10 Node.js Mongoose Best Practices

Node.js Mongoose is a popular library for interacting with MongoDB databases. It provides a simple and consistent API for interacting with MongoDB databases, making it easier to develop applications that use MongoDB.

However, there are certain best practices that should be followed when using Node.js Mongoose. In this article, we will discuss 10 Node.js Mongoose best practices that will help you write better code and improve the performance of your applications.

1. Avoid using Mongoose for simple CRUD operations

Mongoose is an Object Document Mapper (ODM) that provides a layer of abstraction between the application and MongoDB. It allows developers to define schemas for their data, which can then be used to create models with built-in methods for performing CRUD operations. While this makes it easier to work with complex data structures, it also adds overhead in terms of performance. For simple CRUD operations, such as inserting or retrieving documents from a collection, using native MongoDB commands will generally be faster than using Mongoose.

To avoid using Mongoose for simple CRUD operations, developers should use the native MongoDB driver instead. The MongoDB Node.js driver provides access to all of the same features as Mongoose, but without the added overhead. Additionally, the driver supports Promises and async/await syntax, making it easy to write asynchronous code. Developers can also take advantage of the MongoDB aggregation framework to perform more complex queries on their data. By leveraging the power of the native MongoDB driver, developers can ensure that their applications are running as efficiently as possible.

2. Prefer native Node.js drivers when possible

Native Node.js drivers are written in JavaScript, which is the same language that Mongoose and Node.js use. This means that they can be more tightly integrated with the rest of your codebase, making them easier to debug and maintain. Additionally, native drivers tend to have better performance than third-party drivers since they don’t need to go through an extra layer of abstraction.

Using a native driver also allows you to take advantage of features like connection pooling, which helps improve scalability by reusing existing connections instead of creating new ones for each request. It also makes it easier to implement advanced features such as transactions and sharding.

When using Node.js Mongoose, you should always check if there’s a native driver available before opting for a third-party one. If there is, then you should prefer it over other options due to its improved performance, tighter integration, and additional features.

3. Leverage the power of MongoDB aggregation framework

MongoDB aggregation framework is a powerful tool for data processing and analysis. It allows users to perform complex operations on their data, such as filtering, sorting, grouping, and transforming documents into aggregated results. This makes it an ideal choice when working with Node.js Mongoose, since the library provides easy access to the underlying database.

Using MongoDB aggregation framework in combination with Node.js Mongoose can help developers create efficient queries that are optimized for performance. By leveraging the power of both technologies, developers can quickly and easily retrieve large amounts of data from the database without having to write complex SQL statements or manually iterate through each document. Additionally, the aggregation framework can be used to aggregate data across multiple collections, allowing developers to build more sophisticated applications.

Furthermore, MongoDB aggregation framework also supports various operators which allow developers to manipulate data in different ways. These operators include $match, $project, $group, $sort, $skip, and $limit, among others. With these operators, developers can filter, sort, group, and transform documents into aggregated results, making it easier to work with large datasets.

4. Create indexes to improve query performance

Indexes are special data structures that store a small portion of the collection’s data set in an easy-to-traverse form. When Mongoose queries a collection, it can use the index to quickly determine which documents match a query without having to scan every document in the collection. This makes queries much faster and more efficient.

Creating indexes is relatively simple with Node.js Mongoose. All you need to do is define the fields you want to index on your schema, then call the ensureIndex() method on the model. The ensureIndex() method takes two arguments: the field or fields to be indexed, and an optional options object. You can also specify additional parameters such as unique, sparse, and expireAfterSeconds. Once the index has been created, Mongoose will automatically use it when querying the collection.

5. Validate your data before saving it in the database

Validating data is important because it ensures that the data stored in your database is accurate and consistent. This helps to prevent errors, maintain data integrity, and ensure that all of the data is valid for use.

Mongoose provides a number of built-in validation methods which can be used to validate data before saving it in the database. These include type checking, required fields, min/max values, regular expressions, custom validators, and more. You can also create custom validations using Mongoose middleware. Additionally, you can use third-party libraries such as Joi or express-validator to perform additional validation checks.

6. Leverage virtuals and middleware functions for complex business logic

Virtuals are a Mongoose feature that allow you to define custom getters and setters for document properties. This is useful when dealing with complex business logic, as it allows you to create custom functions that can be used to manipulate data before it is stored in the database or returned to the client. For example, if you need to encrypt sensitive user information before storing it in the database, you could use virtuals to do so.

Middleware functions are another powerful tool provided by Mongoose. They provide a way to hook into various stages of the document lifecycle (e.g., pre-save, post-save, etc.) and execute custom code at those points. This is especially useful for implementing complex business logic, such as validating data before saving it to the database or sending an email notification after a document has been saved.

7. Make use of mongoose population for related documents

Mongoose population allows you to easily retrieve related documents from different collections in a single query. This is especially useful when dealing with complex data models that require multiple joins, as it eliminates the need for writing custom code and makes your queries more efficient.

To use mongoose population, you first define a schema for each collection in your database. Then, you can specify which fields should be populated by adding a “ref” property to the field definition. The value of this property should be the name of the model associated with the referenced document.

Once the schemas are defined, you can then use the populate() method on a Mongoose query object to automatically fetch the related documents. You can also specify additional criteria such as sorting or limiting the number of results returned.

8. Utilize lean() method to get plain JavaScript objects from Mongoose queries

The lean() method is a Mongoose query helper which returns plain JavaScript objects instead of Mongoose documents. This means that the returned object will not have any of the Mongoose-specific getters, setters, or other features associated with Mongoose documents.

Using the lean() method can be beneficial in several ways. It allows for faster execution times since it does not need to convert the results into Mongoose documents. Additionally, it reduces memory usage by avoiding the creation of extra Mongoose documents. Furthermore, it simplifies debugging and testing since the returned objects are plain JavaScript objects.

To use the lean() method, simply add .lean() to the end of your Mongoose query. For example:

const user = await User.findOne({ name: ‘John’ }).lean();

9. Don’t forget to close the connection after each request

When a connection is left open, it can cause memory leaks and other performance issues. This is because the server will keep allocating resources to that connection until it is closed. Additionally, leaving connections open can lead to an increase in latency as more requests are made.

To ensure that connections are properly closed after each request, Mongoose provides a connection.close() method which should be called at the end of every request. This ensures that any resources allocated to the connection are released back to the server, preventing memory leaks and improving overall performance.

10. Enable debug mode only during development

Debug mode is a feature of Mongoose that allows developers to see detailed information about the queries and operations being performed on their database. This can be extremely helpful for debugging issues, but it also has some drawbacks. For example, enabling debug mode will slow down your application’s performance since it requires additional processing power to generate the extra output. Additionally, if debug mode is enabled in production, sensitive data such as passwords or API keys may be exposed.

To ensure that debug mode is only used during development, it should be set up using environment variables. Environment variables are key-value pairs that allow you to store configuration settings outside of your codebase. By setting an environment variable called “DEBUG” with a value of “true”, you can enable debug mode when running your application locally. When deploying to production, simply set the DEBUG environment variable to false, which will disable debug mode.