chainable-simple-validator

A chain-able validator plugin, ideal for using to validate any field, form-data or body of node based api routes.

Getting Started

Installation

// with npm
$ npm install chainable-simple-validator

// with yarn
$ yarn add chainable-simple-validator

Usage

Import

// CommonJS module
const validator = require("chainable-simple-validator");

// ES module
import validator from "chainable-simple-validator";

Application

// Basic type checking
const { value, errors } = validator("First Name").type("string");

// Type checking & when we need exact length
const { value, errors } = validator(01234567890).type("number").exact(11);

// With minimum & maximum boundary
const { value, errors } = validator([1, 2, 3]).type("array").min(3).max(6);

// If it's optional
const { value, errors } = validator(true).nullable().type("boolean");

// If it's an email
const { value, errors } = validator(true).type("string").isEmail();

// Or, pass a custom validator
const { value, errors } = validator(2)
  .type("number")
  .custom((el) => el % 1 === 0, "Must be a whole number");

Full example

const body = {
  name: 'Jhon Smith',
  email: 'john@smith.com',
  password: 'j123456s',
  termsConditions: true,
  profile: 'www.john-smith.com',
  method: 'get'
}

const { value: name, errors: nErrors } = validator(body.name).type('string')
const { value: email, errors: mailErrors } = validator(body.email).isEmail()
const { value: password, errors: passErrors } = validator(body.password).type('string').min(6).max(10).isAlphaNumeric()
const { value: tc, errors: tcErrors } = validator(body.termsConditions).nullable().type('boolean')
const { value: profile, errors: proErrors } = validator(body.profile).nullable().isURL()
const { value: method, errors: mErrors } = validator(body.method).custom(customValidator) // See below example

  if ([nErrors, mailErrors, pErrors, passErrors, tcErrors, proErrors].some((err) => err.length)) {
    console.log(error: {
        firstName: fErrors,
        email: mailErrors,
        password: passErrors,
        termsConditions: tcErrors,
        profile: proErrors,
        method: mErrors,
      })
  }

Custom Method example

const methods = ['get', 'post', 'put', 'delete']
const customValidator (el) => methods.includes(el.toLowerCase()) // This must return boolean
const { errors } = validator('GET').custom(customValidator)

Methods

Methods	Description
validator	The main contructor method which accepts an argument of any valid js data type.
nullable	Only if the value is NOT `null` or `undefind`, validators will be applicable. Apply it if the value is optional. Notice the position above, it's important. Always apply it as second method if needed.
type	It can check any valid JS data type including `Array` & `Object`.
min	Checks if the value has satisfied the minimum length.
max	Checks whether the value has exceeded the maximum length or not.
exact	Checks whether the value has matched the exact length or not.
isEmail	Checks whether it's a valid email or not.
isAlphaNumeric	Checks if the value contains only alpha-numeric characters.
isAlphaNumericWithHyphenUnderscore	Checks if the value contains only alpha-numeric characters, hyphen & underscore.
isURL	Checks whether it's a valid URL or not.
custom	It is also possible to pass your own validator if needed. This method accepts a `handler` as first argument & a string (optional) as second argument which will be returned in `errors` array if the logic not meet. The `handler` must return a boolean. It is also possbile to chain multiple custom methods.

Responses

Response is returned as an object which includes the followings:

Responses	Description
value	The `value` passed to validator method.
errors	Errors are retured as an array. See below example.

Error example

[
  "Type not matched. Expected string, got number",
  "Max length must not exceed 10",
  "Min length must be 6",
  "Length must be 11",
  "This only accepts alpha-numeric value with hyphen & underscore",
  "This is not valid URL",
];

Contributing

Feel free to submit a pull request.

Authors

S.M. Shakil - Initial work - S.M.Shakil

License

This project is licensed under the MIT License - see the LICENSE file for details

smShakil/chainable-simple-validator