Mandrill API mocking in Nodejs

README.md

A simple way to mock calls to the Mandrill API from nodejs tests. It uses the amazing mockery package.

mandrill-mock.js

const mockery = require('mockery')

const mandrillApiMock = (function mandrillApiMock() {
    let sentMail = [];
    let mandrillOptions;

    function Mandrill(options) {
        mandrillOptions = options;
        this.messages = {
            send: function(data, success, failure) {
                sentMail.push(data);
                success(null, data);
            }
        };
    }

    return {
        Mandrill,
        mock: {
            sentMailCount: () => {
                return sentMail.length;
            },
            sentMail: () => sentMail,
            reset: () => {
                sentMail = [],
                mandrillOptions = null;
            },
            getOptions: () => {
                return mandrillOptions;
            }
        }
    }
}());

before(function(){
    
    // Enable mockery to mock objects
    mockery.enable({
        warnOnUnregistered: false
    })
    
    // Once mocked, any code that calls require('nodemailer') will get our nodemailerMock
    mockery.registerMock('mandrill-api/mandrill', mandrillApiMock)
    
    // Make sure anything that uses nodemailer is loaded here, after it is mocked...
    
})

afterEach(function(){
    
    // Reset the mock back to the defaults after each test
    mandrillApiMock.mock.reset()
    
})

after(function(){
    
    // Remove our mocked nodemailer and disable mockery
    mockery.deregisterAll()
    mockery.disable()
    
})