Code snippet used in an IoC blog post

sendSms-traditional.js

import _ from "lodash"
import { isValidPhone } from "../validation/phone"
import template from "./template"
import { DbConn } from "../Db"
import SmsService from "../SmsService"

const createMessage = _.template(template)

export const sendSms = userId => {
    const service = new SmsService()

    return DbConn.User.byId(userId)
        .then(throwIfInvalidPhone)
        .then(createMessage)
        .then(message => service.send(message, user.phone))
        .then(() => ([ userId, message ]))
}

const throwIfInvalidPhone = user => {
    if (!isValidPhone(user.phone)) {
        throw new Error(`Invalid phone for user ${ userId }.`);
    }

    return user
}