io-validate

Runtime data validator.

Note

• This package used to be named param-check.

Install

npm install io-validate --save

Usage

Basic usage

import v from 'io-validate';

function fn(arg1, arg2) {
  v(arg1).isString();

  // If you want to print variable name, pass name as the 2nd parameter.
  v(arg2, 'arg2').greaterThan(1).lessThan(2);
}

not operator

import v from 'io-validate';

function fn(arg) {
  v(arg).not.isString();
}

Chain call

All validators of io-validate support chain calls. A chain call means an "and" expression.

import v from 'io-validate';

function fn(arg) {
  v(arg).gt(1).lt(2); // arg > 1 && arg < 2
}

Specific validator

If you want smaller dependence size, just import specific validators.

import v from 'io-validate/minimum';
import isString from 'io-validate/lib/validators/isString';

v.register(isString);

function fn(arg) {
  v(arg).isString();
}

Custom validator

import v from 'io-validate';
import isNumber from 'lodash/isNumber';

function isEven(target, name) {
  return isNumber(target) && !(target % 2);
}

check.register('isEven', isEven);

function fn(arg) {
  v(arg).isEven();
}

Custom chain

import v from 'io-validate'

function isEven (target, name) {
  return !(target % 2)
}

function isOdd (target, name) {
  return target % 2
}

function next (target) {
  return return target + 1
}

v.register('isEven', isEven, next)
v.register('isOdd', isOdd, next)

function fn (arg) {
	v(arg).isEven().isOdd()
}

Plan

plan is used to generate combinable validators.

By contrast, v('').isString() executes the validator isString immediatly, v.plan.isString() doesn't execute any validator, just return a combinable isString validator.

import v from 'io-validate';

v('').isString();

v('').or(v.plan.isString, v.plan.isNumber);

Validators

same

Validate that the input value is the same to ('===') the reference value.

v(1).same(1);

v({ a: 1 }).same({ a: 1 }); // Bang!

among

Validate that the input value is among the reference options.

v(1).among(1, 2, 3, 4);

equal | eq

Validate that the input value is equal to the reference value.

You may pass in a custom equal function instead of the default equal algorithm which is a simplified implemention of deep-equal.

v(1).equal(1);
v(1).eq(1);

v('foobar').equal('Foobar', (left, right) => left.toLowerCase() === right.toLowerCase());

equalOrGreaterThan | egt

Validate that the input number is equal to or greater than the reference number.

v(1).equalOrGreaterThan(0);
v(1).egt(1);

equalOrLessThan | elt

Validate that the input number is equal to or less than the reference number.

v(1).equalOrLessThan(2);
v(1).elt(1);

greaterThan | gt

Validate that the input number is greater than the reference number.

v(1).greaterThan(0);
v(1).gt(0);

lessThan | lt

Validate that the input number is less than the reference number.

v(1).lessThan(2);
v(1).lt(2);

within

Validate that the input number is whthin the reference range(s).

Syntax:

• Open range is denoted in parentheses.
• Closed range is denoted by square brackets.

v(1).within('(0, 2)', '[-1, 3.5]');

v(0).within('[0, 1)', '(-1, 0]');

is | isXXX

Runtime type checking based on lodash.

v(1).is('number', 'string') // number or string

v(1).isNumber()

lodash type validators

var isArguments = require('lodash/isArguments');
var isArray = require('lodash/isArray');
var isArrayBuffer = require('lodash/isArrayBuffer');
var isArrayLike = require('lodash/isArrayLike');
var isArrayLikeObject = require('lodash/isArrayLikeObject');
var isBoolean = require('lodash/isBoolean');
var isBuffer = require('lodash/isBuffer');
var isDate = require('lodash/isDate');
var isElement = require('lodash/isElement');
var isEmpty = require('lodash/isEmpty');
var isError = require('lodash/isError');
var isFunction = require('lodash/isFunction');
var isLength = require('lodash/isLength');
var isMap = require('lodash/isMap');
var isNative = require('lodash/isNative');
var isNil = require('lodash/isNil');
var isNull = require('lodash/isNull');
var isNumber = require('lodash/isNumber');
var isObject = require('lodash/isObject');
var isObjectLike = require('lodash/isObjectLike');
var isPlainObject = require('lodash/isPlainObject');
var isRegExp = require('lodash/isRegExp');
var isSet = require('lodash/isSet');
var isString = require('lodash/isString');
var isSymbol = require('lodash/isSymbol');
var isTypedArray = require('lodash/isTypedArray');
var isUndefined = require('lodash/isUndefined');
var isWeakMap = require('lodash/isWeakMap');
var isWeakSet = require('lodash/isWeakSet');

Other type validators

var isExist = function isExist(o) {
  return !(isUndefined(o) || isNull(o));
};

instanceOf

Validate that the input value is an instance of the reference class.

We use the keyword 'instanceof' to implement this validator.

class Foobar {}
const fb = new Foobar();

v(fb).instanceOf(fb);

isArrayOf

Validate that the input value is an array of valid values.

v(fb).isArrayOf(fb, (el) => el % 2);

match

Regular expression validator.

v('foobar42').match(/\w+\d+/);

patterns

Common regular expression validators.

Available validators:

• matchEmail
• matchURL
• matchIP

v('[e-mail]').matchEmail();

has | hasOwn

Validate that the input value has an OWN property of the reference name.

has() returns a validatable object that encapsulates the validated property if it exists.

If you want the validatable object that encapsulates the origin input value, use "owner" or "_" operator.

const obj = {
  a: {
    b: {
      c: 'foobar',
    },
  },
};

v(obj).has('a').has('b').has('c');
v(obj).has('a').owner.has('a').owner.has('c');
v(obj).has('a')._.has('a')._.has('a');

got

Validate that the input value has a property (maybe NOT own property) of the reference name.

const obj = {
  a: {
    b: {
      c: 'foobar',
    },
  },
};

v(obj).got('a').got('b').got('c');
v(obj).got('a').got('__proto__').got('constructor');

length

Equivalent of validator got('length').

const arr = [1, 2, 3];

v(arr).length().eq(3);

and

Validator of "and" expression.

It is often better to express "and" relationships using chain calls, but this API combines functions and plans.

v('Foobar').and(v.plan.isString, (target) => {
  return target.toLowerCase() === 'foobar';
});

or

Validator of "or" expression.

v(1).or(
  v.plan.isString,
  v.plan.and(v.plan.isNumber(), (target) => target % 2)
);

meet

Single parameter version of validator and().

v('Foobar').meet(v.plan.isString);