feat: Entity::mergeDiff

packages/entity/index.js

@@ -1,8 +1,13 @@
-import * as I from 'immutable';
 import D from 'debug';
 import without from 'lodash.without';
 
-import {compose, EventEmitter, fastApply} from '@avocado/core';
+import {
+  compose,
+  EventEmitter,
+  fastApply,
+  merge,
+  mergeDiff,
+} from '@avocado/core';
 import {Resource} from '@avocado/resource';
 import {Synchronized} from '@avocado/state';
 
@@ -85,9 +90,25 @@ let numericUid = 1;
 
 export class Entity extends decorate(Resource) {
 
-  constructor(json) {
+  static jsonWithDefaults(json) {
+    if ('undefined' === typeof json) {
+      return;
+    }
+    const pristine = JSON.parse(JSON.stringify(json));
+    for (const type in json.traits) {
+      if (!hasTrait(type)) {
+        continue;
+      }
+      const Trait = lookupTrait(type);
+      pristine.traits[type] = merge({}, Trait.defaultJSON(), json.traits[type]);
+    }
+    return pristine;
+  }
+
+  constructor(json, jsonext) {
     super();
     this._hooks = {};
+    this._json = Entity.jsonWithDefaults(json);
     this._traits = {};
     this._traitsFlat = [];
     this._traitTickers = [];
@@ -104,7 +125,7 @@ export class Entity extends decorate(Resource) {
     this.visibleAabb = [0, 0, 0, 0];
     // Fast path for instance.
     if ('undefined' !== typeof json) {
-      this.fromJSON(json);
+      this.fromJSON(merge({}, json, jsonext));
     }
   }
 
@@ -228,6 +249,10 @@ export class Entity extends decorate(Resource) {
     return type in this._traits;
   }
 
+  mergeDiff() {
+    return mergeDiff(this._json, this.toJSON());
+  }
+
   packetsForUpdate(force = false) {
     const packets = [];
     if (force) {