JavaScript is known as a potentially strong programming language for creating web pages and applications that are interactive enough to keep users hooked. Various programs are being used to make amazing designs. JavaScript is used all over the world by developers and programmers even beginners are learning it to create web pages. Every website has elements that are only created by JavaScript. Programming becomes easier with the help of libraries and frameworks. Angular is a JavaScript structural framework used for creating dynamic web applications. It is an open-source framework for creating front-end apps. On the other hand, Karma is a JavaScript open-source test runner designed by the Angular JS team. It is used to test framework features with tools that existed.
You can simply add it to your project and test using CLI. It can be used to run tests on phones, tablets, and browsers. When working with it, you can encounter the error “DeprecationWarning: Pattern %d{DATE} is deprecated due to the confusion it causes when used. Please use %d{DATETIME} instead”. Check out how the error occurs
How the error pops up
When you try to run the unit test using Angular, you end up with the following error warning
(node:14940) [log4js-node-DEP0004] DeprecationWarning: Pattern %d{DATE} is deprecated due to the confusion it causes when used. Please use %d{DATETIME} instead.Cause of the error
You get the error warning because of Karma, which is a test runner. To test your project, Karma needs to be informed about it in the correct way to execute the test, which can be done using your configuration file. In order to create an initial configuration file, you need to use the ‘Karma init’ command. Karma configuration file can be created by JavaScript, which you can load just like the module of node.js.
The Solution to Fix “DeprecationWarning: Pattern %d{DATE} is deprecated due to the confusion it causes when used. Please use %d{DATETIME} instead”
To sort out the error, we have a solid solution that can be really helpful.
Solution – Update Karma
As this error is associated with Karma, it is removed when handling Karma the right way. The quickest and simplest solution is to update karma. The version that works fine is ^6.3.12. So, update the version to ^6.3.12 to remove the error warning.
Conclusion
In this post, we discussed Karma and the solution to fix the error “DeprecationWarning: Pattern %d{DATE} is deprecated due to the confusion it causes when used. Please use %d{DATETIME} instead”. You just need to update the version to resolve the error.
I hope you find it helpful! I wish you luck!