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mr.z_fullstack

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I Got Tired of Repeating Validation Logic in Every Node.js Project — So I Built Zero Validation

#typescript #opensource #webdev #node

How I Published My Own Validation Package on npm

As developers, we've all done this:

if (!email) {
  throw new Error("Email is required");
}

if (typeof email !== "string") {
  throw new Error("Email must be a string");
}

if (!email.includes("@")) {
  throw new Error("Invalid email");
}
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Now imagine doing this for:

  • User Registration
  • Login APIs
  • Product Creation
  • Payment Requests
  • Admin Panels
  • Microservices

The validation code starts growing faster than the actual business logic.

The Problem

In many Node.js projects, validation ends up being:

  • Repetitive
  • Hard to maintain
  • Inconsistent across APIs
  • Difficult to scale

Every endpoint contains similar checks:

if (!name) ...
if (!email) ...
if (!password) ...
if (password.length < 8) ...
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As projects grow, these validations become scattered throughout the codebase.

Existing Solutions

There are already some excellent validation libraries available:

  • Zod
  • Joi
  • Yup
  • Express Validator

I've used many of them and they're great.

But for some smaller projects and APIs, I wanted something:

  • Lightweight
  • Easy to understand
  • Minimal setup
  • Zero configuration
  • TypeScript friendly

That's what led me to build Zero Validation.

Introducing Zero Validation

Zero Validation is a lightweight schema validation package for Node.js and TypeScript applications.

The goal is simple:

Define your validation schema once and validate data consistently everywhere.

Installation 

npm install zero-validation
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Basic Example 

import { z } from "zero-validation";

const userSchema = z.object({
  name: z.string(),
  email: z.email(),
  age: z.number(),
});

const result = userSchema.parse({
  name: "John",
  email: "john@example.com",
  age: 25,
});

console.log(result);
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Handling Validation Errors 

const result = userSchema.safeParse(data);

if (!result.success) {
  console.log(result.errors);
}
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Instead of crashing your application, you can safely inspect validation errors and return meaningful API responses.

Why I Built It

This project started as a learning exercise.

I wanted to understand:

  • How schema validation libraries work internally
  • TypeScript type inference
  • Package publishing
  • Open-source maintenance

What started as a simple experiment eventually became a reusable package that can be installed directly from npm.

What I Learned While Building It

Building an npm package taught me much more than validation itself.

Some lessons:

1. API Design Matters

Developers prefer:

schema.parse(data);
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over

validateDataAgainstSchemaUsingCustomFunction(data);
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Small API decisions have a huge impact on usability.

2. Documentation Is Part of the Product

A package without documentation is almost impossible to adopt.

Writing examples, README files, and usage guides often takes longer than writing the code itself.

3. Error Messages Matter

Developers spend most of their time fixing errors.

Good validation libraries provide clear and actionable feedback.

Future Improvements

Some features I'm planning to add:

  • Custom validators
  • Nested schemas
  • Array validation
  • Async validation
  • Better TypeScript inference
  • Express middleware integration

Open Source Feedback Welcome

This project is still evolving, and I'd love feedback from the developer community.

Questions I'd love to hear:

  • What validation features do you use most?
  • What do you dislike about existing validation libraries?
  • What would make a lightweight validation library more useful?

If you'd like to check out the project, feel free to try it and share your thoughts.

💡 Quick Links

📦 npm Package:
https://www.npmjs.com/package/zero-validation

Happy coding :)

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