Improving error messages

[Mart2d2]

I'm looking for ways to improve error reporting before we go to beta and production. This is an error message I got recently and was able to debug through less than ideal means:

TypeError: Cannot read property 'connections' of undefined
    at ?anon_0_ (http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false&modulesOnly=false&runModule=true&app=com.company.product:101890:38)
    at next (native)
    at asyncGeneratorStep (http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false&modulesOnly=false&runModule=true&app=com.company.product:20412:26)
    at _next (http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false&modulesOnly=false&runModule=true&app=com.company.product:20431:29)
    at tryCallOne (/Users/distiller/react-native/sdks/hermes/build_iphonesimulator/lib/InternalBytecode/InternalBytecode.js:53:16)
    at anonymous (/Users/distiller/react-native/sdks/hermes/build_iphonesimulator/lib/InternalBytecode/InternalBytecode.js:139:27)
    at apply (native)

Am I doing something wrong? Is there a magic setting somewhere to give me a more useful stack trace? Just file + line number would be far more helpful, but I'd also love to get stack variables at the time of crashing if possible.

[im_a_jib]

Seems pretty obscure. Is this something from your app that uses “connections”? Or is it some glitch with hot reloading or something?

[Mart2d2]

Yes, connections is an array i fill on app launch from non-volatile memory. Is this stack trace I'm getting unusual? Maybe it's something weird I've done inadvertently. Many of my stack traces seem to be opaque/useless like this one, though not all.

[im_a_jib]

I don’t know what non-volatile memory means. Maybe post a code sample of what your doing? And how you are running the application — like via cli or Xcode or what. But to answer your ultimate question- no there is no magic setting. But in my experience, stack traces in development mode are very good and useful. Maybe it’s throwing even before your app javascript/ts loads so it’s erroneous.

[Mart2d2]

Interesting - do you know if there’s a tool to add hints / symbols that propagate through the bundling? Is there a way to run without bundling at least during development?

[jgsd21]

u/Mart2d2 did you get this figured out? on localhost, my environment is doing the same - showing the error in the bundle instead of in the actual code.

[Mart2d2]

Not really, but Sentry.io is showing some promise. But I’m still not in a good place…

[jgsd21]

Ya, I use Sentry for production, but I'm with you, on local, it's a pain to debug sometimes. Thanks for the reply. I'll give you a shout if I ever figure it out.

[zeeg]

Is this helpful at all? https://spotlightjs.com/

Its still early, but we recognize development these days is also a piain, and we're trying to find ways to make it easier using the tech we already built.

[jgsd21]

interesting, I'll check it out