如何在ScalaJS build.sbt中设置mainClass？

Question

如何在ScalaJS build.sbt中设置mainClass？

目前我在build.sbt中设置了这样的主类(参见最后一行):

enablePlugins(ScalaJSPlugin)

name := "ScalaJS-Exp"

scalaVersion := "2.11.7"

libraryDependencies += "org.scala-js" %%% "scalajs-dom" % "0.8.1" 
libraryDependencies += "be.doeraene" %%% "scalajs-jquery" % "0.8.0" 

jsDependencies += RuntimeDOM

skip in packageJSDependencies := false

//scalaJSStage in Global := FastOptStage

// uTest settings
libraryDependencies ++= Seq(
    "com.lihaoyi" %%% "utest" % "0.3.1" % "test",
    "com.lihaoyi" %%% "scalatags" % "0.5.4",
    // Javascript libs
    "org.webjars" % "jquery" % "1.10.2",
    "org.webjars" % "jquery-ui" % "1.11.4"
)

jsDependencies ++= Seq(
    "org.webjars" % "jquery" % "1.10.2" / "jquery.js",
    "org.webjars" % "jquery-ui" % "1.11.4" / "jquery-ui.js" dependsOn "jquery.js"
)

testFrameworks += new TestFramework("utest.runner.Framework")

persistLauncher in Compile := true
persistLauncher in Test := false

mainClass := Some("htmlExp.HtmlExpApp")

当我跑步时,我得到:

[warn] Multiple main classes detected.  Run 'show discoveredMainClasses' to see the list
[trace] Stack trace suppressed: run last compile:packageScalaJSLauncher for the full output.
[error] (compile:packageScalaJSLauncher) Cannot write launcher file, since there is no or multiple mainClasses
[error] Total time: 1 s, completed Jan 23, 2016 4:36:02 PM
> show discoveredMainClasses
[info] List(htmlExp.HtmlExpApp, tutorial.webapp.MyApp)
[success] Total time: 0 s, completed Jan 23, 2016 4:36:13 PM
>

它没有效果如果我从build.sbt中删除mainClass设置.错误消息与mainClass设置相同或没有它.

在sbt提示符下,当我尝试runMain htmlExp.HtmlExpApp时,它工作并运行相关的主类.

如何在build.sbt中设置mainClass,还是让ScalaJSPlugin不支持此设置？

Answer 1

在mainClass需要对每个配置的基础上设置:

mainClass in Compile := Some("htmlExp.HtmlExpApp")

如果您只是写mainClass := ???,它会mainClass为您的整个项目设置.但是,mainClass检测是基于每个配置.因此,自动检测会覆盖您手动设置.正确覆盖自动检测的唯一方法是mainClass为特定配置设置.

请注意,这根本不是Scala.js所特有的.这同样适用于普通的JVM项目(例如,请参阅此文章).