@the-neon/validation

Method argument validation for Neon using decorators.

Install

npm install @the-neon/validation

Requires @the-neon/core as a peer dependency.

Usage

import { Validate, Validator } from "@the-neon/validation";

Validators

Built-in Validators

• Validator.email — Validates email format
• Validator.notEmpty — Validates not null/undefined/empty string
• Validator.uuid — Validates UUID format
• Validator.greaterThanZero — Validates number > 0

Example

class UserService {
  @Validate({
    email: Validator.email,
    name: Validator.notEmpty,
  })
  async createUser(email: string, name: string) {
    // validation runs before the method
  }
}

// Throws InputError if validation fails
await userService.createUser("invalid-email", "");

Custom Validation Functions

import { Validate, Validator } from "@the-neon/validation";

const customValidator = (value: any) => {
  if (!isValid(value)) {
    throw new Error("Custom validation failed");
  }
};

class MyService {
  @Validate({
    data: customValidator,
  })
  async process(data: any) {
    // ...
  }
}

API

@Validate

Decorator that validates method arguments:

@Validate(validators: {
  [paramName: string]: Validator | Validator[] | ValidationFunction | ValidationFunction[];
}, functions?: ValidationFunction | ValidationFunction[])

Validator

Enum of built-in validators:

Validator.email
Validator.notEmpty
Validator.uuid
Validator.greaterThanZero