PsychoType

Simple and lightweight type validation library for node.

const type = require('psycho-type')
const referece = {
  'foo': type.string(),
  'bar': type.number()
}

type.check( reference, {
  'foo': 'string',
  'bar': 3
})
// => true

Installation

This is a node.js module available via npm. Requires node.js 4.9.1 or highter.

$ npm i psycho-type

Usage

This module can be used for runtime type validation for one item or (nested) object.

/* Validating single item */
const valid_type = type.string()

/* You can do it with check function */
type.check( valid_type, 'string' )
//=> true

/* Or only with valid type function */
valid_type( 'string' )
//=> true

Object validation is a little similar to TypeScript Interfaces.

/* Validating objects */
const reference = {          // Reference object, contain types.
  'foo': type.string(),      //
  'bar': type.boolean(),     //
  'fizz': {                  //
    'buzz': type.number()    //
  }
}

const object = {             // Object to validate.
  'foo': 'String',           //
  'bar': true,               //
  'fizz': {                  //
    'buzz': 15               //
  }
}

type.check( reference, object )
//=> true

Types / Methods

• Basic types
  • Any
  • String
  • Numbers
    • Any Number
    • Number
    • BigInt
  • Boolean
  • Function
  • Object
  • Array
  • Symbol
  • Undefined
  • Null
  • NaN
• Complex types
  • No Value
  • Empty
  • Array Of <types>
  • Enum <values>
  • Some Of <types>
  • Not <types>
• Check Method
• Of Method

Basic Types

Any

Just returns true on everything.

    Param {Any} item
    Return {Boolean}

const any = type.any()

any( * )
//=> true

String

Allow both ' "string" ' and ' new String() '.

    Param {Any} item
    Return {Boolean}

const string = type.string()

string( 's' )
//=> true

string( 3 )
//=> false

string( new String() )
//=> true

Numbers

Any Number

Allow number, bigInt or NaN.

    Param {Any} item
    Return {Boolean}

const anyNumber = type.anyNumber()

anyNumber( 3 )
//=> true

anyNumber( BigInt() )
//=> true

anyNumber( '3' )
//=> false

Number

Allow only regular number.

    Param {Any} item
    Return {Boolean}

const number = type.number()

number( 3 )
//=> true

number( BigInt() )
//=> false

number( '3' )
//=> false

BigInt

Allow only BigInt. Have two aliases:

• bigInt
• bigNumber

    Param {Any} item
    Return {Boolean}

const bigint = type.bigInt()

bigint( 3 )
//=> false

bigint( BigInt() )
//=> true

bigint( '3n' )
//=> false

Boolean

Allow only boolean. Have two aliases:

• bool
• boolean

    Param {Any} item
    Return {Boolean}

const bool = type.bool()

bool( 3 )
//=> false

bool( true )
//=> true

bool( new Boolean(1) )
//=> true

Function

Allow only functions.

! Any class/constructor will return true !

    Param {Any} item
    Return {Boolean}

const func = type.function()

func( 3 )
//=> false

func( () => {} )
//=> true

func( Boolean ) // Because ' Boolean ' it's the constructor
//=> true

Object

Allow only objects.

! Doesn't allow null or basic data types even if it's created by ' new Object() ' !

    Param {Any} item
    Return {Boolean}

const object = type.object()

object( new Object() )
//=> true

object( new Object(3) )
//=> false

object( {} )
//=> true

Array

Allow array with any value.

    Param {Any} item
    Return {Boolean}

const array = type.array()

array( [] )
//=> true

array( new array( 3, 4 ) )
//=> true

array( {} )
//=> false

Symbol

Allow symbol.

    Param {Any} item
    Return {Boolean}

const symbol = type.symbol()

symbol( [] )
//=> false

symbol( Symbol( '3' ) )
//=> true

symbol( {} )
//=> false

Undefined

Allow only undefined.

    Param {Any} item
    Return {Boolean}

const not_defined = type.undefined()

not_defined( [] )
//=> false

not_defined( null )
//=> false

not_defined( undefined )
//=> true

Null

Allow only null.

    Param {Any} item
    Return {Boolean}

const null_type = type.null()

null_type( [] )
//=> false

null_type( null )
//=> true

null_type( undefined )
//=> false

NaN

Allow only NaN. Have two aliases:

• nan
• NaN

    Param {Any} item
    Return {Boolean}

const null_type = type.null()

null_type( [] )
//=> false

null_type( null )
//=> true

null_type( undefined )
//=> false

Complex Types

No Value

Allow ' no value ' types such as undefined, null, NaN.

    Param {Any} item
    Return {Boolean}

const no_value = type.noValue()

no_value( [] )
//=> false

no_value( null )
//=> true

no_value( undefined )
//=> true

Empty

Allow ' empty ' values such as {}, [], '' and 0.

! Doesn't work NOW with values created from constructor ( like ' new String() ' ) !

    Param {Any} item
    Return {Boolean}

const empty = type.empty()

empty( [] )
//=> true

empty( null )
//=> false

empty( new String() )
//=> false

Array Of <types>

Allow array with some types.

    Param {Array} ...types
    Return {function}:
        Param {Array} item
        Return {Boolean}

const array = type.arrayOf(
                type.string(),
                type.boolean()
              )

array([ 'string', true ])
//=> true

array( null )
//=> false

array( new Boolean() )
//=> true

Enum <values>

Allow only some values.

! Doesn't work NOW for values, created by like ' new Number() ' !

    Param {Array} ...values
    Return {function}:
        Param {Any} item
        Return {Boolean}

const enum = type.enum(
               'value',
               3
             )

enum( 'value' )
//=> true

enum( 3 )
//=> true

enum( 4 )
//=> false

Some Of <types>

Allow some types.

    Param {Array} ...types
    Return {function}:
        Param {Any} item
        Return {Boolean}

const some = type.someOf(
               type.string(),
               type.boolean()
             )

some( 'value' )
//=> true

some( 3 )
//=> false

some( false )
//=> true

Not <types>

Inverted ' someOf '. Disallow some types.

    Param {Array} ...types
    Return {function}:
        Param {Any} item
        Return {Boolean}

const not = type.not(
              type.string(),
              type.boolean()
            )

some( 'value' )
//=> false

some( 3 )
//=> true

some( false )
//=> false

'Check' Method

Compare types of input object with reference.

! Method will return false if reference is not valid, without any exeption !

    Param {Object|Function} reference/type
    Return {Boolean}

const reference = {          // Reference object, contain types.
  'foo': type.string(),      //
  'bar': type.boolean(),     //
  'fizz': {                  //
    'buzz': type.number()    //
  }
}

const object = {             // Valid object.
  'foo': 'String',           //
  'bar': true,               //
  'fizz': {                  //
    'buzz': 15               //
  }
}

type.check( reference, object )
//=> true

'Of' Method

Returns type of input even if input created like ' new Object(3) ' and has custom types: 'null', 'NaN'.

    Param {Any} item
    Return {String}

type.of( Number );
//=> 'function'

type.of( null );
//=> 'null'

type.of( NaN );
//=> 'NaN'

type.of( new Object('string') );
//=> 'string'

Contacts

If you have any questions or suggestions please contact me: dmitry.kokhanevich@gmail.com