What is Cypress?
Cypress is an open-source, full-featured, and easy-to-use end to end testing framework for web application testing. Cypress is a relatively new player in the automation testing space and has been gaining a lot of traction lately, as evident from the number of Forks (2.2K) and Stars (36.6K) for the project.
If you’re a developer looking to automate the testing of your application, this Cypress testing tutorial walks through the basics of Cypress, how to use it for end-to-end testing, and more.
Note: You can run Cypress testing over the LambdaTest cloud.
Cypress is a comparatively new testing platform that aims to overcome the challenges of automated frontend testing for applications built with React and AngularJS. It's a quick, easy and reliable tool for testing these applications by running them in their actual browser environments. Since Cypress executes tests on a real browser instance, you wouldn't need to download browser drivers, unlike Selenium.
Check out The State of JS 2021 Cypress testing data on the basis of developer Satisfaction,Interest, Usage and Awareness.
Satisfaction: Since 2019, Cypress has shown a slight dip in the level of satisfaction for developers. Cypress shows a dip from 93% in 2019 to 92% in 2021.
Interest: The interest shown by the developers for using Cypress testing framework has also shown a fall from 76% in 2019 to 72% in 2021.
Usage: The State of JS 2021 survey shows a significant rise in terms of usage from 26% in 2019 to 43% in 2021.
Awareness: As per the State of JS 2021 survey, there is a significant rise in the awareness of the Cypress framework amongst the developers from 63% in 2019 to 83% in 2021.
Under the Experience Over Time section of the State of JS 2021 survey, it also shows:
For 2019: Around 28.5% of developers have shown interest in using Cypress for their testing needs. The lack of awareness of the Cypress framework is at an all-time high i.e., 36.9%. Along with this, only 23.9% of developers would like to use Cypress again in the future.
For 2020: The developer interest in using the Cypress testing framework has shown a slight increase as compared to the previous year and now represents 29.9%. There is a significant decrease in the lack of awareness for the Cypress testing framework and is now at 26.2% only. Along with this, the percentage of developers and testers who would like to use Cypress again has significantly increased from 23.9% to 32.9%.
For 2021: The developer interest in using the Cypress testing framework is stagnant for this year. The awareness for the Cypress framework among the developers and testers has significantly increased over the past 3 years. Along with this, the percentage of developers and testers who would like to use Cypress again is at an all-time high of 39.1%.
2. Fast to Setup: Cypress has no additional requirements for a standard installation. You do not need any libraries, testing engines, servers, drivers or wrappers. Cypress doesn’t require configuration or additional choices to be made.
The debugging process in Cypress is streamlined and simple. With native access to every single object, you can easily analyze errors within your application. You can debug your application directly with Chrome DevTools while the tests are being executed in the browser.
4. Fast to Execute: Cypress provides a fast, easy, and reliable way to test your application. It automatically waits for the DOM to be loaded so you don’t have to implement additional waits or set up explicit or implicit waits. Cypress follows everything that happens in your application synchronously—it knows when the page is being loaded and when elements send events.
Cypress tests run inside the browser, allowing Cypress to modify the browser's behaviour by listening to the incoming network requests and altering them on the fly. In addition, cypress tests have a lower flakiness rate than Selenium tests since Cypress does not use WebDriver. Instead, spies and stubs can be used at run time to control the behaviour of functions and times. Now, let's look at Cypress architecture.
As of the time of writing, Cypress supports Chrome-family browsers (including Electron and Chromium-based Microsoft Edge) and Firefox.
Selenium’s architecture uses the WebDriver component to communicate with the Browser Driver, which then interacts with the actual browser. The WebDriver routes communications between all its components, making sure that information can flow back to the WebDriver from the actual browser. Developers will need different Browser Drivers for different types of browsers.
On the other hand, Cypress executes tests inside the browser, making it possible to test code in real time as it runs in the browser. Cypress runs on a server process, which makes it possible for Cypress to execute code in the same run loop as the application. Cypress, the test runner created by Facebook, is able to respond to application events in real-time because it constantly communicates with the server process. This also allows Cypress to interact with OS components for tasks outside of the browser, such as taking screenshots.
Cypress support the following browsers:
Here is the list of browsers supported by LambdaTest for running Cypress test scripts.
With the newer versions of Cypress releasing, to gain the most from recent improvements and bug fixes, it is recommended that your test scripts use the latest version. The .latest format defines the Cypress versions, ensuring that your test scripts always use the latest minor version.
LambdaTest uses the latest minor version to run the tests when Cypress versions are set as 6, 7, 8 or 9. LambdaTest provides support for all the version, starting from - 6.0.0 to 9.2.0.
Write and execute your code at lightspeed with the help of LambdaTest Cypress examples code index.
|Browser Support||Chrome, Firefox, Internet Explorer, Microsoft Edge, Safari||Brave, Chrome, Edge, Firefox, Electron|
|Test Frameworks||PyUnit, JUnit, TestNG, JBehave, Behave, Gauge, Specflow, NUnit, Robot, and more.||Mocha JS|
|Test Setup||Selenium Grid Server and browser drivers have to be installed in the test machine. Setup is different for a cloud-based Selenium Grid where only browser drivers have to be installed on the test machine.||Node JS, Mocha JS, and Cypress have to be installed on the test machine.|
|Area of Testing||Unit testing, security testing, and integration testing.||Unit testing, security testing, and integration testing|
|Integrations||Wide range of integration options – CI/CD tools, reporting tools, and more.||Limited integration support with CI/CD tools when compared to Selenium.|
|Driver Dependencies||Appropriate browser driver has to be installed so that the test script can talk to the corresponding web browser.||No driver dependency.|
|Multiple Browser Instances||Supported||Not Supported|
|Execution Speed||Slow||Fast as Cypress scripts are executed within the browser.|
|Time Travel||Not Supported||Supported|
|Real-time Reloads||Not Supported||Tests are reloaded when any change is made in the test implementation.|
|Automatic Waiting||Not Supported||No requirement to add waits or sleep in the tests. Cypress automatically waits for commands and assertions before moving to the next instruction.|
|Default Screenshots and Videos||Not available by default, the developer has to write code to achieve the same.||Available by default.|
|Network Traffic Control||Not Supported||No network lag as tests are executed within the browser. You can control, stub, and test edge cases without any involvement of the server.|
|Access to Elements Outside the DOM||Access only to the elements in the DOM.||A unique DOM manipulation technique helps Cypress in getting access to DOM elements, timers, service workers, and more.|
|Documentation and Community||Mature Community with multiple points of support. Average Documentation.||Growing Community, Excellent Documentation.|
|Remote Execution||Supported. Cloud-based Selenium Grid from LambdaTest can be used to expedite cross-browser testing and automation testing.||Not Supported|
|Spies, Stubs, and Clocks||Not Available||Cypress lets you control the behaviour of functions, timers, and server responses with ease.|
|Mobile Testing||Mobile Testing with Appium||Not Supported|
|Test Flakiness||Tests can be flaky.||With Cypress, tests are expected to be non-flaky.|
After working with Cypress UI testing, here are some of the best practices you should use to avoid anti-patterns in your Cypress automation tests:
1. Login Programmatically: To test most of the functionalities, a user needs to be logged in.
A very common mistake made by testers is that they often log in to a web page that requires authentication and then redirect to the page that needs testing. But the problem with this approach is that it uses your application UI for authentication, and after the authentication is done, it redirects to the page you want.
The way to deal with this would be to log in programmatically. To sign in programmatically, we need to use the Cypress request command cy.request(). This command makes HTTP requests outside of the browser and can bypass CORS restrictions and other security measures.
2. Using Best-suited Selectors: All tests we write should include selectors for elements. CSS classes may change or be removed, so we must use resilient selectors that can accommodate those changes.
The Selector Playground follows these best practices automatically. It prefers elements with data-cy data-test when determining a unique selector because it has the highest priority. We should use data-cy to keep consistency.
When to use cy.contains()?
When you need to select an element with the text present in the page, you can use cy.contains(). However, you must ensure that the selected text always exists.
3. Assigning Commands Return Values: Cypress does not run synchronously, meaning that the return value of any command cannot be assigned to a variable.
Do not assign the return values of any Cypress command. Enqueueing commands makes them asynchronous, so there is no guarantee that the behavior of the tests will be the same if they depend on the return values.
4. Having Tests Independent of Each Other:
The approach to testing your code depends on the previous state of the application. For example, the step of .should(“contain”, “Hello World”) depends on the previous step of clicking the button, and this also depends on the previous state of typing in the input. These steps obviously depend on each other and fail completely in isolation.
5. Avoiding Small Tests With Single Assertion: Cypress is different from running unit tests, which only run a single event at a time, resetting the state between each one.
Adding multiple assertions to a single test is much faster than creating multiple tests; therefore, you should not be afraid to add multiple assertions to a single test.
6. Using after or afterEach hooks:
It is a good idea to wait until after your test ends to write your state clean-up code. This will help you avoid introducing unnecessary failing tests and will speed up your testing performance.
Automated testing is an essential part of modern software delivery practices. The need for stable test automation tools has also increased with the increasing demand for quick time-to-market and stable products. Cypress has successfully established its place among other testing frameworks in web automation and end-to-end UI test automation.
Being an open-source framework, Cypress serves as a lifeline to many freelancer web developers & web testers. A cloud-based Cypress UI testing cloud-like LambdaTest solves the problems mentioned above.
LambdaTest is a leading test execution and orchestration platform that is fast, reliable, scalable, and secure. It allows users to run both manual testing and automated testing of web and mobile apps across 3000+ different browsers, operating systems, and real device combinations.
Using LambdaTest, businesses can ensure quicker developer feedback and hence achieve faster go to market. Over 500 enterprises and 1 Million + users across 130+ countries rely on LambdaTest for their testing needs.
Cypress cloud grids like LambdaTest allow you to perform Cypress testing at scale. LambdaTest allows you to perform automated cross browser testing on an online browser farm of 40+ browsers and operating systems to expedite the test execution in a scalable way. Moreover, it increases the test coverage with better product quality.
To run your first Cypress automation testing script online, refer to our detailed support documentation & GitHub repository. No need to worry about the challenges with Cypress infrastructure. Want to know a fun fact? Your first 100 Cypress automation testing minutes are on us with just a free sign-up. You can also avail benefits of manual cross-browser testing, responsive testing, and more with a lifetime of free access to LambdaTest, the world's fastest-growing cloud Cypress Grid.
Our detailed documentation will help you develop a better functional understanding of the Cypress framework. We also have Cypress Tutorials on our blog page. Finally, kick-start your Cypress UI automation journey by running your first Cypress test script on the LambdaTest cloud.
Run your first Cypress test with our detailed blogs and video tutorials:
Cypress executes tests directly in the browser. It runs on a server process that powers Cypress to run in the same run loop as your application, so you can be sure that your tests are not slowing down your app. Along with this, Cypress is fundamentally and architecturally different from Selenium, which means you can write faster, easier and more reliable tests.
Cypress is a great way to test functional applications in the browser. Cypress allows us to create our tests while our application is being developed and runs on all platforms. It gives a fast, easy-to-use debugging platform for all development activities.
Cypress makes it easy to use the Dev Tools while tests run. You can see every console message, every network request, and even time travel back to the state your application was in when commands ran.