Support ModuleKind.ESModule

[kpritam]

Latest Scala.js supports ModuleKind.ESModule, this option can not be used with ScalaJsBundler, we see this error:

java.lang.RuntimeException: scalaJSModuleKind must be set to ModuleKind.CommonJSModule in projects where ScalaJSBundler plugin is enabled

[julienrf]

Indeed, I think checking that scalaJSModuleKind has been set to something different than ModuleKind.NoModule should work. Ideally, we could also check that the webpack version used does support ES modules.

[vhiairrassary]

As a POC, when deactivating moduleKind check:

diff --git a/sbt-scalajs-bundler/src/main/scala/scalajsbundler/sbtplugin/ScalaJSBundlerPlugin.scala b/sbt-scalajs-bundler/src/main/scala/scalajsbundler/sbtplugin/ScalaJSBundlerPlugin.scala
index ace7f71..a8f6a93 100644
--- a/sbt-scalajs-bundler/src/main/scala/scalajsbundler/sbtplugin/ScalaJSBundlerPlugin.scala
+++ b/sbt-scalajs-bundler/src/main/scala/scalajsbundler/sbtplugin/ScalaJSBundlerPlugin.scala
@@ -569,7 +569,7 @@ object ScalaJSBundlerPlugin extends AutoPlugin {

     ensureModuleKindIsCommonJSModule := {
       if (scalaJSLinkerConfig.value.moduleKind == ModuleKind.CommonJSModule) true
-      else sys.error(s"scalaJSModuleKind must be set to ModuleKind.CommonJSModule in projects where ScalaJSBundler plugin is enabled")
+      else true
     },

     webpackBundlingMode := BundlingMode.Default,

with default webpackBundlingMode and

webpackCliVersion := "3.3.6"
version in webpack := "4.39.1"
version in startWebpackDevServer := "3.8.0"

scalaJSLinkerConfig ~= { _.withModuleKind(ModuleKind.ESModule) }

it just works with Scala.js 0.6.28, Chrome 76 by loading [name]-fastopt-bundle.js. Are there other areas to check before starting a complete pull request?

[julienrf]

Awesome, thanks for investigating!

Are there other areas to check

Maybe running tests, and running tests that use the DOM.

[KadekM]

Any news on this?

[exoego]

#336 seems inactive

[Lasering]

Is there anything I can do to help this move?

[julienrf]

Hello! Unfortunately, this project lacks maintainers. Something you could do to help this move would be to locally test the PR that has been open, to fix the git conflicts, and finally to notify the people watching the repository that the PR is ready to be merged.