js 用来判断数据类型的封装

const toString = Object.prototype.toString;

export function is(val, type) {
    return toString.call(val) === `[object ${type}]`;
}

export const isDef = val => {
    return typeof val !== 'undefined';
};

export const isUnDef = val => {
    return !isDef(val);
};

export const isObject = (val) => {
    return val !== null && is(val, 'Object');
};

export function isDate(val) {
    return is(val, 'Date');
}

export function isNull(val) {
    return val === null;
}

export function isNumber(val) {
    return is(val, 'Number');
}

export function isPromis(val) {
    return is(val, 'Promise') && isObject(val) && isFunction(val.then) && isFunction(val.catch);
}

export function isString(val) {
    return is(val, 'String');
}

export const isFunction = (val) => typeof val === 'function';

export function isBoolean(val) {
    return is(val, 'Boolean');
}

export function isRegExp(val) {
    return is(val, 'RegExp');
}

export function isArray(val) {
    return val && Array.isArray(val);
}

export const isClient = () => {
    return typeof window !== 'undefined';
};

export const isWindow = (val) => {
    return typeof window !== 'undefined' && is(val, 'Window');
};

export const isElement = (val) => {
    return isObject(val) && !!val.tagName;
};

export const isServer = typeof window === 'undefined';

export function isImageDom(o) {
    return o && ['IMAGE', 'IMG'].includes(o.tagName);
}

export function isExternal(path) {
    return /^(https?:|mailto:|tel:)/.test(path)
}