valley

Functional and lightweight data validation

Install

$ npm install --save valley

Usage

All validation is strict. There is no type conversion and only the specified keys are allowed.

var Validator = require('valley')
var validate = Validator({
  foo: String,
  bar: Number
})
validate({foo: 'a string', bar: 123})
//=> null
validate({foo: 123})
//=> InvalidValueError: 'Invalid data in "foo": expected string, got number'
validate({baz: ''})
//=> InvalidKeyError: 'The following keys are not allowed: baz'

You can also nest validators:

var validateUser = Validator({
  id: Number,
  name: String
})
var validatePost = Validator({
  title: String,
  author: validateUser 
})
validatePost({
  title: 'npm all the things',
  author: {
    id: 1,
    name: 'Ben'
  }
})
//=> null

API

Validator(config) -> function

Creates a validator function that accepts a data object.

config

Required
Type: object

An object where keys correspond to your schema. Values are objects that will be called with value, key, object. When a truthy non-error value is returned, validation passes for that key. When a falsy value is returned, validation fails with a generic error. When an Error is returned, the error message will be used in the validation error.

License

MIT © Ben Drucker