exceptionTransform.kt

fun <B, T : B, R : B> Flow<T>.exceptionTransform(errorHandler: suspend (exception: Exception) -> R): Flow<B> {
    return flow {
        var fromDownstream = false
        try {
            collect { value ->
                try {
                    emit(value)
                } catch (e: Exception) {
                    fromDownstream = true
                    throw e
                }
            }
        } catch (e: Exception) {
            if (fromDownstream) throw e
            emit(errorHandler(e))
        }
    }
}