Hi there, have a QQ, let me know if this is not th...

# announcements

[Joao Birk]

Hi there, have a QQ, let me know if this is not the right channel.

By calling <string>.startsWith("$$"), I see some IllegalArgumentException reports coming from that:
Caused by: java.lang.IllegalArgumentException:
at kotlin.text.StringsKt__StringsJVMKt.b (StringsKt__StringsJVMKt.java)
at kotlin.text.StringsKt__StringsJVMKt.startsWith$default (StringsKt__StringsJVMKt.java:195)

I checked the code and dont see anything related and why this might be throwing such exception.

Unfortunately I dont have a sample string that is causing the issue.

[Michał Jurczyk]

Are you calling that in Kotlin code or Java code? 🤔

[Joao Birk]

calling from kotlin code

[Michał Jurczyk]

And I assume what you posted is the top of the stack trace and there is no additional comment? 🤔 Like "Desired length -9000 is less than zero."?

[Joao Birk]

That is correct

[Joao Birk]

below that is just the class that actually called this and thats it.

[karelpeeters]

Well what's at line StringsJVMKt.java:195?

[karelpeeters]

Also is that the full stacktrace, not a part of it in the middle?

[Joao Birk]

correct

[Joao Birk]

StringsJVMKt.java:195 ->

@Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
public actual fun String.startsWith(prefix: String, ignoreCase: Boolean = false): Boolean {
if (!ignoreCase)
return (this as java.lang.String).startsWith(prefix)
else
return regionMatches(0, prefix, 0, prefix.length, ignoreCase)
}

[karelpeeters]

I can't find anything, the only place String throws IllegalArgumentException is in the constructor when it encounters an invalid codepoints, and you're not constructing a string here.

[Joao Birk]

exactly, i bumped into that method too

[karelpeeters]

A test string would be great simple smile

[ilya.gorbunov]

IllegalArgumentException can be thrown as a result of a failed null check of the incoming parameters: the receiver string or the prefix string.

[Joao Birk]

fun unsubscribe(symbols: List<String>) {
symbols.filterNot { it.startsWith("$$") }.forEach {

[Joao Birk]

so you saying that an element in that list is String??

[Joao Birk]

if thats the case the call to unsubscribe would fail when passing the list param no? with the IllegalArgumentException

[karelpeeters]

No you can't really typecheck the contents of a list at runtime, generics are erased.

[Joao Birk]

hmm, true

[Joao Birk]

This was very helpful, thank you all!