From 5ede7fb6191c7c587cf7099d044746d1607cd8d5 Mon Sep 17 00:00:00 2001
From: Pete Hunt <pete@instagram.com>
Date: Mon, 10 Mar 2014 15:27:36 -0700
Subject: [PATCH] ReactDOMComponent optimization

Slight optimization to not do unneeded reconciles of DOM components
---
 src/{core => browser}/__tests__/ReactDOM-test.js         | 0
 src/browser/ui/ReactDOMComponent.js                      | 9 +++++++++
 .../ui}/__tests__/ReactDOMComponent-test.js              | 0
 3 files changed, 9 insertions(+)
 rename src/{core => browser}/__tests__/ReactDOM-test.js (100%)
 rename src/{core => browser/ui}/__tests__/ReactDOMComponent-test.js (100%)

diff --git a/src/core/__tests__/ReactDOM-test.js b/src/browser/__tests__/ReactDOM-test.js
similarity index 100%
rename from src/core/__tests__/ReactDOM-test.js
rename to src/browser/__tests__/ReactDOM-test.js
diff --git a/src/browser/ui/ReactDOMComponent.js b/src/browser/ui/ReactDOMComponent.js
index cbe512a74a..5b1eface68 100644
--- a/src/browser/ui/ReactDOMComponent.js
+++ b/src/browser/ui/ReactDOMComponent.js
@@ -206,6 +206,15 @@ ReactDOMComponent.Mixin = {
   },
 
   receiveComponent: function(nextComponent, transaction) {
+    if (nextComponent === this) {
+      // Since props and context are immutable after the component is
+      // mounted, we can do a cheap identity compare here to determine
+      // if this is a superfluous reconcile.
+
+      // TODO: compare the descriptor
+      return;
+    }
+
     assertValidProps(nextComponent.props);
     ReactComponent.Mixin.receiveComponent.call(
       this,
diff --git a/src/core/__tests__/ReactDOMComponent-test.js b/src/browser/ui/__tests__/ReactDOMComponent-test.js
similarity index 100%
rename from src/core/__tests__/ReactDOMComponent-test.js
rename to src/browser/ui/__tests__/ReactDOMComponent-test.js