Learning about the Internals of Node.js

For years, being a frontend developer meant writing a bit of HTML and putting some styling with CSS on it. However, since the last decade, this job description barely holds true. In contrast, the majority of frontend work is now done using JavaScript.

Initially used to make cosmetic enhancements to websites (such as the toggling of elements) possible, frontend development is now the glue of the web. Websites are no longer just written in HTML and CSS. Instead, in many cases, web pages are programmed with JavaScript using modern techniques such as dependency management and bundling of resources. The Node.js framework provides an ideal foundation for this movement. It enables developers to use JavaScript not only inside websites running in a browser but also within the tooling to write web pages – outside of a browser.

When Node.js was released in May 2009, it did not seem like a big deal. JavaScript was working on the server too. However, the cross-platform nature of Node.js and the size of the JavaScript community provided the basis for one of the greatest disruptions in the history of computing. People started adopting the framework so quickly that many existing frameworks either disappeared or had to be reworked to stay attractive to developers. Soon, JavaScript was used in the browser and on the server and was also part of every frontend developer’s toolbox.

With the rise of new development frameworks such as Angular or React, the need for attractive frontend tooling became apparent. The new frameworks always relied on some build steps – otherwise, websites and applications using these frameworks would have been far too inconvenient to write for developers. Since the vast Node.js ecosystem seemed to have figured out a suitable approach for reusability, these new frameworks adopted it and made it an integral part of their development story. This way, using Node.js became the de facto standard for frontend projects of any kind.

Today, it is pretty much impossible to start a frontend development project without having Node.js installed. In this book, we’ll take the journey of learning about Node.js from the inside out together. We will not be focusing on writing server applications or walking over the integrated functionality of Node.js. Instead, we’ll look at how we – as frontend developers – can leverage the best that Node.js brings to the table.

In this first chapter, we discuss the internals of Node.js. This will help you understand how Node.js works and how you can actually use it. After this chapter, you will be able to run and debug simple scripts using the Node.js command-line application.

We will cover the following key topics in this chapter:

• Looking at the Node.js architecture in detail
• Understanding the event loop
• Using Node.js from the command line
• CommonJS