sankarsp/cypress-example-recipes

Various recipes for testing common scenarios with Cypress

Recipes

This repo contains various recipes for testing common scenarios using Cypress.

Recipe	Category	Description
Node Modules	Fundamentals	Import your own node modules
Single Sign On	Logging In	Log in across multiple servers or providers
HTML Web Forms	Logging In	Log in with a basic HTML form
XHR Web Forms	Logging In	Log in using an XHR
CSRF Tokens	Logging In	Log in with a required CSRF token
Tab Handling and Links	Testing the DOM	Links that open in a new tab
Hover and Hidden Elements	Testing the DOM	Test hidden elements requiring hover
Form Interactions	Testing the DOM	Test form elements like input type range
Drag and Drop	Testing the DOM	Use .trigger() to test drag and drop
Typescript with Browserify	Preprocessors	Add typescript support with browserify
Typescript with Webpack	Preprocessors	Add typescript support with webpack
Direct Control of AngularJS	Blogs	Bypass the DOM and control AngularJS
E2E API Testing	Blogs	Run your API Tests with a GUI
E2E Snapshots	Blogs	End-to-End Snapshot Testing
Codepen.io Testing	Blogs	Test a HyperApp Codepen demo
Testing Redux Store	Blogs	Test an application that uses Redux data store
Vue + Vuex + REST Testing	Blogs	Test an application that uses central data store
Stubbing Functions	Stubbing, Spying	Use cy.stub() to test function calls
Stubbing window.fetch	Stubbing, Spying	Use cy.stub() to control fetch requests
Stubbing methods called on window	Stubbing, Spying	Use cy.stub() for methods called on window
Stubbing Google Analytics	Stubbing, Spying	Use cy.stub() to test Google Analytics calls
Application Code	Unit Testing	Import and test your own application code
React with Enzyme	Unit Testing	Test your React components in isolation
File Upload in React	Unit Testing	Test file upload in React app
Adding Chai Assertions	Extending Cypress	Add new or custom chai assertions
Bootstrapping your App	Server Communication	Seed your application with test data
Seeding your Database in Node	Server Communication	Seed your database with test data
Environment variables	Fundamentals	Passing environment variables to tests

Overview

• This repo is structured similar to how other "Monorepos" work.
• Each example project has it's own Cypress configuration, tests, backend and frontend assets.
• Each of these example projects share a single "root" Cypress that is installed in the root node_modules folder.
• This structure looks different from normal projects, but its the easiest way to manage multiple projects without installing Cypress independently for each one.

Installation

## install all dependencies
npm install

## this will call 'npm start' on
## each example project's package.json
## which boots all of the webservers
npm start

## if you want to make modifications
## to the node server code and have
## the servers automatically restart
npm run dev

Opening Cypress GUI

## this opens the cypress test runner
## in the GUI mode. because this project
## is a monorepo - we've opened the test
## runner in 'global' mode.
##
## so to run a specific project you'll
## need to manually add the folder to Cypress.
npm run cypress:open

## alternatively, to open a specific
## example without running in global mode
cd ./examples/drag-n-drop
npm run cypress:open

Running from the CLI

## runs all example projects and
## exits with the total number of
## failures across all projects
npm run cypress:run

### runs all example projects in specific browser
### similar to cypress run --browser <name>
npm run cypress:run -- --browser chrome

### sends test results, videos, screenshots
### to Cypress dashboard
npm run cypress:run -- --record

### run single example by name
npm run cypress:run -- --example blogs__codepen-demo

## switch the browser to chrome instead
## of the default headless Electron browser
npm run cypress:run:chrome

## alternatively, to run a specific
## example without running all projects
cd ./examples/drag-n-drop
npm run cypress:run

Recipes

Node Modules

• Import ES2015 modules.
• Require CommonJS modules.
• Organize reusable utility functions.
• Import 3rd party node_modules.

Single Sign On

• Login when authentication is done on a 3rd party server.
• Parse tokens using cy.request().
• Manually set tokens on local storage.
• Map external hosts and point to local servers.

HTML Web Forms

• Test a standard username/password HTML form.
• Test errors submitting invalid data.
• Test unauthenticated redirects.
• Authenticate users with cookies.
• Create a custom cy.login() test command.
• Bypass needing to use your actual UI.
• Increase speed of testing with cy.request().

XHR Web Forms

• Test an AJAX backed username/password form.
• Test errors submitting invalid data.
• Stub JSON based XHR requests.
• Stub application functions.
• Create a custom cy.login() test command.
• Bypass needing to use your actual UI.
• Increase speed of testing with cy.request().

CSRF Tokens

• Use cy.request() to get around CSRF protections.
• Parse CSRF tokens out of HTML.
• Parse CSRF tokens out of response headers.
• Expose CSRF via a route.
• Disable CSRF when not in production.

Tab Handling and Links

• Test anchor links opening in new tabs: <a target="_blank">.
• Test anchor links that link to external domains: <a href="...">.
• Prevent content from opening in a new tab.
• Request external content that would open in a new tab using cy.request().
• Speed up tests by reducing loading times.

Hover and Hidden Elements

• Interact with elements that are hidden by CSS.
• Use .invoke() and .trigger() to simulate hovering.
• Trigger mouseover, mouseout, mouseenter, mouseleave events. Get around the lack of a .hover() command.

Form Interactions

• Use .invoke() and .trigger() to test a range input (slider).

Drag and Drop

• Use .trigger() to test drag-n-drop that uses mouse events.
• Use .trigger() to test drag-n-drop that uses drag events.

Typescript with Browserify

• Use @cypress/browserify-preprocessor to write Cypress tests in Typescript

Typescript with Webpack

• Use @cypress/webpack-preprocessor to write Cypress tests in Typescript
• Lint TypeScript spec code against Cypress type definitions

Direct Control of AngularJS

• Blog article written here
• Programmatically control AngularJS
• Bypass the DOM, update scopes directly
• Create custom command for controlling services

E2E API Testing

• Blog article written here
• Use cy.request() to perform API Testing
• Use the Cypress GUI to help debug requests

E2E Snapshots

• Blog post End-to-End Snapshot Testing
• Adding .snapshot() command by requiring 3rd party module
• Capturing and saving snapshots of primitive values
• Testing central data Vuex store using snapshots
• Making assertions against a DOM element with cy.get('...').snapshot()

Codepen Testing

• Blog post
• Load Codepen and get around iframe security restrictions.
• Use cy.request() to load a document into test iframe.
• Test HyperApp.js application through the DOM and through actions.

Testing Redux Store

• control application via DOM and check that Redux store has been properly updated
• drive application by dispatching Redux actions
• use Redux actions directly from tests
• load initial Redux state from a fixture file

Vue + Vuex + REST Testing

• Blog post
• Test a Vue.js web application that uses central data store
• Mock REST calls to the server
• Dispatch actions to the Vuex store
• Test text file upload

Stubbing Functions

• Use cy.stub() to stub dependencies in a unit test.
• Handle promises returned by stubbed functions.
• Handle callbacks in stubbed functions.

Stubbing window.fetch

• Use cy.spy() to verify the behavior of a function.
• Use cy.stub() to verify and control the behavior of a function.
• Use cy.clock() and cy.tick() to control time.
• Stub window.fetch to control server responses.
• Replace window.fetch with a polyfill that uses XHR and is loaded only for tests

Stubbing methods called on window

• Use cy.spy() to test window.open behavior.

Stubbing Google Analytics

• Use blacklistHosts to block Google Analytics from receiving requests.
• Use cy.stub() to verify that window.ga(...) was called with the correct arguments

Application Code

• Unit test your own application code libraries.
• Import modules using ES2015.
• Test simple math functions.
• Test the canonical fizzbuzz test.
• Automatically retry assertion until a given property inside an object:
  • is added or deleted
  • has expected value

React with Enzyme

• Unit test a React JSX Component using Enzyme.
• Import enzyme from node_modules.
• Extend chai assertions with chai-enzyme.

File Upload in React

• Passing synthetic test file to upload via an .trigger('change') event
• Stub remote server using cy.route()
• Alternatively stub axios.post method using cy.stub()

Adding Chai Assertions

• Extend chai with the chai-date-string assertion plugin.
• Extend chai with the chai-colors assertion plugin.
• Globally extend chai for all specs.

Bootstrapping your App

• Use cy.visit() onBeforeLoad callback.
• Start your application with test data.
• Stub an XHR to seed with test data.
• Wait on an XHR to finish.

Seeding your Database in Node

• Use cy.task() to communicate with node via the pluginsFile.
• Seed your database with test data.
• Wrap your pluginsFile so you can require files that use ES modules (import/export).

Environment Variables

• Pass values via env object in cypress.json.
• Pass any variable that starts with CYPRESS_.
• Extract any other variable from process.env using cypress/plugins/index.js callback.