When working with MongoDB, it is common to manipulate and update data objects. However, managing immutability and tracking changes can become challenging. This is where Immer comes to the rescue, providing an easy way to handle immutable updates with minimal effort. In this blog post, we will explore how to integrate Immer into a MongoDB project.

What is Immer?

Immer is a JavaScript library that allows you to work with immutable state in a more intuitive way. It enables you to write code that appears to be mutating an object while maintaining immutability behind the scenes. Immer uses a technique called “structural sharing” to efficiently update immutable data structures.

Integrating Immer with MongoDB

To start using Immer with MongoDB, first, make sure you have Immer installed in your project:

npm install immer

Once installed, you can use Immer in your MongoDB project by following these steps:

Step 1: Import Immer

Import Immer into your JavaScript file where you want to use it:

import produce from 'immer';

Step 2: Use Immer with MongoDB

Now, let’s see how we can use Immer to update a MongoDB document.

Suppose we have a collection named ‘users’ with documents having the following structure:

{
  _id: ObjectId("60e856b9c0e3a84c5942c04f"),
  name: 'John',
  age: 30,
  address: {
    street: '123 Main St',
    city: 'New York',
    country: 'USA'
  }
}

To update the age field of this document using Immer, we can do the following:

const updatedUser = produce(user, (draftUser) => {
  draftUser.age = 31;
});

In the code above, user is the document fetched from the database, and updatedUser is the updated document using Immer. Notice that we modify the age field directly, which gives the illusion of mutating the object. However, Immer handles immutability under the hood.

Step 3: Updating the MongoDB document

Finally, we need to update the document in the MongoDB collection. To achieve this, we can use the MongoDB driver’s updateOne function:

const { MongoClient, ObjectId } = require('mongodb');

const client = new MongoClient('<your_connection_string>');

async function updateMongoDocument(collectionName, filter, updatedDocument) {
  await client.connect();

  const collection = client.db().collection(collectionName);
  await collection.updateOne(filter, { $set: updatedDocument });

  client.close();
}

updateMongoDocument('users', { _id: ObjectId("60e856b9c0e3a84c5942c04f") }, updatedUser)
  .then(() => {
    console.log('Document updated successfully!');
  })
  .catch((err) => {
    console.error('Error updating document:', err);
  });

In the code above, we connect to the MongoDB database, fetch the ‘users’ collection, and update the document by performing an updateOne operation.

Conclusion

Integrating Immer into a MongoDB project gives you the power to manage immutable updates seamlessly. By using Immer’s convenient syntax and MongoDB’s query capabilities, you can easily modify and update documents while maintaining immutability. This leads to cleaner and more maintainable code in your MongoDB projects.

#mongodb #immer