The Problem
Validation in JavaScript can be a headache. Libraries like Joi often feel like overkill for simple use cases, bogging you down with configuration and dependencies. You just want something that’s fast and easy to use, without the bloat.
What This Does
Enter fastest-validator, a lightweight library that promises speed and simplicity. Found in the lib/ directory, the core validator logic is encapsulated in validator.js, which allows you to define schemas and validate data effortlessly. The examples/ folder provides handy snippets for common use cases, including how to integrate it in a React app with examples/with-react-nextjs/.
The library supports over 20 built-in validators, and if those don’t fit your needs, you can create custom validators. Want to halt validation on the first error? Just pass haltOnFirstError: true when creating your Validator instance. The whole setup is straightforward, and with npm install fastest-validator, you're off to the races.
Real-World Use
Imagine you’re building a REST API and need to validate incoming requests. Instead of writing verbose validation logic, you can define a schema like this:
Simply call check(data) to validate your object. If there’s an issue, you’ll get a clear error response without the noise.
The Bottom Line
fastest-validator is a solid choice if you need quick, no-frills validation without the overhead of larger libraries. It’s perfect for small to medium projects where performance matters. Just keep in mind, if your validation needs are complex, you might outgrow it. But for most cases, it’s a breath of fresh air.