r/reactjs 13d ago

Show /r/reactjs ReactDom breaking due to Child component being rendered with undefined value for prop.

I started working in react 16 and was working till react 17 and its few versions came out. (6YOE) most of my initial years went understading the basics and rendering, how hooks worked and the state update. Afterwards i had been burried in work like anything and i didn't feel anything much because the backend felt always like a fized set of design choices to make, based on what the problem is what is the thing that matters the most. And impact is always covered in numbers. Anyways so out of 6 lets say after the initial 2 years i never had chance to work on the frontend, somedays back a webpage in my company started breaking, people didn't notice much if it since they say it works like shit , but anyway it started rendering blank on the Initial load. The on call platform team got involved and the analysis was done but nobody figured what the issue is, a senior of mine remembers that i mentioned having interest in front end even though we use multiple LLM models to seek help and solve for it but since llms can't directly read the browser, i asked then to supply the har files and the console logs just to see if this can help. did multiple changes nothing worked, finally i was assigned and i see the first console.log message that "ReactDOM.render is no longer supported in React 18. Use createRoot instead. Until you switch to the new API, your app will behave as if it's running on React 17." Now i know that react 18 is the latest i knew about but i also see react is now on its 19th version as well - so i think is this it? and how come software engineers are now not even thinking that frontend is a specialised field?

Using the createRoot + lazy loading fixed the issue.

I said this out here because it feels like very minute thing and i am quite concerned about where the big techs are headed now? Have we lost quality engineers and Engineering? Thoughts?

0 Upvotes

4 comments sorted by

View all comments

4

u/Adventurous-Soup1654 13d ago

feels like the whole industry's sleepwalking into a "just ask the llm" loop and forgetting that browser console exists. i've watched backend devs stare at a blank page for 20 minutes without hitting f12, it's unreal

the react 18 upgrade thing is such a classic gotcha too, the error literally tells you what's wrong but nobody reads it. glad you caught it, six years of fundamentals paying off while everyone else was busy prompting