Cypress vs. Puppeteer: A Detailed Comparison
Cypress and Puppeteer have similar tools for testing web application testing, and their detailed comparison is the main focus of this blog.
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The availability of various tools in the market has often kept you thinking about which tool is appropriate for testing the web application. It is important to test the web application to ensure that it functions as per the user’s requirement and gives a high-end user experience. End-to-end testing is an approach that is designed to ensure the functionality of the applications by automating the browsers to run the scenario of particular actions made by end users.
To accomplish this, Cypress and Puppeteer have commonly used tools, and their detailed comparison is the main focus of the blog. The use of Cypress has increased in the recent year for web automation testing addressing issues faced by modern web applications. Now, Puppeteer is also widely accepted for web automation testing. This triggered debate on Cypress vs. Puppeteer. To have a piece of good information on the testing tools and Cypress vs. Puppeteer’s detailed comparison is crucial.
Let’s get started with discussing the overview of Cypress and Puppeteer
What Is Cypress?
It also supports the Mocha test framework. The working of Cypress is different from other testing tools. For example, when you need to run a script inside the browser, it is mainly executed in the same loop as that of your application. However, when its execution needs to be done outside the browser for the same scripts, it leverages the Node.js server to support it.
Features of Cypress
Some of the exciting features of Cypress that you should know are as follows:
· It takes snips of snapshots during the running of the tests.
· It allows real-time and fast debugging by using tools like Developer Tools.
· It has automated waiting, so you do not have to add waits or sleep to the running tests.
· You can verify and manage the behavior of the functions, timers, and server response.
· It effortlessly controls, test, and stub the edge cases without involving the servers.
What Is Puppeteer?
It is an open-source node js library-based framework used for automation testing and web scraping tools. It gives high-level API to control Chromium and Chrome, which runs headless by default.
Puppeteer is very easy to use by the testers as it is based on the DevTools Protocol, which is similar to the one used by the Chrome Developer Tools. You need to be aware of the Chrome Developer Tools to ensure running with Puppeteer quickly.
Cypress vs. Puppeteer
The comparison between the Cypress vs. Puppeteer is made below based on highlighting aspects that will help you get a clear picture.
A puppeteer is a tool which is developed by Google which works for automating Chrome with the use of DevTool protocol. However, Cypress is developed by Semiconductors which is a test runner-open source. The main difference between Puppeteer and Cypress is based on their work.
Puppeteer is basically allowing browser automation based on node library, whereas Cypress is purely a test automation framework allowing End-to-End Testing, Integration Testing, and Unit Testing. It could better be understood that Puppeteer is not a framework but just a chromium version of the node version, which provides browser automation for Chrome and Chromium.
The running is executed headless by default which can be further configured to run full Chromium or Chrome. In addition, Puppeteer is such a tool that provides a high level of API for controlling Chrome and Chromium over the DevTool protocol. Relating this to Cypress, it is mainly a front-end testing tool that is built for the modern web. Lastly, Puppeteer is free to use, whereas Cypress comes with both free and paid versions.
Types of Testing
Comparing the testing done by Cypress and Puppeteer, Cypress gives you wider options. For example, if you are looking the testing an entire application, Puppeteer cannot be the best option. It is basically great for web scrapping and crawling SPA. However, Cypress is a tool through which you can do End-to-end tests, Unit tests, and integration tests, and it can test anything that runs in a browser.
Puppeteer is mainly used for automating UI testing, mouse and keyboard movement, and others. It basically tests the application developed in Angularjs and Angular. Like Cypress, it is not considered an automation tool but rather manages the internal aspects of the chromium browser. It is a development tool that is able to perform tasks by developers, like locating elements and handling requests and responses.
Cypress and Puppeteer differ in their architecture. Generally, most of the testing tools work by running outside of the browser, which is executed remote commands across the network. Cypress-testing tools operate inside the browsers which execute the test codes. It allows Cypress to listen and verify the browser performance at run time by modifying DOM and altering network requests and responses on the fly.
It does not require any of the driver binaries. It runs on a NodeJS server which associates with the test runner manipulated by Cypress to operate the application and test code which is another iframe in a similar event loop. The supported browser of Cypress includes Canary, Chromium, Microsoft Edge, Mozilla Firefox browsers, and electron.
Relating to the Puppeteer architecture follows the DevTools protocol as mentioned above. It manages the Chromium and chrome browser with the aid of high-quality API given by the Node library.
Comparing the testing speed of the Puppeteer and Cypress, Puppeteer is regarded to be much faster than Cypress. In using Cypress, the test scripts are executed in the browser, where you need to click on a particular button. This will not send the command to involve a specific driver to the browser but rather utilizes DOM events to send the click command to the button. However, Puppeteer has great control over the browser due to high-level API control over Chrome and Chromium. Further, it works with minimal settings, eliminates extras, and uses less space than Cypress, making them consume less memory and start faster.
Cypress is slower when executing the run test in a larger application. The main reason is that it tends to take snips of the application state at a different point in time of the tests, which makes it take more time. However, such cases are not evident in the Puppeteer, which makes it faster than Cypress.
Reliability and Flexibility
Nevertheless, Puppeteer can be a great option for quick testing; however, when we want to test the entire performance and functionality of application testing, it is better suggested to use a stronger tool like Cypress. The main reason is that Cypress has its individual assertion, but Puppeteer does not, and rather it is based on Mocha, Jasmine, or Jest frameworks. Further, Cypress has its individual IDE, and Puppeteer is dependent on the VS Code and Webstorm. In a nutshell, Puppeteer only supports Chromium engine-based browsers, whereas Cypress supports many different browsers, thus, making it more reliable and flexible.
Testing Code Execution on the Client Side, Like the Web Browser
Puppeteer and Cypress have aspects of the client side where they allow testing code execution on the client-like web browser. In Puppeteer, manual operation can be done in the browser, and it is easy to create a testing environment for the test to run directly. You have the option to test the front-end function and UI testing with the use of Puppeteer. Further, Cypress aims to test like anything that could be run in the browser and executed to build a high user experience. It tests the flow of the application from start to end according to the view of the user. It also works equally well on older servers for the pages and applications.
Testing Behavior on the Server Side
The major difference between Puppeteer and Cypress is related to the allowance of the testing behavior of the server-side code, whereas Puppeteer does not have such aspects. However, Cypress has the ability to test the back-end behavior, say, for example, with the use of
cy.task() command. It gives the way to run the Node code. Through this, users can take actions crucial for the tests beyond the scope of Cypress.
Cypress comes with dashboards where you can be able to see the recorded tests and provide details on the events which happen during the execution. However, Puppeteer does not have such a dashboard, making it unable to record the test. Hence, transparency in the execution of the test is not maintained in Puppeteer.
Fixtures are the specific and fixed states of data that are test locals. This helps confirms a particular environment for a single test. Comparing the two, Cypress has the inbuilt fixtures abilities. With the use of the command
cy.fixture(filePath), you can easily load a fixed set of data that is located in a file. However, Puppeteer does not have any such fixtures.
Group fixtures let to define particular and fixed states of data for a group of tests which helps ensures the environment for a given group of tests. For this also, Puppeteer does not have any such fixtures. At the same time, Cypress has the ability to create group fixtures with the use of the
The blog has presented detailed comparisons of the Puppeteer and Cypress, which gives you enough information for you to decide which tools will be best according to your test requirement. LambdaTest is a cloud-based automation testing platform with an online Cypress automation tool that writes simple Cypress automation testing and sees its actions. Using LambdaTest, you can also test your Puppeteer test scripts online. Both Cypress and Puppeteer come with their own advantages and limitations. It would be best if you decided which suits best to your tests.
Published at DZone with permission of Nazneen Ahmad. See the original article here.
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