Codemod {...null} to {} in xplat/js

Summary:
Now that [exact_empty_objects has been enabled](https://fb.workplace.com/groups/flowlang/posts/1092665251339137), we can codemod `{...null}` to `{}` - they are now equivalent.

1) Run my one-off jscodeshift codemod
2) `scripts/flow/tool update-suppressions .` (as some suppressions move around due to the change)

drop-conflicts

Reviewed By: bradzacher

Differential Revision: D37834078

fbshipit-source-id: 6bf4913910e5597e5dd9d5161cd35deece6a7581

Author: gkz

Libraries/Animated/AnimatedImplementation.js

@@ -369,9 +369,7 @@ const parallel = function (
 ): CompositeAnimation {
   let doneCount = 0;
   // Make sure we only call stop() at most once for each animation
-  const hasEnded = {
-    ...null,
-  };
+  const hasEnded = {};
   const stopTogether = !(config && config.stopTogether === false);
 
   const result = {
@@ -463,9 +461,7 @@ type LoopAnimationConfig = {
 const loop = function (
   animation: CompositeAnimation,
   // $FlowFixMe[prop-missing]
-  {iterations = -1, resetBeforeIteration = true}: LoopAnimationConfig = {
-    ...null,
-  },
+  {iterations = -1, resetBeforeIteration = true}: LoopAnimationConfig = {},
 ): CompositeAnimation {
   let isFinished = false;
   let iterationsSoFar = 0;

Libraries/Animated/AnimatedMock.js

@@ -161,9 +161,7 @@ type LoopAnimationConfig = {
 const loop = function (
   animation: CompositeAnimation,
   // $FlowFixMe[prop-missing]
-  {iterations = -1}: LoopAnimationConfig = {
-    ...null,
-  },
+  {iterations = -1}: LoopAnimationConfig = {},
 ): CompositeAnimation {
   return emptyAnimation;
 };

Libraries/Animated/NativeAnimatedHelper.js

@@ -48,12 +48,8 @@ const useSingleOpBatching =
   ReactNativeFeatureFlags.animatedShouldUseSingleOp();
 let flushQueueTimeout = null;
 
-const eventListenerGetValueCallbacks = {
-  ...null,
-};
-const eventListenerAnimationFinishedCallbacks = {
-  ...null,
-};
+const eventListenerGetValueCallbacks = {};
+const eventListenerAnimationFinishedCallbacks = {};
 let globalEventEmitterGetValueListener: ?EventSubscription = null;
 let globalEventEmitterAnimationFinishedListener: ?EventSubscription = null;
 
@@ -82,17 +78,12 @@ const nativeOps: ?typeof NativeAnimatedModule = useSingleOpBatching
         'addListener', // 20
         'removeListener', // 21
       ];
-      return apis.reduce(
-        (acc, functionName, i) => {
-          // These indices need to be kept in sync with the indices in native (see NativeAnimatedModule in Java, or the equivalent for any other native platform).
-          // $FlowFixMe[prop-missing]
-          acc[functionName] = i + 1;
-          return acc;
-        },
-        {
-          ...null,
-        },
-      );
+      return apis.reduce((acc, functionName, i) => {
+        // These indices need to be kept in sync with the indices in native (see NativeAnimatedModule in Java, or the equivalent for any other native platform).
+        // $FlowFixMe[prop-missing]
+        acc[functionName] = i + 1;
+        return acc;
+      }, {});
     })(): $FlowFixMe)
   : NativeAnimatedModule;
 

Libraries/Components/TextInput/TextInput.js

@@ -986,7 +986,7 @@ function InternalTextInput(props: Props): React.Node {
   // that the update should be ignored and we should stick with the value
   // that we have in JS.
   useLayoutEffect(() => {
-    const nativeUpdate: {text?: string, selection?: Selection} = {...null};
+    const nativeUpdate: {text?: string, selection?: Selection} = {};
 
     if (lastNativeText !== props.value && typeof props.value === 'string') {
       nativeUpdate.text = props.value;

Libraries/Core/setUpPerformance.js

@@ -11,7 +11,7 @@
 'use strict';
 
 if (!global.performance) {
-  global.performance = ({...null}: {now?: () => number});
+  global.performance = ({}: {now?: () => number});
 }
 
 /**

Libraries/Utilities/__tests__/stringifySafe-test.js

@@ -33,7 +33,7 @@ describe('stringifySafe', () => {
   });
 
   it('stringifySafe stringifies circular objects with toString', () => {
-    const arg: {arg?: {...}} = {...null};
+    const arg: {arg?: {...}} = {};
     arg.arg = arg;
     const result = stringifySafe(arg);
     expect(result).toEqual('[object Object]');

Libraries/WebSocket/WebSocket.js

@@ -101,7 +101,7 @@ class WebSocket extends (EventTarget(...WEBSOCKET_EVENTS): any) {
       protocols = [protocols];
     }
 
-    const {headers = {}, ...unrecognized} = options || {...null};
+    const {headers = {}, ...unrecognized} = options || {};
 
     // Preserve deprecated backwards compatibility for the 'origin' option
     // $FlowFixMe[prop-missing]

packages/rn-tester/js/components/RNTesterPage.js

@@ -27,7 +27,7 @@ class RNTesterPage extends React.Component<Props> {
       automaticallyAdjustContentInsets?: boolean,
       keyboardShouldPersistTaps?: string,
       keyboardDismissMode?: string,
-    } = {...null};
+    } = {};
     if (this.props.noScroll) {
       ContentWrapper = ((View: any): React.ComponentType<any>);
     } else {

packages/rn-tester/js/examples/AnimatedGratuitousApp/AnExBobble.js

@@ -30,9 +30,7 @@ const BOBBLE_SPOTS = [...Array(NUM_BOBBLES)].map((_, i) => {
 class AnExBobble extends React.Component<Object, any> {
   constructor(props: Object) {
     super(props);
-    this.state = {
-      ...null,
-    };
+    this.state = {};
     // $FlowFixMe[prop-missing]
     this.state.bobbles = BOBBLE_SPOTS.map((_, i) => {
       return new Animated.ValueXY();
@@ -101,12 +99,7 @@ class AnExBobble extends React.Component<Object, any> {
       <View style={styles.bobbleContainer}>
         {this.state.bobbles.map((_, i) => {
           const j = this.state.bobbles.length - i - 1; // reverse so lead on top
-          const handlers =
-            j > 0
-              ? {
-                  ...null,
-                }
-              : this.state.bobbleResponder.panHandlers;
+          const handlers = j > 0 ? {} : this.state.bobbleResponder.panHandlers;
           return (
             <Animated.Image
               {...handlers}

packages/rn-tester/js/examples/Crash/CrashExample.js

@@ -26,7 +26,7 @@ exports.examples = [
         <Button
           title="JS crash"
           onPress={() => {
-            const a = {...null};
+            const a = {};
             // $FlowIgnore[prop-missing]
             // $FlowIgnore[incompatible-use]
             const b = a.w.q; // js crash here