[ReactNative] Flow and doc formatting for NetInfo

Libraries/Network/NetInfo.js

@@ -21,18 +21,25 @@ type ChangeEventName = $Enum<{
   change: string;
 }>;
 
+type ReachabilityStateIOS = $Enum<{
+  cell: string;
+  none: string;
+  unknown: string;
+  wifi: string;
+}>;
+
 
 /**
  * NetInfo exposes info about online/offline status
  *
- * == iOS Reachability
+ * ### reachabilityIOS
  *
  * Asyncronously determine if the device is online and on a cellular network.
  *
- * - "none" - device is offline
+ * - `none` - device is offline
- * - "wifi" - device is online and connected via wifi, or is the iOS simulator
+ * - `wifi` - device is online and connected via wifi, or is the iOS simulator
- * - "cell" - device is connected via Edge, 3G, WiMax, or LTE
+ * - `cell` - device is connected via Edge, 3G, WiMax, or LTE
- * - "unknown" - error case and the network status is unknown
+ * - `unknown` - error case and the network status is unknown
  *
  * ```
  * NetInfo.reachabilityIOS.fetch().done((reach) => {
@@ -50,11 +57,37 @@ type ChangeEventName = $Enum<{
  *   handleFirstReachabilityChange
  * );
  * ```
+ *
+ * ### isConnected
+ *
+ * Available on all platforms. Asyncronously fetch a boolean to determine
+ * internet connectivity.
+ *
+ * ```
+ * NetInfo.isConnected.fetch().done((isConnected) => {
+ *   console.log('First, is ' + (isConnected ? 'online' : 'offline'));
+ * });
+ * function handleFirstConnectivityChange(isConnected) {
+ *   console.log('Then, is ' + (isConnected ? 'online' : 'offline'));
+ *   NetInfo.isConnected.removeEventListener(
+ *     'change',
+ *     handleFirstConnectivityChange
+ *   );
+ * }
+ * NetInfo.isConnected.addEventListener(
+ *   'change',
+ *   handleFirstConnectivityChange
+ * );
+ * ```
  */
 
 var NetInfo = {};
 
 if (RCTReachability) {
+
+  // RCTReachability is exposed, so this is an iOS-like environment and we will
+  // expose reachabilityIOS
+
   var _reachabilitySubscriptions = {};
 
   NetInfo.reachabilityIOS = {
@@ -84,7 +117,7 @@ if (RCTReachability) {
     fetch: function(): Promise {
       return new Promise((resolve, reject) => {
         RCTReachability.getCurrentReachability(
-          (resp) => {
+          function(resp) {
             resolve(resp.network_reachability);
           },
           reject
@@ -93,53 +126,42 @@ if (RCTReachability) {
     },
   };
 
-  /**
-   *
-   * == NetInfo.isConnected
-   *
-   * Available on all platforms. Asyncronously fetch a boolean to determine
-   * internet connectivity.
-   *
-   * ```
-   * NetInfo.isConnected.fetch().done((isConnected) => {
-   *   console.log('First, is ' + (isConnected ? 'online' : 'offline'));
-   * });
-   * function handleFirstConnectivityChange(isConnected) {
-   *   console.log('Then, is ' + (isConnected ? 'online' : 'offline'));
-   *   NetInfo.isConnected.removeEventListener(
-   *     'change',
-   *     handleFirstConnectivityChange
-   *   );
-   * }
-   * NetInfo.isConnected.addEventListener(
-   *   'change',
-   *   handleFirstConnectivityChange
-   * );
-   * ```
-   *
-   */
   var _isConnectedSubscriptions = {};
+
+  var _iosReachabilityIsConnected = function(
+    reachability: ReachabilityStateIOS
+  ): bool {
+    return reachability !== 'none' &&
+      reachability !== 'unknown';
+  };
+
   NetInfo.isConnected = {
     addEventListener: function (
       eventName: ChangeEventName,
       handler: Function
     ): void {
       _isConnectedSubscriptions[handler] = (reachability) => {
-        handler(reachability !== 'none');
+        handler(_iosReachabilityIsConnected(reachability));
       };
-      NetInfo.reachabilityIOS.addEventListener(eventName, _isConnectedSubscriptions[handler]);
+      NetInfo.reachabilityIOS.addEventListener(
+        eventName,
+        _isConnectedSubscriptions[handler]
+      );
     },
 
     removeEventListener: function(
       eventName: ChangeEventName,
       handler: Function
     ): void {
-      NetInfo.reachabilityIOS.removeEventListener(eventName, _isConnectedSubscriptions[handler]);
+      NetInfo.reachabilityIOS.removeEventListener(
+        eventName,
+        _isConnectedSubscriptions[handler]
+      );
     },
 
     fetch: function(): Promise {
       return NetInfo.reachabilityIOS.fetch().then(
-        (reachability) => reachability !== 'none'
+        (reachability) => _iosReachabilityIsConnected(reachability)
       );
     },
   };