Remove unused Error class

Test toolkit default and warnings for latest

Author: MaciejG604

modules/cli/src/main/scala/scala/cli/commands/shared/SharedOptions.scala

@@ -22,8 +22,7 @@ import scala.build.errors.{
   AmbiguousPlatformError,
   BuildException,
   ConfigDbException,
-  Severity,
-  ToolkitOptionMissingVersionError
+  Severity
 }
 import scala.build.input.{Element, Inputs, ResourceDirectory, ScalaCliInvokeData}
 import scala.build.interactive.Interactive
@@ -399,13 +398,13 @@ final case class SharedOptions(
           SharedOptions.parseDependencies(
             dependencies.dependency.map(Positioned.none),
             ignoreErrors
-          ) ++ value(SharedOptions.resolveToolkitDependency(withToolkit, logger))
+          ) ++ SharedOptions.resolveToolkitDependency(withToolkit, logger)
         ),
         extraCompileOnlyDependencies = ShadowingSeq.from(
           SharedOptions.parseDependencies(
             dependencies.compileOnlyDependency.map(Positioned.none),
             ignoreErrors
-          ) ++ value(SharedOptions.resolveToolkitDependency(withToolkit, logger))
+          ) ++ SharedOptions.resolveToolkitDependency(withToolkit, logger)
         )
       ),
       internal = bo.InternalOptions(
@@ -728,22 +727,17 @@ object SharedOptions {
   private def resolveToolkitDependency(
     toolkitVersion: Option[String],
     logger: Logger
-  ): Either[BuildException, Seq[Positioned[AnyDependency]]] =
-    if (toolkitVersion.contains(""))
-      Left(ToolkitOptionMissingVersionError("an empty string"))
-    else {
-      if (
-        toolkitVersion.contains("latest") || toolkitVersion.contains(Toolkit.typelevel + ":latest")
+  ): Seq[Positioned[AnyDependency]] = {
+    if (
+      toolkitVersion.contains("latest") || toolkitVersion.contains(Toolkit.typelevel + ":latest")
+    )
+      logger.message(
+        s"""WARNING: using 'latest' for toolkit is deprecated, use 'default' to get more stable behaviour:
+           | --toolkit ${toolkitVersion.map(_.replace("latest", "default")).getOrElse("default")}
+           |""".stripMargin
       )
-        logger.message(
-          s"""WARNING: using 'latest' for toolkit is deprecated, use 'default' to get more stable behaviour:
-             | --toolkit ${toolkitVersion.map(_.replace("latest", "default")).getOrElse("default")}
-             |""".stripMargin
-        )
 
-      Right(
-        toolkitVersion.toList.map(Positioned.commandLine)
-          .flatMap(Toolkit.resolveDependenciesWithRequirements(_).map(_.value))
-      )
-    }
+    toolkitVersion.toList.map(Positioned.commandLine)
+      .flatMap(Toolkit.resolveDependenciesWithRequirements(_).map(_.value))
+  }
 }

modules/core/src/main/scala/scala/build/errors/ToolkitOptionMissingVersionError.scala

@@ -272,7 +272,7 @@ trait RunScalaJsTestDefinitions { _: RunTestDefinitions =>
     val msg = "Hello"
     TestInputs(
       os.rel / "script.sc" ->
-        s"""//> using toolkit latest
+        s"""//> using toolkit default
            |//> using platform "scala-js"
            |import scala.scalajs.js
            |val console = js.Dynamic.global.console

modules/integration/src/test/scala/scala/cli/integration/RunScalaJsTestDefinitions.scala

@@ -304,7 +304,7 @@ trait RunScalaNativeTestDefinitions { _: RunTestDefinitions =>
   test("native defaults & toolkit latest") {
     TestInputs(
       os.rel / "script.sc" ->
-        """//> using toolkit latest
+        """//> using toolkit default
           |//> using platform "scala-native"
           |println(os.pwd)
           |""".stripMargin