Book Image

UI Testing with Puppeteer

By : Dario Kondratiuk
Book Image

UI Testing with Puppeteer

By: Dario Kondratiuk

Overview of this book

Puppeteer is an open source web automation library created by Google to perform tasks such as end-to-end testing, performance monitoring, and task automation with ease. Using real-world use cases, this book will take you on a pragmatic journey, helping you to learn Puppeteer and implement best practices to take your automation code to the next level! Starting with an introduction to headless browsers, this book will take you through the foundations of browser automation, showing you how far you can get using Puppeteer to automate Google Chrome and Mozilla Firefox. You’ll then learn the basics of end-to-end testing and understand how to create reliable tests. You’ll also get to grips with finding elements using CSS selectors and XPath expressions. As you progress through the chapters, the focus shifts to more advanced browser automation topics such as executing JavaScript code inside the browser. You’ll learn various use cases of Puppeteer, such as mobile devices or network speed testing, gauging your site’s performance, and using Puppeteer as a web scraping tool. By the end of this UI testing book, you’ll have learned how to make the most of Puppeteer’s API and be able to apply it in your real-world projects.
Table of Contents (12 chapters)

Creating HTML content

In this section, we will see a few simple features but pretty useful ones. You will be able to follow the code from this section in the demohtml.js file. Most of the time, you navigate pages using the HTTP protocol as we did with Wikipedia. If you open the mediaprint.html file, you navigated to that page using the pseudo protocol "file." Although it's not a real protocol, you should know that with Puppeteer, you can also navigate local files using a URL such as file:///some/folder/of/my/computer/mediaprint.html.

So, if you want to generate a social image, like the HolyJS conference one we saw in the first section, you could create a page on your website, navigate to that page using Puppeteer, take a screenshot, and use that image in your social post.

You could also have that file stored locally and navigate that file using the file:// protocol.

What I want to show you in this section is that you don't necessarily need to have a file...