refactor: simpleState now uses Property

packages/entity/trait.js

@@ -1,6 +1,7 @@
 import * as I from 'immutable';
 
 import {Resource} from '@avocado/resource';
+import {Property} from '@avocado/mixins';
 
 export class Trait {
 
@@ -81,20 +82,17 @@ export class Trait {
 
 }
 
-export function simpleState(name) {
+export function simpleState(key, meta = {}) {
   return (Superclass) => {
-    class SimpleState extends Superclass {}
-    // Add simple state handler.
-    Object.defineProperty(SimpleState.prototype, name, {
-      get() {
-        return this.state.get(name);
-      },
-      set(value) {
-        this.state = this.state.set(name, value);
-      },
-      enumerable: true,
-      configurable: true,
-    });
-    return SimpleState;
+    meta.emit = meta.emit || function(...args) {
+      this.entity.emit(...args);
+    };
+    meta.get = meta.get || function(value) {
+      return this.state.get(key);
+    };
+    meta.set = meta.set || function(value) {
+      this.state = this.state.set(key, value);
+    };
+    return Property(key, meta)(Superclass);
   }
 }