Ex5: Insert. / Keep getting "AssertionError"

Ex 5 keeps failing with that error:

{ [AssertionError: { n: 1, ok: 1 } deepEqual { firstName: 'Jane', lastName: 'George' }]
  name: 'AssertionError',
  actual: { n: 1, ok: 1 },
  expected: { firstName: 'Jane', lastName: 'George' },
  operator: 'deepEqual',
  message: '{ n: 1, ok: 1 } deepEqual { firstName: \'Jane\', lastName: \'George\' }',
  generatedMessage: true }
✗ { n: 1, ok: 1 } deepEqual { firstName: 'Jane', lastName: 'George' }

My code:

var mongo = require('mongodb').MongoClient;

mongo.connect('mongodb://localhost:27017/learnyoumongo', function(err, db) {
    if(err) throw err;
    var collection = db.collection('docs');

    collection.insertOne({firstName: process.argv[2], lastName: process.argv[3]}, function(err, data) {
      if(err) throw err;

      data = JSON.stringify(data);
      console.log(data);
      db.close();
    });

});

Is it a bug or am I doing something wrong??

Thanks

[mdavidmorton]

I had the same problem. The issue was that the callback wasn’t returning the object I thought.

var doc = { firstName: process.argv[2], lastName: process.argv }

// ...
collection.insert(doc, function(err, data) {
    // error handling
    console.log(JSON.stringify(doc)); // <~ doc, not data
    db.close();
}

[sakthi17]

Seems the object returned by the insertOne callback has changed in version 3.x.

It gives an object containing various properties . Refer http://mongodb.github.io/node-mongodb-native/3.0/api/Collection.html#~insertOneWriteOpCallback

ops is the prop we are looking for. ops is an array of inserted doc objects. console.log( JSON.stringify( result.ops)) where result is the object returned from insertOne() callback.

Still the result wont match. Because of the extra _id property in our ops object. It gets added to every doc inserted by default . We can turn off this behaviour by setting forceServerObjectId == false in .insert() options collection.insertOne(doc , {forceServerObjectId : true}, callback )

There is one more thing to it. We do a stringify on ops which is an array containing inserted objects. But for the assert to work, we need the stringified version of the doc object inserted and not the array containing all the inserted docs. So get ops[0] which is the doc and then JSON-stringify it

Below is the final code where the solution gets passed :

var MongoClient = require('mongodb').MongoClient

var doc = {
        firstName : process.argv[2],
        lastName : process.argv[3]
}
var url = "mongodb://localhost:27017";
MongoClient.connect(url, function(err,client){
        if(err) throw err;
        var db = client.db("learnyoumongo");
        var collection = db.collection("docs");
        collection.insertOne(doc , {forceServerObjectId : true},function(err,result){
                if(err) throw err
                console.log(JSON.stringify(result.ops[0]));
        });
        client.close();
});