Add iOS checkPermissions

Add a checkPermissions function allowing the app to determine what
notification permissions the user has granted. The function returns a
promise resolving to an object with permission info.

README.md

@@ -185,6 +185,16 @@ class App extends Component {
 
 When you have the device token, POST it to your server and register the device in your notifications provider (Amazon SNS, Azure, etc.).
 
+You can check if the user granted permissions by calling `checkPermissions()`:
+
+```javascript
+NotificationsIOS.checkPermissions().then((currentPermissions) => {
+    console.log('Badges enabled: ' + !!currentPermissions.badge);
+    console.log('Sounds enabled: ' + !!currentPermissions.sound);
+    console.log('Alerts enabled: ' + !!currentPermissions.alert);
+});
+```
+
 ### Android
 
 The React-Native code equivalent on Android is:

RNNotifications/RNNotifications.m

@@ -562,4 +562,14 @@ RCT_EXPORT_METHOD(isRegisteredForRemoteNotifications:(RCTPromiseResolveBlock)res
     resolve(@(ans));
 }
 
+RCT_EXPORT_METHOD(checkPermissions:(RCTPromiseResolveBlock) resolve
+                  reject:(RCTPromiseRejectBlock) reject) {
+    UIUserNotificationSettings *currentSettings = [[UIApplication sharedApplication] currentUserNotificationSettings];
+    resolve(@{
+              @"badge": @((currentSettings.types & UIUserNotificationTypeBadge) > 0),
+              @"sound": @((currentSettings.types & UIUserNotificationTypeSound) > 0),
+              @"alert": @((currentSettings.types & UIUserNotificationTypeAlert) > 0),
+              });
+}
+
 @end

index.ios.js

@@ -212,4 +212,8 @@ export default class NotificationsIOS {
   static isRegisteredForRemoteNotifications() {
     return NativeRNNotifications.isRegisteredForRemoteNotifications();
   }
+
+  static checkPermissions() {
+    return NativeRNNotifications.checkPermissions();
+  }
 }

test/index.ios.spec.js

@@ -68,7 +68,8 @@ describe("NotificationsIOS", () => {
             cancelLocalNotification: nativeCancelLocalNotification,
             cancelAllLocalNotifications: nativeCancelAllLocalNotifications,
             setBadgesCount: nativeSetBadgesCount,
-            isRegisteredForRemoteNotifications: nativeIsRegisteredForRemoteNotifications
+            isRegisteredForRemoteNotifications: nativeIsRegisteredForRemoteNotifications,
+            checkPermissions: nativeCheckPermissions,
           }
         },
         NativeAppEventEmitter: {
@@ -309,4 +310,12 @@ describe("NotificationsIOS", () => {
 
     });
   });
+
+  describe("Check permissions ", () => {
+    it("should call native check permissions", () => {
+      NotificationsIOS.checkPermissions();
+      expect(nativeCheckPermissions).to.have.been.calledWith();
+
+    });
+  });
 });