Testing email with Cypress test email accounts

Cypress is a popular end-to-end testing framework for NodeJS. With the MailSlurp plugin you can test applications using real email addresses. MailSlurp is a free email account API with official support for Cypress. Here is a full example on how to test an web application sign up process using Cypress and MailSlurp:

See the guide on github

Disposable email addresses in Cypress JS

MailSlurp has an official plugin for CypressJS that allows you to create throwaway email inboxes on demand during tests.

npm install --save-dev cypress-mailslurp

Setup email client

MailSlurp is free but requires an API Key. Get yours by creating a free account. Set the environment variable CYPRESS_MAILSLURP_API_KEY or use the cypress.json file env property:

CYPRESS_MAILSLURP_API_KEY=your-api-key cypress run

Creating email inboxes

Create inboxes using the cy.mailslurp() method to obtain a mailslurp instance and then call instance methods such as createInbox.

cy.mailslurp()
    .then(mailslurp => mailslurp.createInbox())
    .then(inbox => expect(inbox.emailAddress).to.contain("@mailslurp"));

Example test

Here is an example that signs up for a user account on the demo app at playground.mailslurp.com

Here is the code using cypress in typescript:

/// <reference types="cypress-mailslurp" />
describe("user sign up test with mailslurp plugin", function () {
    // use cypress-mailslurp plugin to create an email address before test
    before(function () {
        return cy.mailslurp()
            .then(mailslurp => mailslurp.createInbox())
            .then(inbox => {
                // save inbox id and email address to this (make sure you use function and not arrow syntax)
                cy.wrap(inbox.id).as('inboxId')
                cy.wrap(inbox.emailAddress).as('emailAddress')
            })
    });
    it("01 - can load the demo application", function () {
        // get wrapped email address and assert contains a mailslurp email address
        expect(this.emailAddress).to.contain("@mailslurp");
        // visit the demo application
        cy.visit("https://playground.mailslurp.com")
        cy.title().should('contain', 'React App');
    });
    // use function instead of arrow syntax to access aliased values on this
    it("02 - can sign up using email address", function () {
        // click sign up and fill out the form
        cy.get("[data-test=sign-in-create-account-link]").click()
        // use the email address and a test password
        cy.get("[name=email]").type(this.emailAddress).trigger('change');
        cy.get("[name=password]").type('test-password').trigger('change');
        // click the submit button
        cy.get("[data-test=sign-up-create-account-button]").click();
    });
    it("03 - can receive confirmation code by email", function () {
        // app will send user an email containing a code, use mailslurp to wait for the latest email
        cy.mailslurp()
            // use inbox id and a timeout of 30 seconds
            .then(mailslurp => mailslurp.waitForLatestEmail(this.inboxId, 30000, true))
            // extract the confirmation code from the email body
            .then(email => /.*verification code is (\d{6}).*/.exec(email.body!!)!![1])
            // fill out the confirmation form and submit
            .then(code => {
                cy.get("[name=code]").type(code).trigger('change');
                cy.get("[data-test=confirm-sign-up-confirm-button]").click();
            })
    });
    // fill out sign in form
    it("04 - can sign in with confirmed account", function () {
        // use the email address and a test password
        cy.get("[data-test=username-input]").type(this.emailAddress).trigger('change');
        cy.get("[data-test=sign-in-password-input]").type('test-password').trigger('change');
        // click the submit button
        cy.get("[data-test=sign-in-sign-in-button]").click();
    });
    // can see authorized welcome screen
    it("05 - can see welcome screen", function () {
        // click sign up and fill out the form
        cy.get("h1").should("contain", "Welcome");
    });
});