From c4fb68aed9e5b85ddc8870445ae7287883259a9f Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Sat, 17 Dec 2016 01:02:45 +0000
Subject: [PATCH 1/4] Add a failing test for recursion check

---
 .../dom/fiber/__tests__/ReactDOMFiber-test.js          | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
index 990ad069d1e1..4d978932027f 100644
--- a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
+++ b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
@@ -993,5 +993,15 @@ describe('ReactDOMFiber', () => {
         'leave parent', // Only when we leave the portal does onMouseLeave fire.
       ]);
     });
+
+    it('should not crash encountering low-priority tree', () => {
+      var container = document.createElement('div');
+      ReactDOM.render(
+        <div hidden={true}>
+          <div />
+        </div>,
+        container
+      );
+    });
   }
 });

From aa13be322808a1a8869cb4ddd472c2bcb1ad0d19 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Sat, 17 Dec 2016 01:06:50 +0000
Subject: [PATCH 2/4] Make requestIdleCallback() and requestAnimationFrame()
 shims async

They no longer need to be sync in tests because we already made DOM renderer sync by default.
This fixes a crash when testing incrementalness in DOM renderer itself.
---
 scripts/fiber/tests-passing.txt | 1 +
 scripts/jest/environment.js     | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/scripts/fiber/tests-passing.txt b/scripts/fiber/tests-passing.txt
index 78ed9f2cdf4c..3771b9694411 100644
--- a/scripts/fiber/tests-passing.txt
+++ b/scripts/fiber/tests-passing.txt
@@ -537,6 +537,7 @@ src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
 * findDOMNode should find dom element after expanding a fragment
 * should bubble events from the portal to the parent
 * should not onMouseLeave when staying in the portal
+* should not crash encountering low-priority tree
 
 src/renderers/dom/shared/__tests__/CSSProperty-test.js
 * should generate browser prefixes for its `isUnitlessNumber`
diff --git a/scripts/jest/environment.js b/scripts/jest/environment.js
index 6b0c38fe49d7..83188a24a606 100644
--- a/scripts/jest/environment.js
+++ b/scripts/jest/environment.js
@@ -1,11 +1,13 @@
 /* eslint-disable */
 global.__DEV__ = true;
 
-// For testing DOM Fiber, we synchronously invoke all the scheduling.
+// For testing DOM Fiber.
 global.requestAnimationFrame = function(callback) {
-  callback();
+  setTimeout(callback);
 };
 
 global.requestIdleCallback = function(callback) {
-  callback({ timeRemaining() { return Infinity; } });
+  setTimeout(() => {
+    callback({ timeRemaining() { return Infinity; } })
+  });
 };

From f0ec04a29e322578aeb7ec9f28fc84a3f43bca8d Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Sat, 17 Dec 2016 01:14:32 +0000
Subject: [PATCH 3/4] Style fix

---
 scripts/jest/environment.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/jest/environment.js b/scripts/jest/environment.js
index 83188a24a606..98aa77b5591c 100644
--- a/scripts/jest/environment.js
+++ b/scripts/jest/environment.js
@@ -8,6 +8,6 @@ global.requestAnimationFrame = function(callback) {
 
 global.requestIdleCallback = function(callback) {
   setTimeout(() => {
-    callback({ timeRemaining() { return Infinity; } })
+    callback({ timeRemaining() { return Infinity; } });
   });
 };

From 647cd74adfd7d77805bc00d46d63605476ff9d75 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Sat, 17 Dec 2016 11:44:12 +0000
Subject: [PATCH 4/4] Fix lint

---
 src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
index 4d978932027f..9abec3eedd1b 100644
--- a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
+++ b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
@@ -995,7 +995,6 @@ describe('ReactDOMFiber', () => {
     });
 
     it('should not crash encountering low-priority tree', () => {
-      var container = document.createElement('div');
       ReactDOM.render(
         <div hidden={true}>
           <div />