vtypes-invariant

invariant-style validation for validate.js

• About
• Installation
• Usage
• Available Options
• Create sub-validators
• License

About

The invariant validator allows you to define a condition/function that has to evaluate to a strict true value for it to be valid.

The concept is similar to the invariant library, but for validate.js.

Note: This validator will always be invoked by default. Thus it will check even when value is undefined or null. You can disable this behaviour by passing presence: false;

Installation

Using npm:

$ npm i --save vtypes-invariant

const validate = require('validate.js');
const invariant = require('vtypes-invariant');

// you can then proceed to register the required validators.
validate.validators.invariant = invariant;

Usage

const constraints = {
  attr: {
    condition: (value) => value === 'bar'
  }
}

validate({}, constraints);
// => {attr: ["Attr invariant violation"]}

validate({attr: 'bar'}, constraints);
// => undefined

validate({attr: 'foo'}, constraints);
// => {attr: ["Attr invariant violation"]}

const constrants = {
  attr: {
    presence: false,
    condition: (value) => value === 'bar'
  }
}

validate({}, constraints);
// => undefined

For more examples, check out the test files in this package's source folder.

Available Options

| name | type | default | description | | --------- | -------- | --------------------- | -------------------------------------------------------------------------------- | | condition | function | undefined | Returns a truthy value for validation to pass | | message | string | invariant violation | Error message | | presence | boolean | true | By default, runs even though value is undefined or null | | truthy | boolean | false | Allow the conditional function to return truthy values instead of strict boolean |

The condition function takes in (value, key, attributes) of the validator.

Create sub-validators

The invariant validator also provides a invariant.create function which lets you quickly create new validators by calling invriant.create(condition, message), providing a condition and message.

License

vtypes-invariant is MIT licensed