetup = true;
   dec.context.addInitializer(function (this: any) {
     if (needsSetup) {
-      Object.defineProperty(
-        this.constructor.prototype,
-        dec.context.name,
-        setupAction(this.constructor.prototype, dec.context.name, dec.value)
-      );
+      let found = findDescriptor(this, dec.context.name);
+      if (found?.object) {
+        Object.defineProperty(
+          found.object,
+          dec.context.name,
+          setupAction(found.object, dec.context.name, dec.value)
+        );
+      }
       needsSetup = false;
     }
   });