TypeGuards

A lightweight TypeScript library providing runtime type checking utilities with proper TypeScript type narrowing.

Install

npm i @whisklabs/typeguards

Usage

import { isString, isNumber, isArray } from '@whisklabs/typeguards';

// Type narrowing works automatically
function processValue(value: unknown) {
  if (isString(value)) {
    // value is now typed as string
    console.log(value.toUpperCase());
  }
  
  if (isArray(value)) {
    // value is now typed as unknown[]
    console.log(value.length);
  }
}

Functions

• isPresent - not undefined or null
• isUndefined - undefined value
• isDefined - not undefined value
• isObject - object with Generic support
• isString - string value
• isNumber - number value
• isNaN - NaN value
• isDate - Date object
• isArray - Array with Generic support
• isError - any Error types
• isErrorEvent - Error Event
• isFunction - any function
• isRegExp - RegExp value
• isText - non empty string
• isBoolean - boolean value
• isWindow - window object
• isFile - File object
• isFormData - Form Data object
• isBlob - blob value
• isPromiseLike - Promise-like object
• isArrayBuffer - any type of ArrayBuffer
• isTypedArray - any type of TypedArray

Documentation

• Newcomer's Guide - Comprehensive guide for developers new to this project, including architecture details, development patterns, and contributing guidelines