José Matos
•07 May 2023
Debugging is widely regarded as one of the most frustrating aspects of programming. It can be a frustrating and time-consuming process, especially when faced with an elusive issue in your code that you just can't seem to put your finger on. When it comes to frontend development, debugging can be even more challenging. Dynamic changes to the website’s interface, inconsistent client environments, and a lack of visibility into the server-side of things can make it difficult to pinpoint the exact cause of a problem.
However, there are several debugging techniques that can help frontend developers quickly identify and solve issues, making the debugging process much easier. In this article, we will discuss some of the most effective techniques for debugging frontend code.
The first step in debugging a frontend issue is to use your browser's developer tools. These tools offer a set of features that allow developers to inspect and interact with HTML, CSS, JavaScript, and other code on a webpage. To access the developer tools, simply right-click anywhere on a webpage and select "Inspect" or press F12 on your keyboard.
The browser's developer tools provide several useful features, such as:
To diagnose a frontend issue using browser developer tools, observe the console and network logs to see if there are any errors or slow-loading elements. Additionally, use the "inspect element" feature to identify the exact element that is causing an issue and identify any problematic CSS properties that may be interfering with the design.
Aside from the developer tools that are built into your browser already, there are several other tools that can help you debug frontend code. These tools are dedicated to finding and identifying issues that more common tools may not be able to identify.
Some of the most popular debugging tools are:
Tools like Sentry and Chrome DevTools offer much-needed services to frontend developers by reducing the need for manual analysis of code, providing scopes for subscription tracing, and providing debugging tools that ease the pain of development.
Log files can be an effective way of identifying frontend issues. By logging data such as variable values or application-specific events, developers can track down where and when an issue occurs.
It's best practice to place log statements throughout your codebase to help identify the root cause of a frontend issue. In some cases, it's wise to add log statements to production code as well to identify runtime issues that may not appear in testing or staging environments.
Logging can be done via console statements or third-party logging libraries like Winston or Bunyan. Some libraries can even write to multiple output formats, including plain-text files, JSON, or syslog files.
Unit testing is the process of testing a small portion of code in isolation from the rest of the application/program. By testing these small portions of code, developers can identify issues at early stages before fully deploying an application or even running it through a staging environment.
Unit tests can be automated using testing libraries like Jest, Mocha or Jasmine. They aim to verify small chunks of code, ensuring they behave as intended before advancing to more comprehensive and full-stack testing.
Another powerful technique for debugging frontend applications is code review. Code review is a process where developers review each other's code, looking out for mistakes, and catching issues in the development process before they become problems.
The review process can involve a structured review process or a less-formal peer-review team. Both methods can help identify inconsistencies, missing validations and other issues that can surface later in the production stage.
Code reviewing is also an excellent way to improve the development conversation, sharing knowledge between developers, and making the development process more streamlined and consistent.
While unit testing is a good tester in isolation, the system isn't necessarily synced together. With automated testing, you can create targeted tests to evaluate end-to-end experiences and multi-function system performance.
Automated testing allows for tests to be easily reshaped after each test case or modification. This testing technique enables you to build upon slow UIs, broken servers, or analyze existing audits and correct any problems automatically.
Debugging is a vital part of the development process, but it doesn't have to be frustrating and time-consuming. By following some of these techniques for debugging frontend code, you can identify and solve issues with ease, and improve your overall development process.
Browser developer tools, dedicated debugging tools, logging, unit testing, code review and automated testing can all help make debugging a more manageable task. Remember to document and log whenever possible and ensure all parties are involved in the development conversation. Soon enough, finding that one elusive error making your static site not work as planned should no longer be feeling like finding a needle in a haystack.