adds ability to set hint on Parse.Query #6288 (#6322)

* added hint to aggregate

* added support for hint in query

* added else clause to aggregate

* fixed tests

* updated tests

* Add tests and clean up

* Add support for explain

Co-authored-by: Diamond Lewis <findlewis@gmail.com>

src/Adapters/Storage/Mongo/MongoCollection.js

@@ -13,7 +13,10 @@ export default class MongoCollection {
   // none, then build the geoindex.
   // This could be improved a lot but it's not clear if that's a good
   // idea. Or even if this behavior is a good idea.
-  find(query, { skip, limit, sort, keys, maxTimeMS, readPreference } = {}) {
+  find(
+    query,
+    { skip, limit, sort, keys, maxTimeMS, readPreference, hint, explain } = {}
+  ) {
     // Support for Full Text Search - $text
     if (keys && keys.$score) {
       delete keys.$score;
@@ -26,6 +29,8 @@ export default class MongoCollection {
       keys,
       maxTimeMS,
       readPreference,
+      hint,
+      explain,
     }).catch(error => {
       // Check for "no geoindex" error
       if (
@@ -54,18 +59,24 @@ export default class MongoCollection {
               keys,
               maxTimeMS,
               readPreference,
+              hint,
+              explain,
             })
           )
       );
     });
   }
 
-  _rawFind(query, { skip, limit, sort, keys, maxTimeMS, readPreference } = {}) {
+  _rawFind(
+    query,
+    { skip, limit, sort, keys, maxTimeMS, readPreference, hint, explain } = {}
+  ) {
     let findOperation = this._mongoCollection.find(query, {
       skip,
       limit,
       sort,
       readPreference,
+      hint,
     });
 
     if (keys) {
@@ -76,10 +87,10 @@ export default class MongoCollection {
       findOperation = findOperation.maxTimeMS(maxTimeMS);
     }
 
-    return findOperation.toArray();
+    return explain ? findOperation.explain(explain) : findOperation.toArray();
   }
 
-  count(query, { skip, limit, sort, maxTimeMS, readPreference } = {}) {
+  count(query, { skip, limit, sort, maxTimeMS, readPreference, hint } = {}) {
     // If query is empty, then use estimatedDocumentCount instead.
     // This is due to countDocuments performing a scan,
     // which greatly increases execution time when being run on large collections.
@@ -96,6 +107,7 @@ export default class MongoCollection {
       sort,
       maxTimeMS,
       readPreference,
+      hint,
     });
 
     return countOperation;
@@ -105,9 +117,9 @@ export default class MongoCollection {
     return this._mongoCollection.distinct(field, query);
   }
 
-  aggregate(pipeline, { maxTimeMS, readPreference } = {}) {
+  aggregate(pipeline, { maxTimeMS, readPreference, hint, explain } = {}) {
     return this._mongoCollection
-      .aggregate(pipeline, { maxTimeMS, readPreference })
+      .aggregate(pipeline, { maxTimeMS, readPreference, hint, explain })
       .toArray();
   }
 

src/Adapters/Storage/Mongo/MongoStorageAdapter.js

@@ -620,7 +620,7 @@ export class MongoStorageAdapter implements StorageAdapter {
     className: string,
     schema: SchemaType,
     query: QueryType,
-    { skip, limit, sort, keys, readPreference }: QueryOptions
+    { skip, limit, sort, keys, readPreference, hint, explain }: QueryOptions
   ): Promise<any> {
     schema = convertParseSchemaToMongoSchema(schema);
     const mongoWhere = transformWhere(className, query, schema);
@@ -652,13 +652,18 @@ export class MongoStorageAdapter implements StorageAdapter {
           keys: mongoKeys,
           maxTimeMS: this._maxTimeMS,
           readPreference,
+          hint,
+          explain,
         })
       )
-      .then(objects =>
-        objects.map(object =>
+      .then(objects => {
+        if (explain) {
+          return objects;
+        }
+        return objects.map(object =>
           mongoObjectToParseObject(className, object, schema)
-        )
-      )
+        );
+      })
       .catch(err => this.handleError(err));
   }
 
@@ -712,7 +717,8 @@ export class MongoStorageAdapter implements StorageAdapter {
     className: string,
     schema: SchemaType,
     query: QueryType,
-    readPreference: ?string
+    readPreference: ?string,
+    hint: ?mixed
   ) {
     schema = convertParseSchemaToMongoSchema(schema);
     readPreference = this._parseReadPreference(readPreference);
@@ -721,6 +727,7 @@ export class MongoStorageAdapter implements StorageAdapter {
         collection.count(transformWhere(className, query, schema, true), {
           maxTimeMS: this._maxTimeMS,
           readPreference,
+          hint,
         })
       )
       .catch(err => this.handleError(err));
@@ -760,7 +767,9 @@ export class MongoStorageAdapter implements StorageAdapter {
     className: string,
     schema: any,
     pipeline: any,
-    readPreference: ?string
+    readPreference: ?string,
+    hint: ?mixed,
+    explain?: boolean
   ) {
     let isPointerField = false;
     pipeline = pipeline.map(stage => {
@@ -791,6 +800,8 @@ export class MongoStorageAdapter implements StorageAdapter {
         collection.aggregate(pipeline, {
           readPreference,
           maxTimeMS: this._maxTimeMS,
+          hint,
+          explain,
         })
       )
       .then(results => {

src/Adapters/Storage/StorageAdapter.js

@@ -14,6 +14,8 @@ export type QueryOptions = {
   distinct?: boolean,
   pipeline?: any,
   readPreference?: ?string,
+  hint?: ?mixed,
+  explain?: Boolean,
 };
 
 export type UpdateQueryOptions = {
@@ -92,7 +94,8 @@ export interface StorageAdapter {
     schema: SchemaType,
     query: QueryType,
     readPreference?: string,
-    estimate?: boolean
+    estimate?: boolean,
+    hint?: mixed
   ): Promise<number>;
   distinct(
     className: string,
@@ -104,7 +107,9 @@ export interface StorageAdapter {
     className: string,
     schema: any,
     pipeline: any,
-    readPreference: ?string
+    readPreference: ?string,
+    hint: ?mixed,
+    explain?: boolean
   ): Promise<any>;
   performInitialization(options: ?any): Promise<void>;