[Bug] Model.bulkWrite wipes all the document data if no update provided

[AbdelrahmanHafez]

If we for some reason (mostly by mistake) did not provide an update object in updateOne or updateMany operation in Model.bulkWrite, it wipes all the data inside the document except for the _id field.

Here's a test reproducing the issue.

const mongoose = require('./index');
const { Schema } = mongoose;
const assert = require('assert');

const userSchema = new Schema({ name: { type: String, required: true } });

const User = mongoose.model('User', userSchema);

const user = new User({ name: 'Hafez' });

mongoose.connect('mongodb://127.0.0.1:27017/test');
async function run () {
  let threw = false;

  await User.deleteMany();

  await user.save();

  try {
    await User.bulkWrite([{ updateOne: { filter: { _id: user._id } } }]);
  }
  catch (error) {
    threw = true;
  }
  finally {
    assert.equal(threw, true, 'Not providing an update object inside bulk write should throw an error');

    const user = await User.findOne();
    assert.equal(user.name, 'Hafez', 'User data should not be wiped if did not provide an update object.');
  }

}


run().catch(console.error);

What is the expected behavior?

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.

This usually happens when a developer is inserting an update object off by one curly brace, which is fairly easy to miss:

User.bulkWrite([{ updateOne: { filter: { _id: user._id } }, update:{ name: 'Sam' } }])

The expected behavior: for bulkWrite to throw an error instead of just wiping all the data inside the documents .