Hey everyone. I have a function that looks like t...

# announcements

[mng]

Hey everyone. I have a function that looks like this:

fun getMyResult(): Result<TheThing>{
    var myResult = Result.success(TheThing())
    return myRresult.mapCatching {
           throw IllegalArgumentException("")
    }
}

My expectation here is that the getMyResult() function will return a Failure Result that wraps the IllegalArgumentException. However, what is happening is that my application just crashes. Am I misunderstanding how mapCatching works?

[Matteo Mirk]

In theory yes, but how is it crashing? With that IllegalArgumentException or other?

[Daniele Andreoli]

maybe could be the typo on return myRresult.. ? 🤔

[mng]

@Daniele Andreoli i simplified my function here and typed it in so no typo in the actual method 🙂

[mng]

@Matteo Mirk yeah the crash is happening at the IllegalArgumentException

[elizarov]

Do you have a self-contained reproducer? Does not repeat for me: https://pl.kotl.in/TkAFX7Drc

[mng]

@elizarov I tried to reproduce in the playground you posted but can’t seem to repro it. https://pl.kotl.in/atQcSt6Or
The more accurate representation, as shown in my link, is that it’s a suspend function that contains the mapCatching though i’m not sure if that should change anything

[mng]

image.png

[mng]

This is the exact stack trace in my project that I get, with the line number pointing directly at the mapCatching

[mng]

I found the issue to my problem and it’s pretty silly.

it was crashing because I was calling getOrThrow at one of the call sites for this particular function 🤦‍♂️ . What’s bizarre though is that the logs point me to mapCatching instead of the getOrThrow location