Add support for version arg

base/src/main/scala/co/uproot/abandon/Config.scala

@@ -18,7 +18,7 @@ class AbandonCLIConf(arguments: Seq[String]) extends ScallopConf(arguments) {
   val filters = propsLong[String]("filter", descr="Transaction filters", keyName=" name")
   val unversioned = opt[Boolean]("unversioned", short = 'X')
   val quiet = opt[Boolean]("quiet", short = 'q')
-  // val trail = trailArg[String]()
+  val version = opt[Boolean]("version", noshort = true)
 }
 
 object SettingsHelper {
@@ -62,9 +62,7 @@ object SettingsHelper {
     }
   }
 
-  def getCompleteSettings(args: Seq[String], version: String): Either[String, Settings] = {
-    val cliConf = new AbandonCLIConf(args)
-    cliConf.verify()
+  def getCompleteSettings(cliConf: AbandonCLIConf, version: String): Either[String, Settings] = {
     val configOpt = cliConf.config.toOption
     val versionId = if (cliConf.unversioned.getOrElse(false)) {
       None
@@ -329,6 +327,8 @@ case class DateRangeConstraint(dateFromOpt: Option[DateBound], dateToOpt: Option
   }
 }
 
+class SettingsError(msg: String) extends RuntimeException(msg)
+
 case class Settings(
   inputs: Seq[String],
   constraints: Seq[Constraint],

cli/src/main/scala/co/uproot/abandon/App.scala

@@ -65,7 +65,7 @@ final class ReportWriter(settings: Settings, outFiles: Seq[String]) {
   }
 }
 
-object CLIMain  {
+object CLIMain {
   def printBalReport(reportWriter: ReportWriter, balanceReport: BalanceReport) = {
     val left = balanceReport.leftEntries.map(_.render)
     val right = balanceReport.rightEntries.map(_.render)
@@ -149,15 +149,16 @@ object CLIMain  {
     }
     reportWriter.endCodeBlock()
   }
+
   def buildId: String = {
     "Base: " + BaseBuildInfo.version + " [" + BaseBuildInfo.builtAtString + "];" +
       "CLI: " + CliBuildInfo.version + " [" + CliBuildInfo.builtAtString + "];"
   }
 
-  def runAppThrows(args: Array[String]) {
-    val settingsResult = SettingsHelper.getCompleteSettings(args, buildId)
+  private def runApp(cliConf: AbandonCLIConf) {
+    val settingsResult = SettingsHelper.getCompleteSettings(cliConf, buildId)
     settingsResult match {
-      case Left(errorMsg) => printErrAndExit(errorMsg)
+      case Left(errorMsg) => throw new SettingsError(errorMsg)
       case Right(settings) =>
         val (parseError, astEntries, processedFiles) = Processor.parseAll(settings.inputs, settings.quiet)
         if (!parseError) {
@@ -225,27 +226,35 @@ object CLIMain  {
     }
   }
 
-  def runApp(args: Array[String]) {
+  def run(args: Array[String]) {
+    val cliConf = new AbandonCLIConf(args)
+    cliConf.verify()
+
+    if (cliConf.version.supplied) {
+      println("Version: " + CliBuildInfo.version + " [" + CliBuildInfo.builtAtString + "]")
+    } else {
+      runApp(cliConf)
+    }
+  }
+
+  def main(args: Array[String]): Unit = {
     try {
-      runAppThrows(args)
+      run(args)
     } catch {
       case a: AssertionError      => printErrAndExit("Internal Assertion Error (please report a bug):" + a.getMessage)
       case i: InputError          => printErrAndExit("Input error: " + i.getMessage)
       case i: ConstraintError     => printErrAndExit("Constraint Failed: " + i.getMessage)
       case e: NotImplementedError => printErrAndExit("Some functionality has not yet been implemented. We intend to implement it eventually. More details:\n" + e.getMessage)
+      case e: SettingsError       => printErrAndExit("Configuration error: " + e.getMessage)
       case e: Error               => printErrAndExit("Unexpected error", e)
     }
   }
 
-  def printErrAndExit(msg: String, err:Error = null) = {
+  private def printErrAndExit(msg: String, err: Error = null) = {
     println(Console.RED + Console.BOLD + msg + Console.RESET)
     if (err != null) {
       err.printStackTrace(Console.out)
     }
     System.exit(1)
   }
 }
-
-object CLIApp extends App {
-   co.uproot.abandon.CLIMain.runApp(args)
-}

cli/src/test/scala/co/uproot/abandon/CLIMainTest.scala

@@ -0,0 +1,11 @@
+package co.uproot.abandon
+
+import org.scalatest.FlatSpec
+
+class CLIMainTest extends FlatSpec {
+
+  behavior of "Abandon CLI with no-op args"
+  it should "handle version" in {
+    co.uproot.abandon.CLIMain.run(Array("--version"))
+  }
+}

cli/src/test/scala/co/uproot/abandon/CliTestRunner.scala

@@ -55,7 +55,7 @@ class CliTestSuite extends FunSuite {
 
   def runTest(tc: TestCase) {
       try {
-        co.uproot.abandon.CLIMain.runAppThrows(Array("-c", tc.conf) ++ tc.args ++ Array("-X", "-q"))
+        co.uproot.abandon.CLIMain.run(Array("-c", tc.conf) ++ tc.args ++ Array("-X", "-q"))
       } catch {
         case x: Exception => println("error: " + x); assert(false)
       }

gui/src/main/scala/co/uproot/abandon/UI.scala

@@ -154,7 +154,15 @@ object AbandonUI extends JFXApp {
   }
 
   try {
-    val settingsResult = SettingsHelper.getCompleteSettings(parameters.raw, buildId)
+    val cliConf = new AbandonCLIConf(parameters.raw)
+    cliConf.verify()
+
+    if (cliConf.version.supplied) {
+      val msg = "Version: " + GuiBuildInfo.version + " [" + GuiBuildInfo.builtAtString + "]"
+      System.err.println(msg)
+    }
+
+    val settingsResult = SettingsHelper.getCompleteSettings(cliConf, buildId)
     settingsResult match {
       case Left(errorMsg) => handleError("Error: " + errorMsg)
       case Right(settings) =>

src/main/scala/co/uproot/abandon/Main.scala

@@ -8,7 +8,7 @@ object Main extends App {
     // ensureJFXIsAvailable()
     AbandonUI.main(args.tail)
   } else {
-    CLIMain.runApp(args)
+    CLIMain.main(args)
   }
 
   private def ensureJFXIsAvailable(): Unit = {