From c8a7988bf9e59df6db89192f87c22a550fc10d49 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Wed, 11 May 2016 23:27:45 +0100
Subject: [PATCH] Add a failing test case for #6742
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getOperations() blows up when replacing null with a native because the null component has debugID of 0 that isn’t registered in the component tree.
---
 src/isomorphic/__tests__/ReactPerf-test.js | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/isomorphic/__tests__/ReactPerf-test.js b/src/isomorphic/__tests__/ReactPerf-test.js
index 98df00938b..456ce9011e 100644
--- a/src/isomorphic/__tests__/ReactPerf-test.js
+++ b/src/isomorphic/__tests__/ReactPerf-test.js
@@ -67,6 +67,13 @@ describe('ReactPerf', function() {
     ReactPerf.start();
     fn();
     ReactPerf.stop();
+
+    // Make sure none of the methods crash.
+    ReactPerf.getWasted();
+    ReactPerf.getInclusive();
+    ReactPerf.getExclusive();
+    ReactPerf.getOperations();
+
     return ReactPerf.getLastMeasurements();
   }
 
@@ -208,6 +215,32 @@ describe('ReactPerf', function() {
     });
   });
 
+  it('should not count replacing null with a native as waste', function() {
+    var element = null;
+    function Foo () {
+      return element;
+    }
+    var container = document.createElement('div');
+    ReactDOM.render(<Foo />, container);
+    expectNoWaste(() => {
+      element = <div />;
+      ReactDOM.render(<Foo />, container);
+    });
+  });
+
+  it('should not count replacing a native with null as waste', function() {
+    var element = <div />;
+    function Foo () {
+      return element;
+    }
+    var container = document.createElement('div');
+    ReactDOM.render(<Foo />, container);
+    expectNoWaste(() => {
+      element = null;
+      ReactDOM.render(<Foo />, container);
+    });
+  });
+
   it('warns once when using getMeasurementsSummaryMap', function() {
     var measurements = measure(() => {});
     spyOn(console, 'error');