validator.js

/**
 * Chek if email is valid
 * @prop String email
 * @returns Boolean
 */
export const isEmail = (email) => {
    const re = /^(([^<>()[\]\\.,;:\s@"]+(\.[^<>()[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
}

/**
 * Chek if vatiable is empty
 * @prop String thing
 * @returns Boolean
 */
export const isEmpty = (thing) => {
    let empty = false;

    switch (typeof thing) {
        case 'undefined':
            empty = true;
            break;
        case 'string':
            if (thing.trim().length === 0) {
                empty = true;
            }
            break;
        case 'object':
            if (thing === null) {
                empty = true;
            } else if (Object.keys(thing).length === 0) {
                empty = true;
            }
            break;
        default:
            empty = true;
    }

    return empty;
}

/**
 * Check length of the string greater than
 * @prop String|Integer str
 * @prop boolean|options.trim Trim input before validating
 * @prop number|options.lt Check if length less than lt
 * @prop number|options.lte Check if length is less than or equals to lte
 * @prop number|options.gt Check if length is greater than gt
 * @prop number|options.gte Check if length is greater than or equals to gte
 * @returns Boolean
 */
export const isLength = (str, options) => {

    if (isEmpty(options)) {
        throw new Error("Who will provide the options you?")
    }

    let isValid = true;

    if (['string', 'number'].indexOf(typeof str) === -1) {
        isValid = false;
    } else {
        // Convert to string incase it's number
        let len = 0;

        if(options.trim){
            len = str.toString().trim().length;
        } else {
            len = str.toString().length;
        }