FetchMainClassForAllVersions.sc

import $ivy.`io.get-coursier::coursier:2.0.0-RC6-21`
import coursier._
import java.io.File
import java.io.FileInputStream
import scala.concurrent.ExecutionContext
def extractMainClassName(file: File): Option[String] = {
  val jarStream =
    new java.util.jar.JarInputStream(new FileInputStream(file))
  val mf = jarStream.getManifest
  Option(mf.getMainAttributes).flatMap(attrs =>
    Option(attrs.getValue("Main-Class"))
  )
}
def fetchDependencyMainClassUnsafe(d: Dependency): List[String] =
  Fetch()
    .addDependencies(d)
    .run()
    .filter(_.getName == s"${d.module.name.value}-${d.version}.jar")
    .toList
    .flatMap(extractMainClassName)
def fetchVersionsUnsafe(module: Module): List[String] =
  Versions()
    .withModule(module)
    .result()
    .unsafeRun()(ExecutionContext.global)
    .results
    .collect { case (_, Right(value)) => value }
    .flatMap(_.available)
    .toList
val module = Module(
  Organization("io.swagger.codegen.v3"),
  ModuleName("swagger-codegen-cli")
)
fetchVersionsUnsafe(module)
  .foreach { version =>
    val mainClassOpt =
      fetchDependencyMainClassUnsafe(Dependency(module, version))
    println(s"$version: $mainClassOpt")
  }