FlowConverterFacotry: java.util.NoSuchElementException: List is empty.

[ahmadmssm]

Ktorfit version

1.11.1

What happened and how can we reproduce this issue?

I didn't find the FlowConverterFactory in the last version as I previously reported, so I copied it from the Repo but when trying to parse any response it falls at this line
val response = getResponse()
with this error
java.util.NoSuchElementException: List is empty.

What did you expect to happen?

The parsing to success as in the previous versions.

Is there anything else we need to know about?

No response

[ahmadmssm]

I rolled back to a previous build and both bugs were not reproducible.

[ahmadmssm]

The issue is here

  if (requestType.typeInfo.type == HttpResponse::class)
                            emit(getResponse())

if I add more than one response converter, it will jump automatically when I call getResponse() to the other response converter, if there is only one converter, then it will work as expected.

[niyajali]

Hi, I'm getting the same error on the release build whereas on debug build it's works fine.

ktorVersion = "3.0.0"
ktorfit = "2.1.0"
ktorfitKsp = "2.1.0-1.0.26"

Caused by: java.util.NoSuchElementException: List is empty.                                                                                 
	at kotlin.collections.CollectionsKt___CollectionsKt.first(_Collections.kt:221)                                                          
	at org.mifospay.core.network.utils.FlowConverterFactory$responseConverter$1.convert(FlowConverterFactory.kt:32)                         
	at org.mifospay.core.network.utils.FlowConverterFactory$responseConverter$1.convert(FlowConverterFactory.kt:30)                         
	at de.jensklingenberg.ktorfit.internal.KtorfitConverterHelper.request(KtorfitConverterHelper.kt:33)                                     
	at org.mifospay.core.network.services._ClientServiceImpl.getAccounts(_ClientServiceImpl.kt:148)                                         
	at org.mifospay.core.data.repositoryImp.SelfServiceRepositoryImpl.getActiveAccountsWithTransactions(SelfServiceRepositoryImpl.kt:139)   
	at org.mifospay.feature.home.HomeViewModel.<init>(HomeViewModel.kt:47)                                                                  
	at org.mifospay.feature.home.di.HomeModuleKt$HomeModule$lambda$0$$inlined$viewModelOf$default$1.invoke(ViewModelOf.kt:17)               
	at org.mifospay.feature.home.di.HomeModuleKt$HomeModule$lambda$0$$inlined$viewModelOf$default$1.invoke(ViewModelOf.kt:59) (Ask Gemini)  
	at org.koin.core.instance.InstanceFactory.create(InstanceFactory.kt:50)                                                                 

[ahmadmssm]

@niyajali
Try using the following combination together
ktorVersion = "3.0.0"
ktorfit = "2.1.0"
ktorfitKsp = "2.0.21-1.0.25"

[Foso]

@niyajali Could be an issue with R8. What does your ConverterFactory look like?

[niyajali]

I'm using Ktorfit FlowConverterFactory

[Foso]

@niyajali So you are using exactly the same code as in here in your code? https://github.com/Foso/Ktorfit/blob/master/ktorfit-converters/flow/src/commonMain/kotlin/de/jensklingenberg/ktorfit/converter/FlowConverterFactory.kt

I'm asking because based on the package name "org.mifospay.core.network.utils.FlowConverterFactory" you are using your own class and i have other way of knowing what the code in there looks like

[niyajali]

@Foso Yes I've copied exact same code, and also tried with ktorfit-flow-converter library and getting the same error on release build

[niyajali]

package org.mifospay.core.network.utils

import de.jensklingenberg.ktorfit.Ktorfit
import de.jensklingenberg.ktorfit.converter.Converter
import de.jensklingenberg.ktorfit.converter.KtorfitResult
import de.jensklingenberg.ktorfit.converter.TypeData
import io.ktor.client.call.body
import io.ktor.client.statement.HttpResponse
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.flow

/**
 * Factory that enables the use of Flow<T> as return type
 */
public class FlowConverterFactory : Converter.Factory {
    override fun responseConverter(
        typeData: TypeData,
        ktorfit: Ktorfit,
    ): Converter.ResponseConverter<HttpResponse, *>? {
        if (typeData.typeInfo.type == Flow::class) {
            return object : Converter.ResponseConverter<HttpResponse, Flow<Any?>> {
                override fun convert(getResponse: suspend () -> HttpResponse): Flow<Any?> {
// Getting error on below line, somehow typeArgs is empty after applying progurd, so when we calling first() resulting NoSuchElementException
                    val requestType = typeData.typeArgs.first() 
                    return flow {
                        val response = getResponse()
                        if (requestType.typeInfo.type == HttpResponse::class) {
                            emit(response)
                        } else {
                            val convertedBody =
                                ktorfit.nextSuspendResponseConverter(
                                    this@FlowConverterFactory,
                                    typeData.typeArgs.first(),
                                )?.convert(KtorfitResult.Success(response))
                                    ?: response.body(typeData.typeArgs.first().typeInfo)
                            emit(convertedBody)
                        }
                    }
                }
            }
        }
        return null
    }
}