$rename throws cast error

[klimashkin]

Hello!
When I try to do simple $rename update I get "Cast to number error".
Photo.update({r2: 167}, {$rename: {r2: 'r1'}}, {multi: true})

But if I do this through Model.collection.update or through mongo console all ok.
Photo.collection.update({r2: 167}, {$rename: {r2: 'r1'}}, {multi: true})

[jrvidal]

Apparently, Query.prototype._castUpdate casts the new field name to the corresponding type for $rename queries. Here is a simple test case:

var mongoose = require('mongoose'),

    User = mongoose.model('User', new mongoose.Schema({
        cool: Boolean
    }));

User.update({}, {
    $rename: {
        cool: 'awesome'
    }
}, function (err) {
    console.log(err.stack);
});

It failed for me in 3.8.25:

MongoError: The 'to' field for $rename must be a string: cool: true
    at Object.toError (/test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/utils.js:114:11)
    at /test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/collection/core.js:577:27
    at /test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:1195:7
    at /test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:1903:9
    at Server.Base._callHandler (/test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/base.js:453:41)
    at /test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:487:18
    at MongoReply.parseBody (/test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/responses/mongo_reply.js:68:5)
    at null.<anonymous> (/test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:445:20)
    at emit (events.js:95:17)
    at null.<anonymous> (/test_folder/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:207:13)

[sitegui]

It also seems to fail in [email protected]

Order.update({
    ETA: {
        $ne: null
    }
}, {
    $rename: {
        ETA: 'deliveryETA'
    }
}, {
    multi: true
}, done)

CastError: Cast to date failed for value "deliveryETA" at path "ETA"
    at SchemaDate.cast (node_modules\mongoose\lib\schema\date.js:232:9)
    at SchemaDate.castForQuery (node_modules\mongoose\lib\schema\date.js:277:17)
    at Query._castUpdateVal (node_modules\mongoose\lib\query.js:2241:17)
    at Query._walkUpdatePath (node_modules\mongoose\lib\query.js:2190:25)
    at Query._castUpdate (node_modules\mongoose\lib\query.js:2075:23)
    at Query.update (node_modules\mongoose\lib\query.js:1916:22)
    at Function.update (node_modules\mongoose\lib\model.js:1730:13)

Using Order.collection.update() works.

Is this intended? If yes, mongoose may want to warn about this in the docs.