Mongoose updating object field properties in document

Question

I am having a problem where an object in my document would not get updated. In my Class Model, there's a field called sentiment of type Object as the following:

sentiment: {
  terrible: 0,
  bad: 0,
  okay: 0,
  good: 0,
  fantastic: 0
}

The way I implemented sentiment in my model is as following:

sentiment: Object

To update the property, I am passing an object with the field sentiment that contains the actual sentiment:

{ sentiment: 'good' } // this is what req.body contains

I am doing this:

const classFound = await Class.findById(req.params.classId);
if (classFound) {
  classFound.sentiment[req.body.sentiment] += 1;
  await classFound.save();
}

But when I retrieve the class, the sentiment object remains unchanged. I am not sure where the bug is because when I log out classFound after save() , I get the updated sentiment object.

EDIT

Class.js // class Schema
const classSchema = new Schema({
  name: {
    type: String,
    required: true
  },
  abbr: {
    type: String,
    required: true
  },
  sentiment: {
    terrible: { type: Number, default: 0 },
    bad: { type: Number, default: 0 },
    okay: { type: Number, default: 0 },
    good: { type: Number, default: 0 },
    fantastic: { type: Number, default: 0 }
  }
});

Answer 1

try this

const update = (query, body) => {
    return new Promise((resove, reject) => {
        Class.update(query, body, (err, data) => {
            if (err)
                return reject(err);
            return resove(data);
        });
    });
}

const classFound = await Class.findOne({
    _id: req.params.classId
}).exec(); // exec returns promise
if (classFound) {
    const sentiment = req.body.sentiment;
    classFound.sentiment[sentiment] = classFound.sentiment[sentiment] ? classFound.sentiment[sentiment] + 1 : 1;
    const query = {
        _id: req.params.classId
    };
    const body = {
        $set: {
            sentiment: classFound.sentiment
        }
    };
    await update(query, body);
}