credible

credible

Credible is a library for validating objects in node.js or the browser. While it provides several validators out of the box, credible is very unopinionated; mostly, credible simply provides a framework for object validation.

Installation

Credible has one dependency: An A+ promise library, i.e. bluebird or when.js.

Node.js

$ npm install credible --save

Node takes care of the dependency automatically.

Browser

<script src="/bluebird.js"></script>
<script src="/credible.js"></script>

By default, Credible uses bluebird; to use a different implementation, set Credible.Promise to the correct library.

Usage

var rules = {
  name: {
    presence: true
  },
  email: {
    email: true
  }
}

var obj = {
  name: 'Noah Portes Chaikin',
  email: '[e-mail]'
}

var credible = new Credible(rules)
  .run(obj)
  .catch(function (errors) {
    console.log(errors.toJSON());
  })

API

Every method in a Chainable instance returns the instance except credible.run(), which returns a promise.

new Credible(arguments..)

The main Credible constructor optionally accepts the same arguments as credible.rule() (see below).

credible.rule(arguments..)

Used to set new rules. credible.rule() is a variadic function; it accepts any of the following sets of arguments:

credible
  .rule(property, validator, options)
  .rule(property, { validator1: options, validator2: options })
  .rule(validator, options)

validator is either an available validator or a function. To use an available validator, simply pass the validator's name as a string or an object key:

credible
  .rule('name', 'presence', true)
  .rule('name', { length: { greaterThan: 5 } })
  .rule({ email: { email: { if: function (obj) { return obj.email; } } } })

On validation, a validator function is passed the object, the property key (if provided), and options. Validator functions can return promises for asynchronous validation. This is an example validator:

var emailValidator = function (object, property, options) {
  if ( /^[a-z0-9._%+\-]+@[a-z0-9.\-]+\.[a-z]{2,6}$/i.test(object[property])) {
    throw property + ' is an invalid e-mail address';
  }
}

Validators can be sent any number of settings in the options object; the following options are made available to every validator and are handled by the credible object:

Key	Description
if: fn	Only validate if fn returns true. fn is a function; the object being validated is passed to fn as an argument.
unless: fn	Only validate if fn returns false. fn is a function; the object being validated is passed to fn as an argument.
invalid: fn	fn is a function to handle a failed validation; the object being validated is passed to fn as an argument.

credible.if([property], fn)

Only run validator if fn (a function) returns true. fn is passed the object being validated. Optionally, passing property will only execute the test on validators executed on the specified property.

credible
  .if(function (object) {
    return object.foo == 'bar';
  });

credible
  .if('name', function (object) {
    return object.foo == 'bar';
  });

credible.unless([property], fn)

Only run validator if fn (a function) returns false. fn is passed the object being validated. Optionally, passing property will only execute the test on validators executed on the specified property.

credible
  .unless(function (object) {
    return object.foo == 'bar';
  });

credible
  .unless('name', function (object) {
    return object.foo == 'bar';
  });

credible.invalid([property], fn)

Pass fn, a function, for handling a failed validation. fn is passed the object being validated. Optionally, passing property will only execute the function for failed validations executed on the specified property.

credible
  .invalid(function (object) {
    throw 'This object is invalid.';
  });

credible
  .invalid('name', function (object) {
    throw 'This name is invalid.';
  });

credible.run(object)

Run validations on object; returns a promise.

credible
  .run(obj)
  .then(function () {
    console.log('It\'s valid!');
  })
  .catch(function (errors) {
    console.log(errors.toJSON());
  })

Available Validators

length

Property must have a length matching specifications set in options.

Options

Key	Description
greaterThan: number	Property must have a length greater than number
lessThan: number	Property must have a length greater than number
greaterThanOrEqualTo: number	Property must have a length greater than number
lessThanOrEqualTo: number	Property must have a length greater than number
equalTo: number	Property must have a length equal to number

presence

Property must be defined and not empty.

operator

Compare property to a number or another property set in options.

Options

Key	Description
greaterThan: numberOrProperty	Property must have a length greater than numberOrProperty
lessThan: numberOrProperty	Property must have a length greater than numberOrProperty
greaterThanOrEqualTo: numberOrProperty	Property must have a length greater than numberOrProperty
lessThanOrEqualTo: numberOrProperty	Property must have a length greater than numberOrProperty
equalTo: numberOrProperty	Property must have a length equal to numberOrProperty

alpha

Property must contain only letters.

alphaDash

Property must contain only letters and dashes.

alphaNumeric

Property must contain only letters and numbers.

alphaUnderscore

Property must contain only letters and underscores.

email

Property must be a valid e-mail address.

integer

Property must be an integer.

natural

Property must be a positive number.

naturalNonZero

Property must be a positive number greater than zero.

url

Property must be a valid URL.

License & Contributing

• Details on the license can be found here
• Details on running tests and contributing can be found here