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Vivek Kumar

Debugging React CSS Transitions

Vivek Kumar

  • Sep 16, 2019
  • 6 Min read
  • Sep 16, 2019
  • 6 Min read
Web Development


When we talk about the rendering of CSS transitions in React, then it may seem obvious that most of the time, we avail stable and reliable outputs in one attempt. This is because the React framework is applied when we have to get swift, yet professional, results in CSS language.

For a transition that has been crafted professionally, the margin of goofing up things is negligible. For the exact same reason, it is essential to identify the potential bugs are that can actually hamper your transitional framework in advance and take pre-emptive measures to guard against the probable loophole(s). The process of debugging demands strong countermeasures because, apart from a transition breakdown, the bug can actually compromise the security of the portal and easily invite hacking threats.

The process of debugging React CSS transitions for seamless rendering enables you to create a standard checklist and ensures that all the potential checkpoints for the bugs are neutralized. By the time you read the final line of this guide, you will be familiar with the components that are prone to bug attacks and how can you counter these threats in the process of debugging. Besides, we are going to shed some light on some of the most notable bug fixes that are prevalent and why they are popular among the animators.

So, let us begin with how to safeguard your React CSS transitions for a prolonged period of time.

A Dummy Bug Demo

Just have a look at a situation where a bug warning has been displayed from React in the console:

Warning: transition(): tried to perform an animation without main.js55681 an animated or transitioned event after timeout (5000ms). You should either disable this transition in JS or add a CSS animation/transition.

This is one of the standard bug warnings that you normally encounter and, under one such circumstance, it is essential that you round up all prime usual suspects that might be affected with a bug infestation to be checked.

  • All child components related to <ReactCSSTransitionGroup> component with predefined key attributes.
  • All <ReactCSSTransitionGroup> components having a predefined set of transitionName properties.
  • All types of transitionNames that have an applicable .example-enter-active, .example-enter, .example-leave, or .example-leave-active set of classes combining animations with a duration below 5000ms.
  • All kinds of ReactCSSTransitionGroup components mounted prior to the modification of their child components.

Now, it is not easy to find the prime culprit when there are many suspicious elements right in front of you. It is essential to trace which document object model (DOM) element is actually triggering the warning.

Working on the Solution

First and foremost, please make sure that you are modifying the child components prior to the mounting of the elements in the ReactCSSTransitionGroup. Thereafter, work on the functioning of the browser in which the bug infection has been detected. In order to detect the nature of the transitions, it is recommended to mention timeout manually. The CSSTransitionGroup is simply required to take timeouts like TimeoutTransitionGroup. In order to enhance reliability, CSSTransitionGroup does not require listening to the transition events. In order to mention the transition time period manually, it is suggested to go with the props like transitionEnterTimeout={500}.

Here's a list of few important bug fixes which may be helpful while performing debugging in React 0.14:

  • The click events are functioned by the React Document Object Model (DOM) in the mobile browsers in a trustworthy manner, especially in Mobile safari.

  • In maximum possible cases, the Scalable Vector Graphics (SVG) elements are formed with the correct namespace.

  • It is now feasible to render <option> elements by the React Document Object Model (DOM) with several text child properties and then render <select> components on a server by choosing the correct option.

  • The application of non-lowercase type HTML tag names carried in the React Document Object Model (DOM) doesn't cause any problem. For instance, React.createElement('DIV') is not going to generate complications anymore. Yes, of course, in order to ensure consistency with the JSX tag name convention, we linger with the suggestion of lowercase application. For those who don’t know, the lowercase names indicate built-in components and, on the other hand, capitalized names are basically designated to the custom components.

  • The React Document Object Model can easily comprehend the fact that CSS properties are basically unitless and do not affix px with respect to the values of animationIterationCount, flexOrder, boxOrdinalGroup, stopOpacity and tabSize.

  • The add-ons while utilizing the test Simulate.mouseEnter, Simulate.mouseLeave, and utils are now functional.

  • The add-ons: The good news is that ReactTransitionGroup can now precisely handle several nodes being removed in a simultaneous manner.


While understanding the concept of debugging the React CSS transition, we dealt with numerous components responsible for making our transition a better experience each and every time. We tried to learn how these components get affected by bugs and which situations need your urgent attention. In this guide, I have also tried to emphasize certain techniques that can help you prevent the transition bug and, at the end, we went through a list of popular bug fixes.

It is anticipated that the information provided in this guide is really going to make a difference in your next attempt to debug a React CSS transition.


You can further refer the following resources which are also used as references for this guide: