const toString = Object.prototype.toString export function is(val: unknown, type: string) { return toString.call(val) === `[object ${type}]` } export function isString(val: unknown): val is string { return is(val, 'String') } export function isNumber(val: unknown): val is number { return is(val, 'Number') } export function isBoolean(val: unknown): val is boolean { return is(val, 'Boolean') } export function isNull(val: unknown): val is null { return val === null } export function isUnDef(val?: T): val is T { return !isDef(val) } export function isDef(val?: T): val is T { return typeof val !== 'undefined' } export function isNullOrUnDef(val: unknown): val is null | undefined { return isUnDef(val) || isNull(val) } export function isObject(val: any): val is Record { return val !== null && is(val, 'Object') } export function isArray(val: any): val is Array { return val && Array.isArray(val) } export function isEmpty(val: T): val is T { if (isArray(val) || isString(val)) return val.length === 0 if (val instanceof Map || val instanceof Set) return val.size === 0 if (isObject(val)) return Object.keys(val).length === 0 return false } export function isDate(val: unknown): val is Date { return is(val, 'Date') } export function isPromise(val: unknown): val is Promise { return ( is(val, 'Promise') && isObject(val) && isFunction(val.then) && isFunction(val.catch) ) } export function isFunction(val: unknown): val is Function { return typeof val === 'function' } export function isFile(val: T | unknown): val is T { return is(val, 'File') } export function isRegExp(val: unknown): val is RegExp { return is(val, 'RegExp') } export function isWindow(val: any): val is Window { return typeof window !== 'undefined' && is(val, 'Window') } export function isElement(val: unknown): val is Element { return isObject(val) && !!val.tagName } export const isServer = typeof window === 'undefined' export const isClient = !isServer export function isUrl(path: string): boolean { const reg = /(((^https?:(?:\/\/)?)(?:[-;:&=\+\$,\w]+@)?[A-Za-z0-9.-]+(?::\d+)?|(?:www.|[-;:&=\+\$,\w]+@)[A-Za-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?\??(?:[-\+=&;%@.\w_]*)#?(?:[\w]*))?)$/ return reg.test(path) }