Cypress vs Selenium: The best tool for code testers

What is Cypress?

Cypress is an open-source test automation tool. The Cypress framework, a NodeJS-based modern automation tool supports JavaScript-Typescript. One can test anything, whether a web application or other technology, that runs on a web browser with Cypress. Any language that allows for file transfer through Javascript can be easily tested.  

Features of Cypress

• Testing of all kinds; end-to-end, unit, integration & more.
• Browsers supported by Cypress include Chrome, Firefox, Edge, Electron, Brave & more. 

Cypress also supports direct interaction with browsers without dependency on browser drivers, along with cross-browser testing.

• Automated screenshots of the application during the test case run via an aptly named feature, Time Travel. 
• The ability to inspect the application element's state both before and after a command has been executed.
• Two modes of test execution; GUI mode & Command line mode.
• An inbuilt wait feature to add explicit wait instructions when using assertion.

Limitations of Cypress

• Cypress cannot use two browsers at the same time.
• Multi-tabs isn't supported.
• Only JavaScript can be used to create test cases
• Safari and IE are not supported at the moment.
• Limited support for I Frames

What is Selenium?

Selenium is a test automation tool that automates web browsers. Combining the Selenium WebDriver library with a language-specific framework enables QA to automate test cases for the chosen browser. The choice of programming language is up to the developers and includes Ruby, Python, Java, and other languages. 

The WebDriver uses JSON wire protocol for the execution of test cases. Execution primarily consists of three main steps, namely-

1. Test commands are converted into a URL
2. The HTTP server is used by browser drivers to receive these URLs
3. The URLs are passed on to the actual browsers as a request

For a more detailed explanation of Selenium WebDriver’s architecture, read...

Features of Selenium

• Compatible with multiple operating systems, like Windows, Linux, Mac & more.
• Programming languages like Java, Ruby, Python, and other options are readily available for selection.
• Compatible with multiple modern browsers like Safari, Chrome, Firefox, etc.
• Powerful & concise APIs.

Limitations of Selenium

• No in-built command for an automatic generation of the test results.
• Handling page load or element load is difficult with selenium.
• Limited support for testing images.
• Creating test cases is time-consuming
• Difficult to set up a test environment 

Cypress vs Selenium: Core Differences

Selenium vs Cypress: The utility of both tools for test automation

Although Selenium and Cypress are both designed for browsers for testing, they differ considerably in terms of architecture and performance.

A key difference is that Cypress as a tool is ideal for introducing developers to test automation while Selenium is more of a general-purpose tool.

Cypress is preferred over Selenium when one needs:

• Single Framework for component, API, visuals, accessibility, performance testing.
  Video recording capability of test execution.
• Out-of-the-box retrial capability of actions performed over elements, making tests more reliable.
• Single programming language for development and automation.
• Capability to Mock/Stub requests and responses during the early stages of development.
• Save time building a framework from scratch with a stable and ready-to-use framework with everything wrapped and ready-to-use functions.
• A test Runner which provides time travel capability to go through individual steps with before and after screenshots attached to debug failures.

Selenium is preferred over Cypress when one needs:

• Flexibility in terms of choosing the test script language. 
• Test cases to run on different browsers simultaneously. 
• Cross-browser testing at scale.
• Support for NUnit and JUnit testing framework.    

Cypress's sole reliance on JavaScript demonstrates that it was tailor-made for front-end developers. Proficiency in JavaScript is advised before getting started with Cypress testing.

Cypress and its architecture empower testers with the ability to perform Test-Driven Development (TDD) and testing as a parallel process.