Add minimal Flow types to remaining files under Libraries/

Summary:
Adds `flow` annotation, and/or adds minimal Flow types to remaining files under `packages/react-native/Libraries/`. As of this diff, 100% of this directory is now parsable by `flow-api-translator` and covered by `public-api-test`.

Changelog: [Internal]

Differential Revision: D60377082

packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.js

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
 'use strict';

packages/react-native/Libraries/Components/Touchable/BoundingDimensions.js

@@ -5,9 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
 'use strict';
+
 import PooledClass from './PooledClass';
 
 const twoArgumentPooler = PooledClass.twoArgumentPooler;
@@ -19,11 +21,14 @@ const twoArgumentPooler = PooledClass.twoArgumentPooler;
  * @param {number} height Height of bounding rectangle.
  * @constructor BoundingDimensions
  */
-function BoundingDimensions(width, height) {
+// $FlowFixMe[missing-this-annot]
+function BoundingDimensions(width: number, height: number) {
   this.width = width;
   this.height = height;
 }
 
+// $FlowFixMe[prop-missing]
+// $FlowFixMe[missing-this-annot]
 BoundingDimensions.prototype.destructor = function () {
   this.width = null;
   this.height = null;
@@ -33,13 +38,16 @@ BoundingDimensions.prototype.destructor = function () {
  * @param {HTMLElement} element Element to return `BoundingDimensions` for.
  * @return {BoundingDimensions} Bounding dimensions of `element`.
  */
-BoundingDimensions.getPooledFromElement = function (element) {
+BoundingDimensions.getPooledFromElement = function (
+  element: HTMLElement,
+): typeof BoundingDimensions {
+  // $FlowFixMe[prop-missing]
   return BoundingDimensions.getPooled(
     element.offsetWidth,
     element.offsetHeight,
   );
 };
 
-PooledClass.addPoolingTo(BoundingDimensions, twoArgumentPooler);
+PooledClass.addPoolingTo(BoundingDimensions as $FlowFixMe, twoArgumentPooler);
 
 module.exports = BoundingDimensions;

packages/react-native/Libraries/Components/Touchable/Position.js

@@ -5,9 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
 'use strict';
+
 import PooledClass from './PooledClass';
 
 const twoArgumentPooler = PooledClass.twoArgumentPooler;
@@ -20,16 +22,19 @@ const twoArgumentPooler = PooledClass.twoArgumentPooler;
  * @param {number} windowStartKey Key that window starts at.
  * @param {number} windowEndKey Key that window ends at.
  */
-function Position(left, top) {
+// $FlowFixMe[missing-this-annot]
+function Position(left: number, top: number) {
   this.left = left;
   this.top = top;
 }
 
+// $FlowFixMe[prop-missing]
+// $FlowFixMe[missing-this-annot]
 Position.prototype.destructor = function () {
   this.left = null;
   this.top = null;
 };
 
-PooledClass.addPoolingTo(Position, twoArgumentPooler);
+PooledClass.addPoolingTo(Position as $FlowFixMe, twoArgumentPooler);
 
 module.exports = Position;

packages/react-native/Libraries/Interaction/TouchHistoryMath.js

@@ -5,8 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
+// $FlowFixMe[definition-cycle]
+// $FlowFixMe[recursive-definition]
 const TouchHistoryMath = {
   /**
    * This code is optimized and not intended to look beautiful. This allows
@@ -25,11 +28,11 @@ const TouchHistoryMath = {
    * @return {number} value of centroid in specified dimension.
    */
   centroidDimension: function (
-    touchHistory,
-    touchesChangedAfter,
-    isXAxis,
-    ofCurrent,
-  ) {
+    touchHistory: TouchHistoryMath,
+    touchesChangedAfter: number,
+    isXAxis: boolean,
+    ofCurrent: boolean,
+  ): number {
     const touchBank = touchHistory.touchBank;
     let total = 0;
     let count = 0;
@@ -82,9 +85,9 @@ const TouchHistoryMath = {
   },
 
   currentCentroidXOfTouchesChangedAfter: function (
-    touchHistory,
-    touchesChangedAfter,
-  ) {
+    touchHistory: TouchHistoryMath,
+    touchesChangedAfter: number,
+  ): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       touchesChangedAfter,
@@ -94,9 +97,9 @@ const TouchHistoryMath = {
   },
 
   currentCentroidYOfTouchesChangedAfter: function (
-    touchHistory,
-    touchesChangedAfter,
-  ) {
+    touchHistory: TouchHistoryMath,
+    touchesChangedAfter: number,
+  ): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       touchesChangedAfter,
@@ -106,9 +109,9 @@ const TouchHistoryMath = {
   },
 
   previousCentroidXOfTouchesChangedAfter: function (
-    touchHistory,
-    touchesChangedAfter,
-  ) {
+    touchHistory: TouchHistoryMath,
+    touchesChangedAfter: number,
+  ): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       touchesChangedAfter,
@@ -118,9 +121,9 @@ const TouchHistoryMath = {
   },
 
   previousCentroidYOfTouchesChangedAfter: function (
-    touchHistory,
-    touchesChangedAfter,
-  ) {
+    touchHistory: TouchHistoryMath,
+    touchesChangedAfter: number,
+  ): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       touchesChangedAfter,
@@ -129,7 +132,7 @@ const TouchHistoryMath = {
     );
   },
 
-  currentCentroidX: function (touchHistory) {
+  currentCentroidX: function (touchHistory: TouchHistoryMath): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       0, // touchesChangedAfter
@@ -138,7 +141,7 @@ const TouchHistoryMath = {
     );
   },
 
-  currentCentroidY: function (touchHistory) {
+  currentCentroidY: function (touchHistory: TouchHistoryMath): number {
     return TouchHistoryMath.centroidDimension(
       touchHistory,
       0, // touchesChangedAfter

packages/react-native/Libraries/Network/XHRInterceptor.js

@@ -5,20 +5,57 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
 'use strict';
 
 const XMLHttpRequest = require('./XMLHttpRequest');
+// $FlowFixMe[method-unbinding]
 const originalXHROpen = XMLHttpRequest.prototype.open;
+// $FlowFixMe[method-unbinding]
 const originalXHRSend = XMLHttpRequest.prototype.send;
+// $FlowFixMe[method-unbinding]
 const originalXHRSetRequestHeader = XMLHttpRequest.prototype.setRequestHeader;
 
-let openCallback;
-let sendCallback;
-let requestHeaderCallback;
-let headerReceivedCallback;
-let responseCallback;
+type XHRInterceptorOpenCallback = (
+  method: string,
+  url: string,
+  request: XMLHttpRequest,
+) => void;
+
+type XHRInterceptorSendCallback = (
+  data: string,
+  request: XMLHttpRequest,
+) => void;
+
+type XHRInterceptorRequestHeaderCallback = (
+  header: string,
+  value: string,
+  request: XMLHttpRequest,
+) => void;
+
+type XHRInterceptorHeaderReceivedCallback = (
+  responseContentType: string | void,
+  responseSize: number | void,
+  allHeaders: string,
+  request: XMLHttpRequest,
+) => void;
+
+type XHRInterceptorResponseCallback = (
+  status: number,
+  timeout: number,
+  response: string,
+  responseURL: string,
+  responseType: string,
+  request: XMLHttpRequest,
+) => void;
+
+let openCallback: XHRInterceptorOpenCallback | null;
+let sendCallback: XHRInterceptorSendCallback | null;
+let requestHeaderCallback: XHRInterceptorRequestHeaderCallback | null;
+let headerReceivedCallback: XHRInterceptorHeaderReceivedCallback | null;
+let responseCallback: XHRInterceptorResponseCallback | null;
 
 let isInterceptorEnabled = false;
 
@@ -33,39 +70,39 @@ const XHRInterceptor = {
   /**
    * Invoked before XMLHttpRequest.open(...) is called.
    */
-  setOpenCallback(callback) {
+  setOpenCallback(callback: XHRInterceptorOpenCallback) {
     openCallback = callback;
   },
 
   /**
    * Invoked before XMLHttpRequest.send(...) is called.
    */
-  setSendCallback(callback) {
+  setSendCallback(callback: XHRInterceptorSendCallback) {
     sendCallback = callback;
   },
 
   /**
    * Invoked after xhr's readyState becomes xhr.HEADERS_RECEIVED.
    */
-  setHeaderReceivedCallback(callback) {
+  setHeaderReceivedCallback(callback: XHRInterceptorHeaderReceivedCallback) {
     headerReceivedCallback = callback;
   },
 
   /**
    * Invoked after xhr's readyState becomes xhr.DONE.
    */
-  setResponseCallback(callback) {
+  setResponseCallback(callback: XHRInterceptorResponseCallback) {
     responseCallback = callback;
   },
 
   /**
    * Invoked before XMLHttpRequest.setRequestHeader(...) is called.
    */
-  setRequestHeaderCallback(callback) {
+  setRequestHeaderCallback(callback: XHRInterceptorRequestHeaderCallback) {
     requestHeaderCallback = callback;
   },
 
-  isInterceptorEnabled() {
+  isInterceptorEnabled(): boolean {
     return isInterceptorEnabled;
   },
 
@@ -75,7 +112,9 @@ const XHRInterceptor = {
     }
     // Override `open` method for all XHR requests to intercept the request
     // method and url, then pass them through the `openCallback`.
-    XMLHttpRequest.prototype.open = function (method, url) {
+    // $FlowFixMe[cannot-write]
+    // $FlowFixMe[missing-this-annot]
+    XMLHttpRequest.prototype.open = function (method: string, url: string) {
       if (openCallback) {
         openCallback(method, url, this);
       }
@@ -84,7 +123,12 @@ const XHRInterceptor = {
 
     // Override `setRequestHeader` method for all XHR requests to intercept
     // the request headers, then pass them through the `requestHeaderCallback`.
-    XMLHttpRequest.prototype.setRequestHeader = function (header, value) {
+    // $FlowFixMe[cannot-write]
+    // $FlowFixMe[missing-this-annot]
+    XMLHttpRequest.prototype.setRequestHeader = function (
+      header: string,
+      value: string,
+    ) {
       if (requestHeaderCallback) {
         requestHeaderCallback(header, value, this);
       }
@@ -93,7 +137,9 @@ const XHRInterceptor = {
 
     // Override `send` method of all XHR requests to intercept the data sent,
     // register listeners to intercept the response, and invoke the callbacks.
-    XMLHttpRequest.prototype.send = function (data) {
+    // $FlowFixMe[cannot-write]
+    // $FlowFixMe[missing-this-annot]
+    XMLHttpRequest.prototype.send = function (data: string) {
       if (sendCallback) {
         sendCallback(data, this);
       }
@@ -151,8 +197,11 @@ const XHRInterceptor = {
       return;
     }
     isInterceptorEnabled = false;
+    // $FlowFixMe[cannot-write]
     XMLHttpRequest.prototype.send = originalXHRSend;
+    // $FlowFixMe[cannot-write]
     XMLHttpRequest.prototype.open = originalXHROpen;
+    // $FlowFixMe[cannot-write]
     XMLHttpRequest.prototype.setRequestHeader = originalXHRSetRequestHeader;
     responseCallback = null;
     openCallback = null;

packages/react-native/Libraries/WebSocket/WebSocketEvent.js

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
+ * @flow strict-local
  */
 
 'use strict';
@@ -18,7 +19,9 @@
  * In case of "message", the `data` property contains the incoming data.
  */
 class WebSocketEvent {
-  constructor(type, eventInitDict) {
+  type: string;
+
+  constructor(type: string, eventInitDict: $FlowFixMe) {
     this.type = type.toString();
     Object.assign(this, eventInitDict);
   }