const toString = Object.prototype.toString; export function is(val: unknown, type: string) { return toString.call(val) === `[object ${type}]`; } export const isDef = (val?: T): val is T => { return typeof val !== 'undefined'; }; export const isUnDef = (val?: T): val is T => { return !isDef(val); }; export const isObject = (val: any): val is Record => { return val !== null && is(val, 'Object'); }; export function isDate(val: unknown): val is Date { return is(val, 'Date'); } export function isNull(val: unknown): val is null { return val === null; } export function isNumber(val: unknown): val is number { return is(val, 'Number'); } export function isPromise(val: unknown): val is Promise { return is(val, 'Promise') && isObject(val) && isFunction(val.then) && isFunction(val.catch); } export function isString(val: unknown): val is string { return is(val, 'String'); } export const isFunction = (val: unknown): val is Function => typeof val === 'function'; export function isBoolean(val: unknown): val is boolean { return is(val, 'Boolean'); } export function isRegExp(val: unknown): val is RegExp { return is(val, 'RegExp'); } export function isArray(val: unknown): val is Array { return val && Array.isArray(val); } export const isClient = () => { return typeof window !== 'undefined'; }; export const isWindow = (val: any): val is Window => { return typeof window !== 'undefined' && is(val, 'Window'); }; export const isElement = (val: unknown): val is Element => { return isObject(val) && !!val.tagName; }; export const isServer = typeof window === 'undefined'; export function isImageDom(o: Element) { return o && ['IMAGE', 'IMG'].includes(o.tagName); }