Is this the channel I ask for suggestions?

Hi not too sure if this is the channel i ask about mockk but I want to mock some behavior.

fun wait(){
    val timeout= TimeHelper.getNow() + timeoutInterval // <- part of class constructor
    if(processor.getLag() > 0){
        val currentTIme = TimeHelper.getNow() 

        if(currentTime >= timeout){ System.exit(42) }
        Thread.sleep(someTime)
    }
}

Is there a way for me to use mockk to either that

wait()

has executed for x amount of time with

verify(exactly = x) { someProcessor.wait() }

, or

Thread.sleep()

has been sleeping for x number of time? I have something like this in my test class

every { processor.getLag() } returns 1
every { TimeHelper.getNow() } returns 100

So after some number of executions

ever{ processor.getLag() } returns 0

to validate that it finishes

Is there any way that I can force compiler, IDE or any tool like detekt, klint to give error/warning when a method explicitly not defines the return type ?

fun exampleMethod() = "SomeString" // want to have warning/error
fun exampleMethod(): String = "SomeString" // this should pass

Hi, I'm a little confused about lambda expression. say we have a expression below

val return5 = {5}

I think it is equal to

fun return5(): Int {
  // note return here
  return 5
}

if so, please explain the code bellow:

fun test(fn: () -> Unit) {}

val foo =
    fun(name: String): String {
      return name
    }

test { foo } // why no error ?

I mean ,

test

accept a parameter , which is a function with the type

()->Unit

, but I think

test { foo }

is equals to

test(
      fun() {
        return foo
      })

Apparently it mismatch the type of parameter

fn

of the function

test

, the case above is

() -> String -> String

, but why no error here ? ``` ```

Hi all 🙂 How can i use

removePrefix()

if i have this string

Expiration Date: "2023-01-03 16:06:52 +0000 UTC"

and i want to get

"2023-01-03 16:06:52 +0000 UTC"

Are there any obvious resources for profiling concurrency in Kotlin? I ran the profiler in intellij idea but I had a hard time interpreting it.

I believe the lincheck library can help. https://github.com/Kotlin/kotlinx-lincheck

Are there any libraries like hljs? I'm trying to identify the programing language in an input

I’m trying the kotlin REPL in Intellij in my macbook pro for the first time, and running into an issue when trying to do something like.

min(10, 2)
error: unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
public fun <T : Comparable<TypeVariable(T)>> Array<out TypeVariable(T)>.min(): TypeVariable(T) defined in kotlin.collections
public fun Array<out Double>.min(): Double defined in kotlin.collections
public fun Array<out Float>.min(): Float defined in kotlin.collections
public fun ByteArray.min(): Byte defined in kotlin.collections

Hi everybody, are there any suggested materials for Kotlin algorithm for coding interview? Like how to do BFS, DFS in Kotlin? Thanks!

How would I write an extension function for a

T?

. In Haskell, I use the maybe function pretty frequently. The type is like

(default: U, f: (T) -> U, x: T?): U

Hi, folks! I have the following code snippet presented on the screenshot and two questions related to it: 1. the

srcDirs

property provides

Set<File!>

I further use with

.map(File::toPath)

– I assume it’s rather necessary to

.filterNotNull()

before, right? 2. As I have couple of chained operations – wouldn’t it be better to convert the initial set to sequence?

I posted this to #reflect but that channel doesn’t see any action. Perhaps someone can point me to resources to understand this probably very simple problem regarding reflection and copying data in a generic way from an instance of one class to another type. I am lost on receivers. grr. https://kotlinlang.slack.com/archives/C0AVAB92L/p1670535073508719

anyone know any good tutorials or walkthroughs of idiomatic Kotlin unit testing? coming from Junit/hamcrest/mockito experience in Java and it'd be nice to know how it 'should' be done. thanks

I have an issue with ktor in my project. Where is the best place to ask for troubleshooting advice?

Hi All, I'm going through Koan's Lazy Property example. The question is

Add a custom getter to make the val lazy really lazy. It should be initialized by invoking initializer() during the first access.
You can add any additional properties as you need.
Do not use delegated properties!

The answer code is

class LazyProperty(val initializer: () -> Int) {
    var value: Int? = null
    val lazy: Int
        get() {
            if (value == null) {
                value = initializer()
            }
            return value!!
        }
}

I tried the below and it also pass

class LazyProperty(val initializer: () -> Int) {
    val lazy by lazy {
        initializer()
    }
}

I'm not sure the intent of this tutorial introducing

lazy

, but not using

by lazy

. Is it to show us the

get()

instead? Thanks 🙏

Hi. A question about function references. Say I have two packages,

foo

and

bar

. in

bar.Baz.kt

I have this:

package bar

fun baz(i: Int) = i + 1

and in

foo.Foo.kt

this:

package foo

import bar.baz

fun xd(op: (Int) -> Int) {
    println("calling $op with param 4 and getting ${op(4)}")
}

fun main() {
    xd(::baz)
}

everything works great. now I want to get rid of

import bar.baz

. How do I do that?

xd(::bar.baz)

does not compile. What’s the syntax here?

Hello! Want to use value classes in multiplatform project in common source, but have faced with compiltion error. If not annotating value class with JvmInline got error for jvm target, else got error in js target for unresolved Jvminline annotation.

Does anyone know why the Kotlin compiler does not work with JDK 20, even with the Maven extension instead of Gradle? 🤔

If I want to have two loops to iterate an array of Int values (to compare them to each other), but I want the inner loop always start at outerIndex++, how would I do that? Currently I have

array.forEachIndexed { indexOuter, outer ->
        array.forEachIndexed { indexInnter, inner ->
            //I want this inner forEachIndexed to start at indexOuter++
        }
    }

Maybe a dumb question, but is there such a thing as a Map in Kotlin where you only need to specify the type of Key because you never actually plan on using the value? Or is there a different data structure that allows you to have constant time inserts and lookups? Example: I just want to know if I already "saw" a number in a list that I'm traversing, so I'm currently saving the fact that I saw it as a mapOf<Int, Boolean>, but the very existence of the Int would suffice and so the boolean seems redundant

Hi fellows Im using kgraphql and I have the following structure on my models:

data class A (
    val id: String,
    val b: B
)

enum class B{
    AA, BB, CC
}

Trying to run the app I have the following error:

Exception in thread "main" com.apurebase.kgraphql.schema.SchemaException: Cannot handle enum class class com.example.B as Object type

. Does someone know how to solve it?

Hello, I’m developing a kotlin library and using it on a java project but it is not including sources in my jar when I try to access it from intellij it says

compiled code

on the method implementations, any ideias?

👋 Hello, team!

When declaring an interface, I’ve kinda automatically defaulted to not exposing fields, but exposing functions directly, but not quite sure why. I’ve now had this one case where I had an interface expose a

StateFlow<Foo>

and had it behind a function

stateFlow(): StateFlow<Foo>

but the implementation simply had the private declaration and the overridden function was simply doing

return this.stateFlow

. So I wonder, is it weird for the interface to simply expose

val stateFlow: StateFlow<Foo>

instead? Are there any reasons why I would want to avoid that?

Dear colleagues, please allow me to introduce my Kotlin library for work with physical and other units: KotUniL. There are also other libraries that try to solve similar tasks. Unfortunately, they were all not good enough for my purposes and I developed my own. KotUniL is subject to Apache 2 license terms. It is available via MavenCentral. KotUniL is a library of functions and objects of Kotlin that meet the following requirements in total: 1. It covers all units of SI base units (see https://en.wikipedia.org/wiki/International_System_of_Units) like meter, second etc. as well as some other common units like currencies, percentages etc. 2. It allows various formulas to be written in Kotlin in a way maximally similar to the way formulas are written in physics and economics. 3. It allows analyzing dimensions of results of applications of complicated formulas. 4. It allows to detect most of the typical errors when working with SI units already at the compilation stage. Errors in incorrect use of physical units in complex formulas are detected in runtime. 5. It is pure library (no plug-in, no parser etc.), it has no dependencies MavenCentral: https://central.sonatype.dev/artifact/eu.sirotin.kotunil/kotunil/1.0.1/overview GitHub repository: https://github.com/vsirotin/si-units

I'm just getting started developing Kotlin MP. I'm on the 4th step of the getting started tutorial: https://kotlinlang.org/docs/multiplatform-mobile-upgrade-app.html Android app runs fine, but the iOS app crashes with:

/Users/abarsky/AndroidStudioProjects/KotlinMultiplatformSandbox/build/ios/Debug-iphonesimulator/iosApp.app
Uncaught Kotlin exception: kotlin.native.IncorrectDereferenceException: illegal attempt to access non-shared <object>@3d723a8 from other thread
    at 0   shared                              0x10375ea73        kfun:kotlin.Throwable#<init>(kotlin.String?){} + 95 
    at 1   shared                              0x103757f93        kfun:kotlin.Exception#<init>(kotlin.String?){} + 91 
    at 2   shared                              0x1037581c7        kfun:kotlin.RuntimeException#<init>(kotlin.String?){} + 91 
    at 3   shared                              0x10376a393        kfun:kotlin.native.IncorrectDereferenceException#<init>(kotlin.String){} + 91 
    at 4   shared                              0x10376ce9b        ThrowIllegalObjectSharingException + 415 
    at 5   shared                              0x103b0a02f        _ZN12_GLOBAL__N_128throwIllegalSharingExceptionEP9ObjHeader + 27 
    at 6   shared                              0x103b0b5f7        _ZN12_GLOBAL__N_136terminateWithIllegalSharingExceptionEP9ObjHeader + 11 
    at 7   shared                              0x103b0b7a7        _ZNK27BackRefFromAssociatedObject3refIL11ErrorPolicy3EEEP9ObjHeaderv + 231 
    at 8   shared                              0x103b0a837        _ZN12_GLOBAL__N_111toKotlinImpEP11objc_objectP13objc_selectorPP9ObjHeader + 51 
    at 9   shared                              0x103b011ab        Kotlin_Interop_refFromObjC + 111 
    at 10  shared                              0x1039e2cbb        _696f2e6b746f723a6b746f722d636c69656e742d64617277696e_knbridge101 + 207 
    at 11  shared                              0x103acb7cb        _696f2e6b746f723a6b746f722d636c69656e742d64617277696e_kncfun103 + 79 
    at 12  CFNetwork                           0x1049e37cf        /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/CFNetwork.framework/CFNetwork + 47055 
    at 13  Foundation                          0x105e4f8d7        __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 15 
    at 14  Foundation                          0x105e4f7cb        -[NSBlockOperation main] + 99 
    at 15  Foundation                          0x105e524f3        __NSOPERATION_IS_INVOKING_MAIN__ + 11

as the httpClient line is executed

@Throws(Exception::class)
    suspend fun greeting(): String {
        val rockets: List<RocketLaunch> =
            httpClient.get("<https://api.spacexdata.com/v4/launches>").body()

Here are my plugin versions

plugins {
    //trick: for the same plugin versions in all sub-modules
    id("com.android.application").version("7.3.1").apply(false)
    id("com.android.library").version("7.3.1").apply(false)
    kotlin("android").version("1.7.10").apply(false)
    kotlin("multiplatform").version("1.7.10").apply(false)
}

which were setup automatically for me when I made a new Kotlin Multiplatform App from within Android studio. https://kotlinlang.org/docs/multiplatform-mobile-create-first-app.html Running XCode 14.. Is there a complete project I can download to make sure it's not a mistake typing in the tutorial code?

Hi all not really sure if this is the right place to ask but I have some design questions/ best practice questions that I have. So essentially I was told that singleton / static variables should not be used for the business logic in my application. So essentially what I have is something like

class someClass(){

lateinit var one: String,
lateinit var two: String,
lateinit var three: customObject

}

So what I'm doing is throughout my code I'm updating these variables based on some conditions/criteria and I have another class that calls

someClass

and I will use getters to retrieve the

lateinit var

. Instead of these singleton variables, what should I be using? Should I be using a custom

data class

to store the state of the variables? The logic I have for these variables: one - Does the data already exist? yes -> one = existingData.one no -> one = generate some value and set two - Does the data already exist? yes -> two = existingData.two no -> two = generate some value and set && Are we done? yes -> no nothing. no -> generate some value and set three - Just update consistently to get the most recent Object to be passed into different class

Not sure if this is the right place to ask but I can't seem to fix this error

java.lang.RuntimeException: java.rmi.RemoteException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException:Cannot construct instance of `com.arcesium.recon.workflow.domain.BreakAnalysis` (no Creators, like default constructor, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (String)"{
  "@UUID" : "46435929-0621-40b9-b623-871dda721fdf",
  "breakAnalysisList" : [ {
    "@UUID" : "d339332a-babf-49b6-a17e-05584595810b",
    "id" : -1,
    "key" : {
      "@UUID" : "a96c68bb-4f80-49aa-b346-67a34b564123",
      "recUnitKey" : "1e364133-a8c1-590f-b13c-41e2f4e661bd",
      "componentId" : 67,
      "breakAnalysisId" : -1
    },
    "recGrainId" : 136,
    "openDate" : "2022-03-28",
    "closeDate" : "2022-04-08",
    "amount" : -0.58,
    "isChild" : false,
    "ttBegin" : "2022-12"[truncated 1484 chars]; line: 4, column: 5] (through reference chain: com.arcesium.recon.workflow.domain.BreakAnalysisRequest["breakAnalysisList"]->java.util.ArrayList[0]). For further assistance, please contact - <mailto:help@arcesium.com|help@arcesium.com> with tracking request id : 3e3453cc-0549-4117-81a7-c34530095500
	at com.arcesium.frames.client.RESTfulClient.handleThrowable(RESTfulClient.java:599)
	at com.arcesium.frames.client.RESTfulClient.executePost(RESTfulClient.java:479)
	at com.arcesium.frames.client.RESTfulClient.executePost(RESTfulClient.java:637)
	at com.arcesium.frames.service.util.JavaLightHelper.callRestMethod(JavaLightHelper.java:336)
	at com.arcesium.frames.client.api.proxy.ClientProxyUtils.executeApi(ClientProxyUtils.java:298)
	at com.arcesium.frames.client.api.proxy.RemoteProxy.invoke(RemoteProxy.java:304)
	at com.sun.proxy.$Proxy266.createBreakAnalysis(Unknown Source)
	at deshaw.munshi.reconcilers.service.util.BreakSyncUtil.createBreakSync(BreakSyncUtil.kt:181)
	at deshaw.munshi.reconcilers.service.util.BreakSyncUtil$$FastClassBySpringCGLIB$$b6334f06.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
	at org.springframework.aop.interceptor.AsyncExecutionInterceptor.lambda$invoke$0(AsyncExecutionInterceptor.java:115)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.rmi.RemoteException: com.fasterxml.jackson.databind.exc.InvalidDefinitionException:Cannot construct instance of `com.arcesium.recon.workflow.domain.BreakAnalysis` (no Creators, like default constructor, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (String)"{
  "@UUID" : "46435929-0621-40b9-b623-871dda721fdf",
  "breakAnalysisList" : [ {
    "@UUID" : "d339332a-babf-49b6-a17e-05584595810b",
    "id" : -1,
    "key" : {
      "@UUID" : "a96c68bb-4f80-49aa-b346-67a34b564123",
      "recUnitKey" : "1e364133-a8c1-590f-b13c-41e2f4e661bd",
      "componentId" : 67,
      "breakAnalysisId" : -1
    },
    "recGrainId" : 136,
    "openDate" : "2022-03-28",
    "closeDate" : "2022-04-08",
    "amount" : -0.58,
    "isChild" : false,
    "ttBegin" : "2022-12"[truncated 1484 chars]; line: 4, column: 5] (through reference chain: com.arcesium.recon.workflow.domain.BreakAnalysisRequest["breakAnalysisList"]->java.util.ArrayList[0]).

Adding a default constructor doesn't help , does anyone have any idea how to resolve this ? This is how my class looks like

data class BreakAnalysis(
	var id: Long,
	val key: BreakAnalysisKey,
	val recGrainId: Int,
	val openDate: LocalDate,
	val closeDate: LocalDate,
	val amount: BigDecimal,
	val isChild: Boolean?,
	var associatedBreakIds: List<Long>?,
	val ttBegin: LocalDateTime,
	val ttEnd: LocalDateTime,
	val systemInsertionRuleId: Int?,
	val groupId: Long,
	val partitionDate: LocalDate,
	val associatedBreakMetaData: Map<String, Any>?,
	val breakMetadata: Map<String, Any>?,
	val recTypeFamilyId: Int,
	val reasonId: Int,
	val ageStartDate: LocalDate,
	val cpidDetails: Map<String, Any?>?,
	val expressionEvaluationDetails: Map<String, Any?>?,
	val grainMap: Map<String, Any?>?,
	val clientUserName: String?,
	val createdBy: String?,
	val updatedBy: String?,
	val previousModificationBy: String?,
	val isWriteOff: Boolean?,
	val comments: String?,
	val clientComments: String?,
	val wireId: Int?,
	val userTranId: String?,
	val settlementPrice: BigDecimal?,
	val side1Quantity: BigDecimal?,
	val side2Quantity: BigDecimal?,
	val side1Amount: BigDecimal?,
	val side2Amount: BigDecimal?,
	val tick: BigDecimal?,
	val side1TradePrice: BigDecimal?,
	val side2TradePrice: BigDecimal?,
	val adminInvestmentCode: String?,
	val investmentDescription: String?,
	val recStatusId: Int,
	val breakAnalysisWorkflow: BreakAnalysisWorkflow?,
	val attachments: List<Attachment>,
	val workUnitId: Int,
	val workUnitTypeId: Int,
	val contributedToComponentIds: Set<Int>?,
	val reconManifestationId: Long?,
	val uiWorkUnitId: Int?
) {
	constructor(): this(-1, BreakAnalysisKey(),-1,LocalDate.now(),LocalDate.now(),
			BigDecimal.valueOf(0),null,null,LocalDateTime.now(),
			LocalDateTime.now(),null,-1,LocalDate.now(),null,
			null,1,-1,LocalDate.now(),null,null,
			null,null,null,null,null,null,
			null,null,null,null,null,null,
			null,null,null,null,null,null,
			null,null,-1, null, emptyList(),
			-1,-1,null,null,null
	)
}