Creating a READSTREAM in GFS is throwing an error, does not seem catchable

Question

I am setting up an up/download and have used several resources. I need to be able to store the "files" in the Mongo datastore and then read them back out. I was able to upload, but downloading is through an error when I try to instantiate the createReadStream.

I have over come most of the other errors in the original code. Here is my Package.json:

{
  "name": "downloadtest",
  "version": "2.3.0",
  "license": "MIT",
  "scripts": {
  },
  "engines": {
    "node": "6.11.1",
    "npm": "3.10.9"
  },
  "private": true,
  "dependencies": {
    "body-parser": "^1.19.0",
    "core-js": "3.1.3",
    "express": "^4.17.1",
    "gridfs-stream": "^1.1.1",
    "mongoose": "^5.6.7",
    "mongoose-unique-validator": "^2.0.3",
    "multer": "^1.4.2",
    "multer-gridfs-storage": "^3.3.0",
    "path": "^0.12.7",
  },
  "devDependencies": {
  }
}

Here is the code that is throwing the error:

let express = require('express'); 
let app = express(); 
let bodyParser = require('body-parser');
let mongoose = require('mongoose');
mongoose.connect(mongoURI, { useNewUrlParser: true });
let conn =  mongoose.connection;
let multer = require('multer');
let GridFsStorage = require('multer-gridfs-storage');
let Grid = require('gridfs-stream');
Grid.mongo = mongoose.mongo;
let gfs = Grid(conn, mongoURI);
let port = 3000;

// Setting up the root route
app.get('/', (req, res) => {
    res.send('Welcome to the express server');
});

// Allows cross-origin domains to access this API
app.use((req, res, next) => {
    res.append('Access-Control-Allow-Origin' , 'http://localhost:4200');
    res.append('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.append("Access-Control-Allow-Headers", "Origin, Accept,Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");
    res.append('Access-Control-Allow-Credentials', true);
    next();
});

// BodyParser middleware
app.use(bodyParser.json());

// Setting up the storage element
let storage = GridFsStorage({
    gfs : gfs,
    url: mongoURI,
    options: {
        useNewUrlParser: true
        },
    filename: (req, file, cb) => {
        let date = Date.now();
        // The way you want to store your file in database
        cb(null, file.fieldname + '-' + date + '.'); 
    },

    // Additional Meta-data that you want to store
    metadata: function(req, file, cb) {
        cb(null, { originalname: file.originalname });
    },
    root: 'fs', //root name for collection to store files into
    curCol: 'fs'
});

// Multer configuration for single file uploads
let upload = multer({
    storage: storage
}).single('file');

// Route for file upload
app.post('/upload', (req, res) => {
    upload(req,res, (err) => {
        if(err){
             res.json({error_code:1,err_desc:err});
             return;
        }
        res.json({error_code:0, error_desc: null, file_uploaded: true});
    });
});

// Downloading a single file
app.get('/image/:filename', (req, res) => {
    console.log('Searching for: '+ req.params.filename);
    gfs.collection('fs'); //set collection name to lookup into

    /** First check if file exists */
    gfs.files.find({filename: req.params.filename}).toArray(function(err, files){
        if(!files || files.length === 0){
            return res.status(404).json({
                responseCode: 1,
                responseMessage: "error"
            });
        }
        // create read stream
        console.log('Found: ' + files[0].filename)
        // console.dir(gfs);
        console.dir(files[0])
        var readstream = gfs.createReadStream({
            filename: files[0].filename,
            root: "fs"
        });
        // // set the proper content type 
        // res.set('Content-Type', files[0].contentType)
        // // Return response
        // return readstream.pipe(res);
    });
});

app.listen(port, (req, res) => {
    console.log("Server started on port: " + port);
});

Finally, here is the error being thrown:

Server started on port: 3000
Searching for: d47e793f3f5492b4e55869d167a471f5_imageThumb.png
Found: d47e793f3f5492b4e55869d167a471f5_imageThumb.png
{ _id:
   ObjectID {
     _bsontype: 'ObjectID',
     id:
      Buffer [Uint8Array] [ 90, 104, 195, 29, 197, 30, 94, 0, 20, 99, 208, 206 ] },
  filename: 'd47e793f3f5492b4e55869d167a471f5_imageThumb.png',
  contentType: 'binary/octet-stream',
  length: 13031,
  chunkSize: 261120,
  uploadDate: 2018-01-24T17:32:14.048Z,
  aliases: null,
  metadata: null,
  md5: '5b314153a6bb0004329ccd1fcf8e037e' }
C:\Users\user\Desktop\downloadtest\node_modules\mongodb\lib\utils.js:132
      throw err;
      ^

TypeError: grid.mongo.ObjectID is not a constructor

I've found a couple of references, but nothing seems to relate. To help troubleshoot, I've put in a couple of console logs and a DIR. I am hitting the DB, I am getting the document.. I just cannot start the read stream.

Answer 1

I found the answer myself, and it was to do with versions and trying to use older models. I found another example that is working. I still need to optimize it.