fix(query): upgrade mquery for readConcern() helper

Fix #6777

lib/query.js

@@ -1141,6 +1141,51 @@ Query.prototype.wtimeout = function wtimeout(ms) {
   return this;
 };
 
+/**
+ * Sets the readConcern option for the query.
+ *
+ * ####Example:
+ *
+ *     new Query().readConcern('local')
+ *     new Query().readConcern('l')  // same as local
+ *
+ *     new Query().readConcern('available')
+ *     new Query().readConcern('a')  // same as available
+ *
+ *     new Query().readConcern('majority')
+ *     new Query().readConcern('m')  // same as majority
+ *
+ *     new Query().readConcern('linearizable')
+ *     new Query().readConcern('lz') // same as linearizable
+ *
+ *     new Query().readConcern('snapshot')
+ *     new Query().readConcern('s')  // same as snapshot
+ *
+ *
+ * ####Read Concern Level:
+ *
+ *     local         MongoDB 3.2+ The query returns from the instance with no guarantee guarantee that the data has been written to a majority of the replica set members (i.e. may be rolled back).
+ *     available     MongoDB 3.6+ The query returns from the instance with no guarantee guarantee that the data has been written to a majority of the replica set members (i.e. may be rolled back).
+ *     majority      MongoDB 3.2+ The query returns the data that has been acknowledged by a majority of the replica set members. The documents returned by the read operation are durable, even in the event of failure.
+ *     linearizable  MongoDB 3.4+ The query returns data that reflects all successful majority-acknowledged writes that completed prior to the start of the read operation. The query may wait for concurrently executing writes to propagate to a majority of replica set members before returning results.
+ *     snapshot      MongoDB 4.0+ Only available for operations within multi-document transactions. Upon transaction commit with write concern "majority", the transaction operations are guaranteed to have read from a snapshot of majority-committed data.
+ *
+ * Aliases
+ *
+ *     l   local
+ *     a   available
+ *     m   majority
+ *     lz  linearizable
+ *     s   snapshot
+ *
+ * Read more about how to use read concern [here](https://docs.mongodb.com/manual/reference/read-concern/).
+ *
+ * @param {String} level one of the listed read concern level or their aliases
+ * @see mongodb https://docs.mongodb.com/manual/reference/read-concern/
+ * @return {Query} this
+ * @api public
+ */
+
 /**
  * Merges another Query or conditions object into this one.
  *

package.json

@@ -27,7 +27,7 @@
     "mongodb-core": "3.1.0",
     "mongoose-legacy-pluralize": "1.0.2",
     "mpath": "0.4.1",
-    "mquery": "3.0.0",
+    "mquery": "3.1.1",
     "ms": "2.0.0",
     "regexp-clone": "0.0.1",
     "sliced": "1.0.1"

test/query.test.js

@@ -749,9 +749,9 @@ describe('Query', function() {
 
       if (typeof global.Map !== 'undefined') {
         query = new Query({}, {}, null, p1.collection);
-        query.sort(new global.Map().set('a', 1).set('b', 2));
+        query.sort(new global.Map().set('a', 1).set('b', 1));
         assert.equal(query.options.sort.get('a'), 1);
-        assert.equal(query.options.sort.get('b'), 2);
+        assert.equal(query.options.sort.get('b'), 1);
       }
 
       query = new Query({}, {}, null, p1.collection);