Typeh - JavaScript Type Helper Library

A lightweight JS utility for advanced type detection, validation, and enforcement.

Features

• Determine the detailed type of any value (including distinguishing between integers and floats)
• Validate values against expected types with detailed error messages
• Check for common type categories like scalar, numeric, countable, infinite, etc.
• Supports multiple types (e.g. int|float) in validation
• Works in browser and Node.js environments

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Installation

Since TH is a self-contained script, you can include it directly in your project.

npm install typeh --save

Browser

Include the script in your HTML:

<script src="path/to/th.js"></script>

OR

// Node.js
require("typeh");

isA Types

• isCountable()
• isInteger()
• isDouble()
• isNumeric()
• isLong()
• isScalar()
• isInfinite()
• isString()
• isBool()
• isArray()
• isObject()
• isCallable()
• isIterable()
• isNull()
• isFalse()
• isTrue()

Type List

• int
• float
• string
• bool/boolean
• array
• object
• callable
• iterable
• mixed
• null
• false
• true

Others... Like (HTMLElement, regexp, symbol etc.) But support only in define method.

Usage

Variable

// Required
const arr = array([]);
const str = string('Hello World');
const fn = callable(() => {});
const isBool = bool(true);
const num = int(12);
const float = float(12.22);
const values = iterable(new Set([1,2,3,4]));
const obj = object({});
const data = mixed("Foo"); // Allow all types

/* Optional/Required */
function myFun(username, email, number, isAdult) {
  username = string(username); // [required]
  email = _string(email);      // [optional]
  number = _int(number);       // [optional]
  isAdult = bool(isAdult);     // [required]
}

myFun('Foo', null, null, true);

How to use custom Type

const custom = define("string|array|bool", []); // Allow (string, array, boolean) only

// Optional
const optval = define("?string|array"); // Allow (string, array, null, undefined)

Argument typeh

function select(selector, context, results, isSelf) {
  setType({
    string: selector,     // [required]
    HTMLElement: context, // [required]
    array: results,       // [required]
    "?bool": isSelf       // [optional]
  });
}

How To Check Primitive Type

isType(/^[a-z]/);      // Output: regexp
isType(new Date);      // Output: date
isType('Hello');       // Output: string
isType(123);           // Output: number
isType(true);          // Output: boolean
isType(() => {});      // Output: function
isType([]);            // Output: array
isType({});            // Output: object
isType(new Error());   // Output: error
isType(Symbol('Foo')); // Output: symbol

Check To Object Type

toType(12.21);         // Output: float
toType(123);           // Output: int
toType(/^[a-z]/);      // Output: regexp
toType('Hello');       // Output: string

const body = document.body;
toType(body); // Output: HTMLBodyElement