create + use adapter count instead of collection count

Author: drew-gross

spec/InstallationsRouter.spec.js

@@ -123,11 +123,9 @@ describe('InstallationsRouter', () => {
 
     var router = new InstallationsRouter();
     rest.create(config, auth.nobody(config), '_Installation', androidDeviceRequest)
-        .then(() => {
-          return rest.create(config, auth.nobody(config), '_Installation', iosDeviceRequest);
-        }).then(() => {
-      return router.handleFind(request);
-    }).then((res) => {
+    .then(() => rest.create(config, auth.nobody(config), '_Installation', iosDeviceRequest))
+    .then(() => router.handleFind(request))
+    .then((res) => {
       var response = res.response;
       expect(response.results.length).toEqual(2);
       expect(response.count).toEqual(2);

src/Adapters/Storage/Mongo/MongoStorageAdapter.js

@@ -205,6 +205,12 @@ export class MongoStorageAdapter {
     .then(objects => objects.map(object => transform.mongoObjectToParseObject(className, object, schema)));
   }
 
+  // Executs a count.
+  count(className, query, mongoOptions) {
+    return this.adaptiveCollection(className)
+    .then(collection => collection.count(query, mongoOptions));
+  }
+
   get transform() {
     return transform;
   }

src/Controllers/DatabaseController.js

@@ -699,7 +699,7 @@ DatabaseController.prototype.find = function(className, query, {
         if (count) {
           let mongoWhere = this.transform.transformWhere(className, query, schema);
           delete mongoOptions.limit;
-          return collection.count(mongoWhere, mongoOptions);
+          return this.adapter.count(className, mongoWhere, mongoOptions);
         } else {
           return this.adapter.find(className, query, mongoOptions, schema)
           .then(objects => objects.map(object => filterSensitiveData(isMaster, aclGroup, className, object)));