I think you didn’t get the real Java’s motto
“Write once, test everywhere”
This is just my opinion so please don’t be offended. I hope the idea of using front-end and back-end with a single language DO NOT become immensely popular. It is popular but I don’t want it to be the standard. Imagine a world where 99.99% of the web application is written using JavaScript. As a developer, we’re known to get ‘bored’ very quickly. I don’t want to write only JS for next 30 years of my career. Also, not everyone likes JS. I consider JS as a ‘double edged’ sword…since there are so many ways to do dumb things compared to other strongly typed languages. I prefer a language that is a ‘single edged sword’. It’s not as efficient as ‘double edged sword’ but I just feel safer. By all means, I’m not saying Node.JS is horrible or not but I feel a developer should not be afraid to learn a new programming language and not be stuck on ‘Js is the best and this is the only thing I’ll ever use’ mentality.
Also, the code sharing for front-end and back-end have horrible use cases.
Purpose of
Front-end: Provide UI and provide visualization from back-end data
Back-end: Process business logics that usually deals with integrating with multiple datasources (database for ex.)
There is very little share code in between because they serve different purposes. They commonly use example of ‘Form field validations’ that is used on JS side and Server side… Is it that much redundant code to check for field that has a value or not or doing date format check? So at the end, I’m guessing less then 5% of the code is being shared between front-end and back-end. I can be wrong and I like to be proved wrong. Using universal language to share 5% of the code doesn’t make any sense to me.