validation-helper-lib

Full-stack input validation and sanitization: validators, schema-based run, and type coercion. Use in forms (client) and API handlers (server) for consistent rules.

Features

• Zero dependencies
• Validators — required, isString, isEmail, isUrl, minLength, maxLength, min, max, oneOf, pattern, custom
• Schema — run(schema, data) → { valid, errors }, compose, field()
• Sanitize — trim, toNumber, toInteger, toBoolean, trimObject, pickAndTrim

Installation

npm install validation-helper-lib

Quick Start

const {
  required,
  isEmail,
  minLength,
  run,
  runFlat,
  compose,
  trim,
  toNumber,
} = require('validation-helper-lib');

// Single validator
required('');        // 'This field is required'
isEmail('[email protected]');   // null (valid)
minLength('hi', 3);   // 'Must be at least 3 characters'

// Schema (e.g. API body or form state)
const schema = {
  email: [required, isEmail],
  password: [required, (v) => minLength(v, 8)],
  age: [required, (v) => (v >= 0 && v <= 150 ? null : 'Invalid age')],
};
const { valid, errors } = run(schema, { email: 'bad', password: 'short' });
// valid === false, errors === { email: ['Invalid email'], password: ['Must be at least 8 characters'] }

// With api-helper-lib
// const validation = runFlat(schema, body);
// if (!validation.valid) return validationErrorResponse(validation.errors);

// Sanitize
trim('  hello  ');   // 'hello'
toNumber('42');      // 42
toBoolean('true');   // true

Subpath Imports

const validators = require('validation-helper-lib/validators');
const schema = require('validation-helper-lib/schema');
const sanitize = require('validation-helper-lib/sanitize');

API

validators — required, isString, isNumber, isInteger, isBoolean, isEmail, isUrl, minLength, maxLength, min, max, inRange, oneOf, pattern, custom

schema — run, runFlat, compose, field

sanitize — trim, toNumber, toInteger, toBoolean, toString, trimObject, pickAndTrim

License

MIT