Model.remove()&deleteMany() solution not working

JavaScript
#1

The error I was receiving was :

(node:998) [MONGODB DRIVER] Warning: collection.remove is deprecated. Use deleteOne, deleteMany, or bulkWrite instead.
SyntaxError: Unexpected token o in JSON at position 1
    at JSON.parse (<anonymous>)
    at /home/runner/boilerplate-mongomongoose/server.js:346:29
    at /home/runner/boilerplate-mongomongoose/node_modules/mongoose/lib/model.js:4919:18
    at processTicksAndRejections (internal/process/task_queues.js:79:11)

So I assumed that remove() and deleteMany() were returning an object instead of a string. So I changed my code to :

const removeManyPeople = (done) => {
  const nameToRemove = "Mary";
  Person.deleteMany({name: nameToRemove}, (err, response) => {
    if(err) return console.error(err);
    console.log(JSON.stringify(response))
    done(null, JSON.stringify(response));
  })
};

which returned successful delete POST without error. However, the test still FAILS and I cannot pass the test. How can I fix this?:

Your app is listening on port 3000
OPTIONS
POST
(node:1069) [MONGODB DRIVER] Warning: collection.remove is deprecated. Use deleteOne, deleteMany, or bulkWrite instead.
{"deletedCount":2}

Your project link(s)

solution: https://replit.com/@catherineyang2/boilerplate-mongomongoose

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Safari/537.36

Challenge: Delete Many Documents with model.remove()

Link to the challenge:

2 Likes
'Remove' mongoose method throws Unexpected token o
#2

First check this SO answer about this error
https://stackoverflow.com/questions/38380462/syntaxerror-unexpected-token-o-in-json-at-position-1?rq=1

If you check the code at server.js line 346 it’s in an if statement

if (data.ok === undefined) {

The code expects an ok property and if it’s not present, it tries to parse the data as json.
The problem here is that data is already an object, it’s not a string. So string form of the data is [object Object] and the first o is causing the Unexpected token o in JSON at position 1 error.

As as workaround you can try this:

const removeManyPeople = (done) => {
  const nameToRemove = "Mary";
  Person.remove({name:nameToRemove},(err,data)=>{
    if(err) return console.error(err);
    data.ok = true;
    data.n = data.deletedCount;
    done(null , data);
  });
};

data.ok is for the aforementioned if statement and data.n is for server.js line 353.

12 Likes
#3

I would suggest checking your versions for Mongoose and MongoDB. I recently had this issue and it’s being updated to show the correct versions in the curriculum.

6 Likes
#4

I had the same problem, it works for me ,
thanks for your help. :wink:

1 Like
#5

I had a similar issue.
Your suggesteed solution worked for me.
Thank you.

1 Like
#6

Another solution will be just to use Model.deleteMany() instead of Model.remove(). That one worked for me.

#7

worked for me
but do you know what is the cause for this ?
is it the mongoose version ?

#8

I have passed a lot of hours researching on the internet for the resolution of this challenge. I was almost ready to shoot myself (just kidding :sweat_smile:, I do not have a gun) when I realized it worked!

Thank you, snowy.tmp, for your data.ok = true; , it was one piece of the puzzle, but an important one!

Ironically, until this 11th challenge, I was using an updated version of both mongoDB and mongoose, without any kind of warnings or errors.

I think I was able to retrace all the steps I took, so, I hope this message can be helpful to somebody.

(My case is a mongoDB, mongoose, and Replit project.
I can not say it will work for others who choose a different “path”.)

:warning: All these steps are important because almost all of them surpass warnings and errors that may occur from the fact of installing older version packages to be able to pass the tests. :warning:

1. At Package.json:

  • Inside the dependencies, really write these specific packages (manually) as they are (without any tilde or caret) to lock their version:
"mongodb": "3.6.0",
"mongoose": "5.4.0"

2. At the Console/Bash:

  • Execute: $ npm install

3. At Replit’s SECRETS (environment variables):

  • Add a name (e.g. “myFirstDatabase”) to the MongoDB URI connect link string (between / and ?retry):

mongodb+srv://USERNAME:PASSWORD@cluster0.xyykl.mongodb.net/myFirstDatabase?retryWrites=true&w=majority

  • Change the words “USERNAME” and “PASSWORD” according to your case.

4. At myApp.js:

4.1. At the mongoose connection, apply the following changes to the options object:

mongoose.connect(MONGO_URI, { useNewUrlParser: true })

4.2. Both methods work (just choose one): Model.remove() and Model.deleteMany().

4.3. Write the code:

const removeManyPeople = (done) => {
  const nameToRemove = "Mary";
  Person.remove({name: nameToRemove}, (err, data) => {
    if(err) return console.log(err);
    data.ok = true;
    console.log(data);
    done(null, data);
  });
};

5. RUN replit.

6. Toward the “finish line”:

  • After clicking “I’ve completed this challenge” on FCC 11th Challenge Page, it should take around 5 or 6 seconds until success message pops up.
  • The console shall log:
    • the word “OPTIONS” followed by “POST”, and
    • the “data” object.
  • At this time, the operation has succeeded.

NOTE 01: At MongoDB own database, you will not find any document created whatsoever, as the FCC test creates and deletes those.

NOTE 02: I only had this warning appearing in the console:

“DeprecationWarning: collection.count is deprecated, and will be removed in a future version. Use collection.countDocuments or collection.estimatedDocumentCount instead”

#9