[Fiber] Add more tests for scheduling (#8183)

* Add more tests for scheduling

* Remove ambiguous terms

scripts/fiber/tests-passing.txt

@@ -795,9 +795,27 @@ src/renderers/shared/fiber/__tests__/ReactIncrementalReflection-test.js
 * finds no node before insertion and correct node before deletion
 
 src/renderers/shared/fiber/__tests__/ReactIncrementalScheduling-test.js
-* schedules multiple roots
-* works on deferred roots in the order they were scheduled
-* works on roots with animation priority before deferred work
+* schedules and flushes hi-pri work
+* schedules and flushes hi-pri work for many roots
+* flushes all scheduled hi-pri work
+* flushes all scheduled hi-pri work for many roots
+* schedules and flushes lo-pri work
+* schedules and flushes lo-pri work for many roots
+* flushes scheduled lo-pri work fitting within deadline
+* flushes scheduled lo-pri work fitting within deadline for many roots
+* schedules more lo-pri work if it runs out of time
+* schedules more lo-pri work if it runs out of time with many roots
+* FIXME: flushes late hi-pri work in a lo-pri callback if it wins
+* FIXME: flushes late hi-pri work in a lo-pri callback if it wins with many roots
+* FIXME: ignores late hi-pri work in a hi-pri callback if it wins
+* FIXME: ignores late hi-pri work in a hi-pri callback if it wins with many roots
+* FIXME: ignores all work in a lo-pri callback if it wins
+* FIXME: ignores all work in a lo-pri callback if it wins with many roots
+* flushes root with late lo-pri work in a hi-pri callback if it wins
+* flushes all roots with hi-pri work in a hi-pri callback if it wins
+* splits lo-pri work on multiple roots
+* works on lo-pri roots in the order they were scheduled
+* handles interleaved lo-pri and hi-pri work
 
 src/renderers/shared/fiber/__tests__/ReactIncrementalSideEffects-test.js
 * can update child nodes of a host instance

src/renderers/noop/ReactNoop.js

@@ -136,10 +136,22 @@ var NoopRenderer = ReactFiberReconciler({
   },
 
   scheduleAnimationCallback(callback) {
+    if (scheduledAnimationCallback) {
+      throw new Error(
+        'Scheduling an animation callback twice is excessive. ' +
+        'Instead, keep track of whether the callback has already been scheduled.'
+      );
+    }
     scheduledAnimationCallback = callback;
   },
 
   scheduleDeferredCallback(callback) {
+    if (scheduledDeferredCallback) {
+      throw new Error(
+        'Scheduling deferred callback twice is excessive. ' +
+        'Instead, keep track of whether the callback has already been scheduled.'
+      );
+    }
     scheduledDeferredCallback = callback;
   },
 
@@ -160,6 +172,14 @@ var ReactNoop = {
     }
   },
 
+  hasScheduledDeferredCallback() {
+    return Boolean(scheduledDeferredCallback);
+  },
+
+  hasScheduledAnimationCallback() {
+    return Boolean(scheduledAnimationCallback);
+  },
+
   // Shortcut for testing a single root
   render(element : ReactElement<any>, callback: ?Function) {
     ReactNoop.renderToRootWithID(element, DEFAULT_ROOT_ID, callback);

src/renderers/shared/fiber/__tests__/ReactCoroutine-test.js

@@ -17,6 +17,7 @@ var ReactCoroutine;
 
 describe('ReactCoroutine', () => {
   beforeEach(() => {
+    jest.resetModuleRegistry();
     React = require('React');
     ReactNoop = require('ReactNoop');
     ReactCoroutine = require('ReactCoroutine');

src/renderers/shared/fiber/__tests__/ReactIncremental-test.js

@@ -16,6 +16,7 @@ var ReactNoop;
 
 describe('ReactIncremental', () => {
   beforeEach(() => {
+    jest.resetModuleRegistry();
     React = require('React');
     ReactNoop = require('ReactNoop');
   });

src/renderers/shared/fiber/__tests__/ReactIncrementalReflection-test.js

@@ -16,6 +16,7 @@ var ReactNoop;
 
 describe('ReactIncrementalReflection', () => {
   beforeEach(() => {
+    jest.resetModuleRegistry();
     React = require('React');
     ReactNoop = require('ReactNoop');
   });