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MailSlurp Cypress Plugin

Official MailSlurp email plugin for Cypress JS. Create real test email accounts. Send and receive emails and attachments in Cypress tests. For more advanced usage see the standard MailSlurp library.

Install Cypress

First install and initialize Cypress:

npm install --save-dev cypress

Set command timeouts in your cypress.config.js

import { defineConfig } from 'cypress'

export default defineConfig({
// set timeouts so MailSlurp can wait for emails and sms
defaultCommandTimeout: 30000,
responseTimeout: 30000,
requestTimeout: 30000,
e2e: {
// We've imported your old cypress plugins here.
// You may want to clean this up later by importing these.
setupNodeEvents(on, config) {
return require('./cypress/plugins/index.js')(on, config)
},
// examples run against the playground app
baseUrl: 'https://playground.mailslurp.com',
// these examples require no test isolation
testIsolation: false
},
})

Install MailSlurp

Next we add MailSlurp to our Cypress tests. There are two ways to use MailSlurp with Cypress:

  • either with the cypress-mailslurp plugin
  • or by adding a command to register the mailslurp-client within your cypress/support/commands.js file.

1) Cypress MailSlurp Plugin

npm install --save-dev cypress-mailslurp

Then include the plugin in your cypress/support/index.{js,ts} file.

import {MailSlurp} from "mailslurp-client";

NOTE you must import the MailSlurp plugin in cypress/support/e2e.ts

2) Standalone MailSlurp client

Install the MailSlurp Javascript library and then add MailSlurp as a custom cypress command.

Install package from npm:

npm install --save-dev mailslurp-client

Edit one of the custom commands files cypress/support/commands.{ts,js} or cypress/support/e2e.{ts,js} and register the MailSlurp command:

// read the API Key from environment variable (see the API Key section of README)
const apiKey = Cypress.env('MAILSLURP_API_KEY');
if (!apiKey) {
throw new Error(
'Error no MailSlurp API Key. Please set the `CYPRESS_MAILSLURP_API_KEY` ' +
'environment variable to the value of your MailSlurp API Key to use the MailSlurp Cypress plugin. ' +
'Create a free account at https://app.mailslurp.com/sign-up/. See https://docs.cypress.io/guides/guides/environment-variables#Option-3-CYPRESS_ for more information.'
);
}
// create an instance of mailslurp-client
const mailslurp = new MailSlurp({ apiKey, basePath: 'https://cypress.api.mailslurp.com' });
// register MailSlurp with cypress under "mailslurp" command
// afterwards you can access it in tests using `cy.mailslurp().then(mailslurp => /* do stuff */)`
Cypress.Commands.add('mailslurp' as any, () => {
return Promise.resolve(mailslurp);
});

Setup

MailSlurp is free but requires an API Key. Get yours by creating a free account.

See the example project for setup help.

API Key

Set the environment variable CYPRESS_MAILSLURP_API_KEY or use the cypress.json file env property:

Environment variable

For Mac/Linux set the CYPRESS_MAILSLURP_API_KEY environment variable:

CYPRESS_MAILSLURP_API_KEY=your-api-key cypress run

For Windows machines use the Powershell format $env:CYPRESS_MAILSLURP_API_KEY

$env:CYPRESS_MAILSLURP_API_KEY=your-api-key;
cypress run;

Cypress env property

You can also configure Cypress using the config format.

{
"env": {
"MAILSLURP_API_KEY": "your-mailslurp-api-key"
}
}

Timeouts

MailSlurp requires timeouts to wait for inbound emails. Set timeouts in cypress.json:

{
"defaultCommandTimeout": 30000,
"responseTimeout": 30000,
"requestTimeout": 30000
}

Typescript support

MailSlurp adds the mailslurp command to the Cypress cy object. Include the type definition reference comment in your test file or support index.ts:

/// <reference types="cypress-mailslurp" />

Or define the type yourself like so:

import { MailSlurp } from "mailslurp-client";

declare global {
namespace Cypress {
interface Chainable {
mailslurp: () => Promise<MailSlurp>;
}
}
}

Usage

The Cypress MailSlurp plugin provide one simple command attached to the Cypress object: cy.mailslurp(). This method returns a MailSlurp client instance that has all the same methods and properties as the official MailSlurp client. Use the command with the then() method to access the instance:

cy.mailslurp().then(mailslurp => mailslurp.createInbox() /* etc */)

You can test that you have setup MailSlurp correctly in a test like so:

describe('basic usage', function () {
it('can load the plugin', async function () {
// test we can connect to mailslurp
const mailslurp = await cy.mailslurp();
const userInfo = await mailslurp.userController.getUserInfo();
expect(userInfo.id).to.exist
})
});
describe('store values', function () {
//<gen>cy_store_values
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('can access values on this', function() {
// get wrapped email address and assert contains a mailslurp email address
expect(this.emailAddress).to.contain('@mailslurp');
});

Common methods

The client chained by the cy.mailslurp() has all the same methods and properties as the official MailSlurp client. See the Javascript documentation for a full API reference or see the examples below.

The MailSlurp client has a number of convenience methods and also exposes the full MailSlurp API as controllers. See the class reference for full method documentation.

Create email address

You can create test email accounts with MailSlurp by creating inboxes. Inboxes have an id and an emailAddress. Save the id for later use when fetching or sending emails.

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

Receive emails in tests

Use the waitFor methods to wait for emails for an inbox. See the email object docs for full properties.

cy.mailslurp()
.then(mailslurp => mailslurp.waitForLatestEmail(undefined,undefined,inboxId,undefined,undefined, 30000, true))
.then(email => expect(email.subject).to.contain("My email"))

Send emails

To send emails in Cypress tests first create an inbox then use the sendEmail method.

cy.mailslurp()
.then(mailslurp => mailslurp.sendEmail(inboxId, { to: ['test@example.com'], subject: 'test', body: '<html></html>', isHTML: true }))

Accessing more methods

To access all the MailSlurp methods available in the REST API and Javascript Client use the controllers on the mailslurp instance.

cy.mailslurp().then(mailslurp => mailslurp.attachmentController.uploadAttachment({
base64Contents: fileBase64Encoded,
contentType: 'text/plain',
filename: basename(pathToAttachment)
}))

Storing values between tests

Cypress has a unique async nature. To use MailSlurp effectively with Cypress chain your commands using then() or store results in wrapped aliases using wrap() and as().

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('can access values on this', function() {
// get wrapped email address and assert contains a mailslurp email address
expect(this.emailAddress).to.contain('@mailslurp');
});

Note: using wrap to store values across test methods requires you to use function syntax instead of () => arrow syntax. This ensure that this is dynamically scoped and includes the aliased variables.

Example test

Here is an example of testing user sign up on a demo application hosted at playground.mailslurp.com. It creates a new MailSlurp inbox before all tests and saves the inbox.id and inbox.emailAddress to a shared text context using the cy.wrap().as() methods. It then loads the demo application, fills out a sign up form using the email address and receives a user confirmation code. We wait for the email to arrive using the waitForLatestEmail method and then extract a confirmation code that can be submitted to the app to confirm the user.

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('/');
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');
});
});

More examples

See the Cypress example test suite for real tests that use this plugin.