GridFS Unit testing with Mockgoose

Info

gridfs-stream ^1.1.1 mockgoose ^7.3.5 nodejs v8.11.2

Description

I am trying to write some unit tests that incorporate gridfs-stream and mockgoose. I have the database mocked out and the connection to gridfs set up as follows:

const mongoose = require('mongoose')
const Mockgoose = require('mockgoose').Mockgoose
const mockgoose = new Mockgoose(mongoose)

mockgoose.prepareStorage().then(function () {
    mongoose.connect(`mongodb://${process.env.DB_ADDRESS}/${process.env.DB_NAME}`)
})

const gridfs = require('gridfs-stream')(mockgoose.mongooseObj.connections[0], database.mongooseObj.mongo)

When inserting a file into the database by use of a stream:

let options = {
    mode: 'w',
    content_type: 'application/pdf',
    root: 'files',
    filename: 'test-file.pdf'
}
let wStream = gridfs.createWriteStream(options)

await (new Promise((resolve, reject) => {
    fs.createReadStream('./test/supportFiles/test.pdf')
        .on('error', (err) => {
            reject(err)
        })
        .on('end', () => {
            resolve()
        })
        .pipe(wStream)
}))

Content is found from the file with the rStream and the data has a length

.on('data', (data) => {
    // data has a length there it is a buffer returned
})

Problem

When attempting to retrieve the file from the database by use of the id of the file inserted, I am receiving an error that file with id 5bb62062ac13503388572732 not opened for writing. The file is retrieved from the database however the retrieved file has no length.

Error

GridReadStream {
  _readableState: 
   ReadableState {
     objectMode: false,
     highWaterMark: 16384,
     buffer: BufferList { head: null, tail: null, length: 0 },
     length: 0,
     pipes: null,
     pipesCount: 0,
     flowing: true,
     ended: false,
     endEmitted: false,
     reading: false,
     sync: true,
     needReadable: false,
     emittedReadable: false,
     readableListening: false,
     resumeScheduled: true,
     destroyed: false,
     defaultEncoding: 'utf8',
     awaitDrain: 0,
     readingMore: false,
     decoder: null,
     encoding: null },
  readable: true,
  domain: null,
  _events: { end: [Function], error: [Function], data: [Function] },
  _eventsCount: 3,
  _maxListeners: undefined,
  _opened: false,
  _opening: false,
  _closing: false,
  _end: false,
  _needToPush: false,
  _grid: 
   Grid {
     db: 
      NativeConnection {
        base: [Object],
        collections: [Object],
        models: [Object],
        config: [Object],
        replica: false,
        hosts: null,
        host: 'localhost',
        port: 27017,
        user: undefined,
        pass: undefined,
        name: 'mockgoose-temp-db-49d8417a-9bf0-43c4-b29e-87d820cfd437',
        options: [Object],
        otherDbs: [],
        states: [Object],
        _readyState: 1,
        _closeCalled: false,
        _hasOpened: true,
        _listening: false,
        _events: [Object],
        _eventsCount: 1,
        db: [Object] },
     mongo: 
      { [Function]
        MongoError: [Object],
        Admin: [Object],
        MongoClient: [Object],
        Db: [Object],
        Collection: [Object],
        Server: [Object],
        ReplSet: [Object],
        Mongos: [Object],
        ReadPreference: [Object],
        GridStore: [Object],
        Chunk: [Object],
        Logger: [Object],
        Cursor: [Object],
        GridFSBucket: [Object],
        CoreServer: [Object],
        CoreConnection: [Object],
        Binary: [Object],
        Code: [Object],
        Map: [Object],
        DBRef: [Object],
        Double: [Object],
        Int32: [Object],
        Long: [Object],
        MinKey: [Object],
        MaxKey: [Object],
        ObjectID: [Object],
        ObjectId: [Object],
        Symbol: [Object],
        Timestamp: [Object],
        BSONRegExp: [Object],
        Decimal128: [Object],
        connect: [Circular],
        instrument: [Function] },
     curCol: 'fs' },
  options: { _id: 5bb62062ac13503388572732, mode: 'r', root: 'files' },
  id: 5bb62062ac13503388572732,
  name: '',
  mode: 'r',
  _chunkSize: 261120,
  range: { startPos: 0, endPos: undefined },
  _currentPos: 0,
  _store: 
   GridStore {
     db: 
      NativeConnection {
        base: [Object],
        collections: [Object],
        models: [Object],
        config: [Object],
        replica: false,
        hosts: null,
        host: 'localhost',
        port: 27017,
        user: undefined,
        pass: undefined,
        name: 'mockgoose-temp-db-49d8417a-9bf0-43c4-b29e-87d820cfd437',
        options: [Object],
        otherDbs: [],
        states: [Object],
        _readyState: 1,
        _closeCalled: false,
        _hasOpened: true,
        _listening: false,
        _events: [Object],
        _eventsCount: 1,
        db: [Object] },
     referenceBy: 1,
     fileId: 5bb62062ac13503388572732,
     filename: '',
     mode: 'r',
     options: { _id: 5bb62062ac13503388572732, mode: 'r', root: 'files' },
     isOpen: false,
     root: 'files',
     position: 0,
     readPreference: 'primary',
     writeConcern: { w: 1 },
     internalChunkSize: 261120,
     promiseLibrary: [Function: Promise],
     chunkSize: [Getter/Setter],
     md5: [Getter],
     chunkNumber: [Getter] } }

Questions

Is gridfs-stream compatible with mockgoose or any form of mocking mongoose/mongodb? Is my configuration of gridfs-stream and/or mockgoose correct for this usage? Any help would be appreciated thanks.

aheckmann / gridfs-stream