From c5af009ae7b31f26b6b1f6b909dbaa6679e3351e Mon Sep 17 00:00:00 2001
From: Anton Korzunov <thekashey@gmail.com>
Date: Thu, 11 Apr 2019 09:04:48 +1000
Subject: [PATCH] fix: remove Object.assign, fixes #1226

---
 src/adapters/preact.js        | 4 ++--
 src/configuration.js          | 9 +++++++++
 src/internal/getReactStack.js | 8 ++++----
 src/utils.dev.js              | 4 ++--
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/adapters/preact.js b/src/adapters/preact.js
index 0b5fb388d..993a170c8 100644
--- a/src/adapters/preact.js
+++ b/src/adapters/preact.js
@@ -1,4 +1,4 @@
-import configuration from '../configuration'
+import { setConfiguration } from '../configuration'
 
 const tune = {
   allowSFC: false,
@@ -7,7 +7,7 @@ const tune = {
 export const preactAdapter = (instance, resolveType) => {
   const oldHandler = instance.options.vnode
 
-  Object.assign(configuration, tune)
+  setConfiguration(tune)
 
   instance.options.vnode = vnode => {
     vnode.nodeName = resolveType(vnode.nodeName)
diff --git a/src/configuration.js b/src/configuration.js
index 9eeb81a00..b7830a9ec 100644
--- a/src/configuration.js
+++ b/src/configuration.js
@@ -44,4 +44,13 @@ export const internalConfiguration = {
   disableProxyCreation: false,
 }
 
+export const setConfiguration = config => {
+  // not using Object.assing for IE11 compliance
+  for (const i in config) {
+    if (config.hasOwnProperty(i)) {
+      configuration[i] = config[i]
+    }
+  }
+}
+
 export default configuration
diff --git a/src/internal/getReactStack.js b/src/internal/getReactStack.js
index 217cf1990..30fb12e87 100644
--- a/src/internal/getReactStack.js
+++ b/src/internal/getReactStack.js
@@ -36,10 +36,10 @@ const markUpdate = ({ fiber }) => {
   }
 
   if (fiber.memoizedProps && typeof fiber.memoizedProps === 'object') {
-    fiber.memoizedProps = Object.assign(
-      { cacheBusterProp: true },
-      fiber.memoizedProps,
-    )
+    fiber.memoizedProps = {
+      cacheBusterProp: true,
+      ...fiber.memoizedProps,
+    }
   }
 }
 
diff --git a/src/utils.dev.js b/src/utils.dev.js
index dbca1ef9b..457f9c55f 100644
--- a/src/utils.dev.js
+++ b/src/utils.dev.js
@@ -3,7 +3,7 @@ import {
   getProxyByType,
   setComponentOptions,
 } from './reconciler/proxies'
-import configuration from './configuration'
+import { setConfiguration } from './configuration'
 import { hotComponentCompare } from './reconciler/componentComparator'
 
 const getProxyOrType = type => {
@@ -25,4 +25,4 @@ export const cold = type => {
 export const configureComponent = (component, options) =>
   setComponentOptions(component, options)
 
-export const setConfig = config => Object.assign(configuration, config)
+export const setConfig = config => setConfiguration(config)