Testing User Sign-Up and Email Confirmation — how to extract MFA tokens during automated testing.

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How can we test applications that rely on email confirmation? MailSlurp is a free API that makes that possible.

Email testing APIs

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An example project

Testing user sign-up

What does our app look like?

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A demo application for testing

Testing with MailSlurp

Project setup

mkdir signup && cd $_
echo '{}' > package.json
npm install --save mailslurp-client

Add a test framework

npm install --save @wdio/cli @wdio/local-runner @wdio/mocha-framework @wdio/selenium-standalone-service
npm install --save chromedriver wdio-chromedriver-service

Configure Webdriver

const config = {
runner: "local",
path: "/",
specs: ["test/*.test.js"],
exclude: [],
maxInstances: 10,
capabilities: [
maxInstances: 5,
browserName: "chrome",
logLevel: "info",
bail: 0,
baseUrl: "https://playground.mailslurp.com",
waitforTimeout: 30000,
connectionRetryTimeout: 90000,
connectionRetryCount: 3,
framework: "mocha",
services: ["chromedriver"],
reporters: ["spec"],
mochaOpts: {
ui: "bdd",
timeout: 60000,

exports.config = config;

Add a test command

"scripts": {
"test": "wdio wdio.conf.js"
"dependencies": {
"@wdio/cli": "^5.13.2",
"@wdio/local-runner": "^5.13.2",
"@wdio/mocha-framework": "^5.13.2",
"@wdio/selenium-standalone-service": "^5.13.2",
"@wdio/spec-reporter": "^5.13.2",
"chromedriver": "^78.0.1",
"mailslurp-client": "^6.5.0",
"wdio-chromedriver-service": "^5.0.2"

Writing a test

mkdir test
touch test/sign-up.test.js

Defining test requirements

Special needs (why we use a email testing API)

Generating test email accounts

const MailSlurp = require("mailslurp-client").default;
const apiKey = process.env.API_KEY;
const mailslurp = new MailSlurp({ apiKey });
const { emailAddress, id } = await mailslurp.createInbox();

Testing user sign-up with disposable email addresses

const assert = require("assert");

describe("sign up page", () => {
it("can load playground app", async () => {
await browser.url("/");
await browser.setWindowSize(1200, 1200);
it("can load the sign-up section", async () => {
await $('[data-test="sign-in-create-account-link"]').then((e) => e.click());
await $(".sign-up-header-section")
.then((e) => e.getText())
.then((text) => assert.strictEqual(text, "Testable Sign Up Form"));
API_KEY=your-mailslurp-api-key npm run test
[chrome  linux #0-0] Running: chrome on linux
[chrome linux #0-0]
[chrome linux #0-0] sign up page
[chrome linux #0-0] ✓ can load playground app
[chrome linux #0-0] ✓ can load the sign-up section
[chrome linux #0-0]
[chrome linux #0-0] 2 passing (607ms)

Spec Files: 1 passed, 1 total (100% completed) in 00:00:01

Signing up

let inbox;
let password = "test-password";

it("can sign-up with test email account", async () => {
// create a new email address for the test run
inbox = await mailslurp.createInbox();

// fill out and submit the new user form
await $('[name="email"]').then((e) => e.setValue(inbox.emailAddress));
await $('[name="password"]').then((e) => e.setValue(password));
await $('[data-test="sign-up-create-account-button"]').then((e) => e.click());
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Capturing email confirmation code in tests

it("can fetch confirmation code", async () => {
// fetch the email from mailslurp
const email = await mailslurp.waitForLatestEmail(inbox.id);

// verify that it contains the code
assert.strictEqual(/verification code is/.test(email.body), true);

// extract the confirmation code
code = /([0-9]{6})$/.exec(email.body)[1];

it("can enter confirmation code and confirm user", async () => {
await $('[name="code"]').then((e) => e.setValue(code));
await $('[data-test="confirm-sign-up-confirm-button"]').then((e) =>
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\code = /([0-9]{6})$/.exec(email.body)[1];

Logging in with confirmed account

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it("can log in with confirmed account", async () => {
// assert we see the sign in form
await $('[data-test="sign-in-header-section"]')
.then((e) => e.getText())
.then((text) => assert.strictEqual(text, "Sign in to your account"));

// fill out username (email) and password
await $('[name="username"]').then((e) => e.setValue(inbox.emailAddress));
await $('[name="password"]').then((e) => e.setValue(password));

// submit
await $('[data-test="sign-in-sign-in-button"]').then((e) => e.click());

it("shows the successful greeting", async () => {
await $('[data-test="greetings-nav-bar"]')
.then((e) => e.getText())
.then((text) => assert.strictEqual(/Hello/.test(text), true));

In summary

Code samples

Test Email API for end-to-end with real email addresses. Support for NodeJS, PHP, Python, Ruby, Java, C# and more. See https://www.mailslurp.com for details.

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