fix(overmind): properly copy nested arrays in json

Author: christianalfoni

packages/node_modules/overmind/src/utils.ts

@@ -1,7 +1,8 @@
 import isPlainObject from 'is-plain-obj'
 import { IMutation } from 'proxy-state-tree'
-import { safeValues } from './Devtools'
+
 import { Derived } from './derived'
+import { safeValues } from './Devtools'
 
 export const IS_TEST = process.env.NODE_ENV === 'test'
 export const IS_OPERATOR = Symbol('operator')
@@ -82,10 +83,10 @@ export function deepCopy(obj) {
       const isAGetter = originalDescriptor && 'get' in originalDescriptor
       const value = obj[key]
 
-      if (isPlainObject(value) && !isAGetter) {
-        aggr[key] = deepCopy(value)
-      } else {
+      if (isAGetter) {
         Object.defineProperty(aggr, key, originalDescriptor as any)
+      } else {
+        aggr[key] = deepCopy(value)
       }
 
       return aggr