Duplicate chunks on JSON response

[agaskell]

I came across this question on Stack Overflow and I was able to reproduce. If the response size is large enough the response body will be duplicated.

Code from the question:

Controller

// Get list of worlds
exports.index = function(req, res) {
  World.find(function (err, worlds) {
    if(err) { return handleError(res, err); }
    res.json(200, worlds);
  });
};

Model

'use strict';

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var WorldSchema = new Schema({
  name: String,
  info: String,
  active: Boolean,
  tiles: [Schema.Types.Mixed]
});

module.exports = mongoose.model('World', WorldSchema);

Seed

 var newWorld = new WorldModel({
                    _id: planet._objectId,
                    name: "SimDD World",
                    tiles : seed()
                });
                newWorld.save();

...

var seed = function () {
    var data = [];
    for (var i = 0; i < planet.HEIGHT; i++) {
        for (var j = 0; j < planet.WIDTH; j++) {
            data.push({
                coords:{
                    x:i,
                    y:j
                },
                type:'.'
            });
        }
    }
    return data;
}

[DaftMonk]

I tested this and was able reproduce it as well.

It appears to be caused by the compression middleware. Removing app.use(compression()); from the express config seems to fix this.

[meeDamian]

Maybe it's a good idea to report a bug here?

[DaftMonk]

Actually even though I was seeing duplicate responses in chrome and firefox, when I actually looked at the network tab, or used postman, or node request, I was only seeing one object. So I'm not sure this is a bug afterall.

[uniquer]

As @DaftMonk mentioned it is seen in browsers and not in postman. I checked the HTTP request headers and when I add 'Accept' Header as html in postman the same problem is seen in postman as well. So I believe the browsers are handled/rendered differently with Accept type with html