Gridfs-stream createReadStream

[crossSulation]

const readStream =this._gridfs.createReadStream(file.filename);
readStream.on('error',(error)=>{
resp.send('No Image from that title!');
resp.end();
})
readStream.pipe(resp);

code like these, when only set up the readStream with filename, it will throw error ,
this._store = new grid.mongo.GridStore(grid.db, this.id || new grid.mongo.ObjectID(), this.name, this.mode, options);

when I debug, I found grid.mongo.ObjectID is undefined

[crossSulation]

By the way, i am using mongoose

[crossSulation]

sorry, my fault, actually, when construct the GridFSStream, the second argument should the the instance of mongodb

this._gridfs = GridFSStream(this._conn.connection.db,conn.mongo)

[crossSulation]

Made a mistake, actually ,it works, when construct the GRIDFSStream, the second argument should be
the instance of moogodb

this._gridfs = GridFSStream(this._conn.connection.db,conn.mongo)