Generates empty folders

[p0ria]

I use this library inside my nest.js service.
Collection folders get created but they are all empty.
This is my code:

`var backup = require('mongodb-backup');
import { Injectable, Logger } from "@nestjs/common";

@Injectable()
export class BackupDbService {
private readonly logger = new Logger(BackupDbService.name);
mongoUrl = 'mongodb://localhost:27017/admin';

backupDb() {
    try {
        backup({
            uri: this.mongoUrl, // mongodb://<dbuser>:<dbpassword>@<dbdomain>.mongolab.com:<dbport>/<dbdatabase>
            collections: ['rates'],
            root: 'db',
            callback: function(err) {
                if (err) {
                  console.error(err);
                } else {
                  console.log('finish');
                }
              }
          });
    } catch (err) {
        this.logger.error(err);
    }
}

} `

[lihaibh]

@p0ria
I think i know what is the problem it one of the bugs of this library.
In my organisation we had a collection that contains documents with sensitive property keys such as:
person.fullname
Mongodb cant handle insertion of documents with properties that contains the dot character.
Unfortunately even if 1 document has an issue the insertion of the whole collection fails and you wont receive any error.

Ive created my own version of MongoDB backup and restore library you can take a look at my solution:
https://github.com/lihaibh/mongodb-snapshot/blob/83b12d377a1ec387f0bcf121b294cdd45504ac76/src/connectors/MongoDBDuplexConnector.ts#L258

BTW it doesn't create any "side effect" files like a directory for creating the backup.
you can try using it and i will help you.

[OlivierChirouze]

See #27 (comment) for a final solution