Could not call Config.resolve in Scalajs

[andares]

[info] Done compiling.
[info] Fast optimizing /bhc/target/scala-2.12/bhc-fastopt.js
[error] Referring to non-existent class java.util.IdentityHashMap

It looks use typeconfig lib to resolve hocon config. There is not IdentityHashMap exists in scala lib, can I find other way to resolve it?

[ekrich]

@andares This is a bug, thanks for reporting. This class is missing in the Scala.js Java library and because all the tests are not run with Scala.js - this bug was not found.

Right now we cannot share tests because we don't have a shared test framework for all three platforms but I would like to find or have a test for this so if you could supply the code you used to create the error it would be helpful.

[andares]

I'm glad to be able to support.

here is my code, I have to say I'm a beginner in scala 😹

package example

import org.ekrich.config._
import scala.io.Source

object Test extends App {
  def parseFile() = {
    // That's not work, need `java.io.File`
    val config = ConfigFactory.parseString("main.conf")
    println(config.resolve)
    // println(config)
  }

  def parseString() = {
    val content = """
_pattern.default.main = "../default/main.conf"

core = {
  version: 0.1
  extends: [
    ${_pattern.default.main}
  ]
}
"""
    val config = ConfigFactory.parseString(content)
    println(config.resolve) // That's crash
    // println(config) // That's ok
  }

  // --> run test
  // parseFile
  parseString
}

here is build.sbt content:

import Dependencies._

ThisBuild / scalaVersion     := "2.12.8"
ThisBuild / version          := "0.1.0-SNAPSHOT"
ThisBuild / organization     := "com.example"
ThisBuild / organizationName := "example"

lazy val root = (project in file("."))
  .settings(
    name := "bhc",
    libraryDependencies += scalaTest % Test,
  )

// See https://www.scala-sbt.org/1.x/docs/Using-Sonatype.html for instructions on how to publish to Sonatype.

// sconfig
libraryDependencies += "org.ekrich" %%% "sconfig" % "0.9.+"

// scalajs
enablePlugins(ScalaJSPlugin)
scalaJSUseMainModuleInitializer := true

Talk a little more, at the beginning I thought I could get the best support for hocon in scala. but I found Scala relies heavily on java libraries on the jvm platform. I think scalajs is hard to deal with, may be use js lib by interop is better way 🤣

[ekrich]

Scala.js doesn't have any support for java.io.File so we don't expect that to work but I think you should be able to call resolve but right now Scala.js doesn't have support for IdentityHashMap. I may be able to add it locally at first until we can get it added to Scala.js.

[andares]

That's ok, thank you for the reply 👍

[ekrich]

Test with working example - https://github.com/ekrich/sconfig/blob/master/sconfig/native/src/test/scala/ConfigFactoryTests.scala#L43-L62

[andares]

That's great! I have try it again.

[ekrich]

@andares Sorry, I didn't mean to mislead you. I am still working on the Scala.js support for this feature. I just made a test case that works on Scala Native that I can use to test when finishing development on Scala.js. I will close this ticket out once completed and then will need to make a new release for the Scala.js support of this feature.

[andares]

I see, I have parse hocon file with npm lib now, never mind 👌

[ekrich]

I'm sorry you had to resort to that but thanks for reporting and your interest. I have been working on this issue but it requires adding java.util.IdentityHashMap to Scala.js, first locally and then via a PR to Scala.js. It may be working but I just found out how to do resolve myself. I am not a config expert but have spent a bunch of time porting this library.

If you are using Scala.js you can get help here - https://gitter.im/scala-js/scala-js There is another HOCON lib for Scala.js that is very lightweight. https://github.com/akka-js/shocon I hope you keep using Scala.js.

If you would like to discuss further you can find me here as well. https://gitter.im/ekrich/sconfig

[andares]

Thank you for your help indeed. I'll keep trying Scala.js in my project. As compile to js language, use npm lib to resolve problem is also possible 😄 You can close the issue when the work is over.

[ekrich]

Fixed by #57