findOneAndUpdate method - produces inappropriate results on missing to pass first argument

[jyoti-ui]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.6.3

Node.js version

20.16.0

MongoDB server version

6.8.0

Typescript version (if applicable)

No response

Description

Description:
I encountered unexpected behaviour when using the findOneAndUpdate() method. When I omitted the first argument (the filter object), which typically should contain a unique identifier like _id to identify the document to update, Mongoose did not throw an error as expected.

Current behaviour:
Instead of throwing an error, Mongoose selects and updates the first document in the collection. This behaviour can lead to unintended data modifications, especially in large-scale or data-sensitive applications where precise updates are crucial.

Specifically, it appears that when an empty filter object {} is provided (or implicitly when the filter argument is omitted), Mongoose defaults to updating the first document it finds, potentially based on the natural order of documents in the collection (which often correlates with creation time, but this isn't guaranteed).

Proposed solution:

1. Implement a warning or error when findOneAndUpdate() is called without a filter or with an empty filter object.
2. Alternatively, require an explicit option to allow updates without a specific filter, making the current behavior opt-in rather than default.

This change would help prevent accidental updates to unintended documents and align with the principle of least astonishment, especially for developers new to Mongoose or MongoDB.

Additional context:
This behaviour is particularly concerning in applications where data integrity is paramount. It could lead to silent errors where developers believe they're updating a specific document, but are actually modifying an arbitrary one.

Version information:
[Mongoose -"version": "8.6.3" and MongoDB - "version": "6.8.0", nodejs - version - 20.16.0]

Thank you for considering this issue. I believe addressing it would significantly improve Mongoose's safety and predictability.

Steps to Reproduce

const mongoose = require('mongoose');

// Connect to MongoDB
mongoose.connect('mongodb://localhost:27017/testdb', { useNewUrlParser: true, useUnifiedTopology: true });

// Define a schema
const userSchema = new mongoose.Schema({
  name: String,
  email: String,
  createdAt: { type: Date, default: Date.now }
});

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

// Function to add sample users
async function addSampleUsers() {
  await User.create([
    { name: 'Alice', email: '[email protected]' },
    { name: 'Bob', email: '[email protected]' },
    { name: 'Charlie', email: '[email protected]' }
  ]);
  console.log('Sample users added');
}

// Function to demonstrate the issue
async function demonstrateIssue() {
  console.log('Before update:');
  let users = await User.find();
  console.log(users);

  // This is where the issue occurs:
  // We're calling findOneAndUpdate without a filter
  await User.findOneAndUpdate(
    {}, // Empty filter
    { name: 'Updated User' },
    { new: true }
  );

  console.log('\nAfter update:');
  users = await User.find();
  console.log(users);
}

// Main function to run the demonstration
async function main() {
  await User.deleteMany({}); // Clear the collection
  await addSampleUsers();
  await demonstrateIssue();
  mongoose.connection.close();
}

main().catch(console.error);

To reproduce the error:

1.Make sure you have MongoDB running locally on the default port (27017).
2.Save the above code in a file named reproduce_error.js.
3.Run the script using Node.js:

• node reproduce_error.js
  4.Observe the output. You should see that one of the users (likely the first one added) has been updated without specifying any filter.

Expected Behavior

Expected behaviour:
Mongoose should throw an error or return null when no filter is provided, prompting the developer to supply a unique identifier to target a specific document for update.

[vkarpov15]

Right now this is expected behavior, but we'll consider adding an option to throw an error on empty filters. Right now you can write a plugin to handle this:

mongoose.plugin(schema => {
  schema.pre('findOneAndUpdate', function(next) {
    const filter = this.getFilter();
    if (Object.keys(filter).length === 0) {
      throw new Error('Empty query filters not allowed for findOneAndUpdate');
    }
    next();
  });
});