datavader v2.0.0

DATAVADER

A library for object validation

Install

npm i datavader

Usage

import { validate, validateByScheme, addValidatorRule, addParameterRule } from 'datavader';

// it will be tested

const user = {
  name: 'Rick',
  age: 70,
  quality: 'alcoholic',
  catchphrase: 'wubba lubba dub-dub',
  relatives: ['morty', 'summer', 'beth']
};

// use validate method to сheck a single property

validate(user).check('name').with('presence', {exist: true});
validate(user).check('age').with('number', {greaterThan: 60});
validate(user).check('quality').with('exclusion', {values: ['kind', 'gentle']});

// use validateByScheme method to validate the whole object

const scheme = {
  name: {
    presence: {exist: true},
    length: {
      min: 1,
      max: 10,
    },
  },
  age: {
    number: {
      lessThan: 80,
      greaterThanOrEqualTo: 70,
      isEven: true;
      isInteger: true,
    },
  }
  ...
}

validateByScheme(user, scheme);

// use addValidatorRule and addParameterRule to define custom rule

const customValidator = ({firstName, lastName}) => {
  return firstName !== lastName;
}
  
const customOptions = (item) => {
  return {
    firstName: item.firstName,
    lastName: item.lastName,
  }
}

addValidatorRule('firstNameNotEqLastName', customValidator);
addParameterRule('firstNameNotEqLastName', customOptions);

validate(user).check('firstName').with('firstNameNotEqLastName', {});

Validators

presence

validate(object).check(property).with('presence', options)

absence

validate(object).check(property).with('absence', options)

confirmation

validate(object).check(property).with('confirmation', {})

inclusion

validate(object).check(property).with('inclusion', options)

exclusion

validate(object).check(property).with('exclusion', options)

length

validate(object).check(property).with('length', options)

number

validate(object).check(property).with('number', options)

Validation of the entire object

The validators we saw above let you check a single property. But you can check the whole object with the validateByScheme method. This method takes two arguments: 1. object 2. validation scheme

Validation scheme example:

{
  username: {
    presence: {exist: true},
    length: {min: 2, max: 8}
  },
  password: {
    confirmation: {},
    length: {min: 6, max: 20}
  }
}

If there are any errors, it will return an array with failed rules:

{
  username: ['presence'],
  password: ['confirmation', 'length']
}

Customization

You can create your own validator and register one with addValidatorRule method.

For expample let's create isEmail rule.

const isEmailValidator = ({value, domains}) => {
  const reg = new RegExp(`^[a-zA-Z0-9_.+-]+@(?:(?:[a-zA-Z0-9-]+\.)?[a-zA-Z]+\.)?(${domains.join('|')})\.com$`, 'ig');
  return reg.test(value)
}

Now you should register it as a validation rule.

addValidatorRule('isEmail', isEmailValidator, isPrimary);

The last parameter is optional. If it is true the validator will be checked as primary. Primary validators are executed in first order. If a primary validator returns false, all of the following validators will be skipped. By default there are two primary validators - 'presence' and 'absence'.

So, after that you can use it.

validate(user).check('email').with('isEmail', {domains: ['wubba', 'lubba', 'dub']});

By default each validator gets the following parameters:

1. property value
2. and options from with method

You can change it with addParameterRule method.

For example, look at the confirmation validator. It returns true if the object has property with a suffix _confirmation.

const confirmation = (params) => {
  const {value, valueConfirmation} = params;
  return value === valueConfirmation;
}

To set the correct values into parameters we should create special method.

const foo = (item, property, options) => {
  return {
    value: item[property],
    valueConfirmation: item[`${property}_confirmation`],
  }
}

...and register it by validator name.

addParameterRule('confirmation', foo);