Adds ability to update a subscription (#2935)

* Adds ability to update a subscription

* Adds unsubscribe to the RequestSchema, makes sure to not fire unsubscribe to the client when updating

* Fix failing tests

* More extensive tests

* fix annotation

src/LiveQuery/ParseLiveQueryServer.js

@@ -257,6 +257,9 @@ class ParseLiveQueryServer {
         case 'subscribe':
           this._handleSubscribe(parseWebsocket, request);
           break;
+        case 'update':
+          this._handleUpdateSubscription(parseWebsocket, request);
+          break;
         case 'unsubscribe':
           this._handleUnsubscribe(parseWebsocket, request);
           break;
@@ -471,7 +474,12 @@ class ParseLiveQueryServer {
     logger.verbose('Current client number: %d', this.clients.size);
   }
 
-  _handleUnsubscribe(parseWebsocket: any, request: any): any {
+  _handleUpdateSubscription(parseWebsocket: any, request: any): any {
+    this._handleUnsubscribe(parseWebsocket, request, false);
+    this._handleSubscribe(parseWebsocket, request);
+  }
+
+  _handleUnsubscribe(parseWebsocket: any, request: any, notifyClient: bool = true): any {
     // If we can not find this client, return error to client
     if (!parseWebsocket.hasOwnProperty('clientId')) {
       Client.pushError(parseWebsocket, 2, 'Can not find this client, make sure you connect to server before unsubscribing');
@@ -510,6 +518,10 @@ class ParseLiveQueryServer {
     if (classSubscriptions.size === 0) {
       this.subscriptions.delete(className);
     }
+    
+    if (!notifyClient) {
+      return;
+    }
 
     client.pushUnsubscribe(request.requestId);
 

src/LiveQuery/RequestSchema.js

@@ -4,7 +4,7 @@ let general = {
   'properties': {
     'op': {
       'type': 'string',
-      'enum': ['connect', 'subscribe', 'unsubscribe']
+      'enum': ['connect', 'subscribe', 'unsubscribe', 'update']
     },
   },
 };
@@ -78,6 +78,44 @@ let subscribe = {
   'additionalProperties': false
 };
 
+let update = {
+  'title': 'Update operation schema',
+  'type': 'object',
+  'properties': {
+    'op': 'update',
+    'requestId': {
+      'type': 'number'
+    },
+    'query': {
+      'title': 'Query field schema',
+      'type': 'object',
+      'properties': {
+        'className': {
+          'type': 'string'
+        },
+        'where': {
+          'type': 'object'
+        },
+        'fields': {
+          "type": "array",
+          "items": {
+              "type": "string"
+          },
+          "minItems": 1,
+          "uniqueItems": true
+        }
+      },
+      'required': ['where', 'className'],
+      'additionalProperties': false
+    },
+    'sessionToken': {
+      'type': 'string'
+    }
+  },
+  'required': ['op', 'requestId', 'query'],
+  'additionalProperties': false
+};
+
 let unsubscribe = {
   'title': 'Unsubscribe operation schema',
   'type': 'object',
@@ -95,6 +133,7 @@ let RequestSchema = {
   'general': general,
   'connect': connect,
   'subscribe': subscribe,
+  'update': update,
   'unsubscribe': unsubscribe
 }