When things fail.
WHAT WILL FAIL
Network requests External services Component rendering Anything depending on browser capabilities
WHAT AN ERROR BOUNDARY DOES
Catches a rendering error and displays a fallback, rather than the whole application disappearing.
WHERE TO PLACE THEM
Around sections that can fail independently.
WHY NOT ONLY AT THE TOP
A single boundary means any failure removes everything.
WHAT TO SHOW THE USER
What happened, in plain language What they can do A way to retry
WHAT NOT TO SHOW
Technical detail A blank screen Nothing at all
WHAT TO DO ABOUT REQUEST FAILURES
Distinguish between failures: not found, not permitted, server error, network unavailable.
WHY
Each warrants a different message.
WHAT TO HANDLE SPECIFICALLY
Being offline, which is common on mobile connections.
WHAT TO REPORT
Errors, to a collection service.
WHY
Otherwise you only learn about failures users bother to report, which is very few.
WHAT TO INCLUDE IN REPORTS
Enough context to reproduce, without personal data.
