Add --version output. (#100)

Author: balhoff

build.sbt

@@ -1,4 +1,6 @@
 enablePlugins(JavaAppPackaging)
+enablePlugins(BuildInfoPlugin)
+enablePlugins(GitVersioning)
 
 organization := "org.renci"
 
@@ -16,6 +18,14 @@ javaOptions += "-Xmx8G"
 
 testFrameworks += new TestFramework("zio.test.sbt.ZTestFramework")
 
+val gitCommitString = SettingKey[String]("gitCommit")
+
+gitCommitString := git.gitHeadCommit.value.getOrElse("Not Set")
+
+buildInfoKeys := Seq[BuildInfoKey](name, version, scalaVersion, sbtVersion, gitCommitString)
+
+buildInfoPackage := "org.renci.relationgraph"
+
 val zioVersion = "1.0.13"
 
 libraryDependencies ++= {

project/plugins.sbt

@@ -1 +1,3 @@
 addSbtPlugin("com.github.sbt" % "sbt-native-packager" % "1.9.7")
+addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.10.0")
+addSbtPlugin("com.typesafe.sbt" % "sbt-git" % "1.0.2")

src/main/scala/org/renci/relationgraph/ZCaseApp.scala

@@ -11,8 +11,8 @@ import zio.console.{Console, putStrLn}
 import java.io.IOException
 
 /**
-  * Adapted from caseapp.cats.IOCaseApp
-  */
+ * Adapted from caseapp.cats.IOCaseApp
+ */
 abstract class ZCaseApp[T](implicit val parser0: Parser[T], val messages: Help[T]) extends App {
 
   private[this] def parser: Parser[T] = {
@@ -35,42 +35,44 @@ abstract class ZCaseApp[T](implicit val parser0: Parser[T], val messages: Help[T
     putStrLn(messages.withHelp.usage).as(ExitCode.success)
 
   /**
-    * Arguments are expanded then parsed. By default, argument expansion is the identity function.
-    * Overriding this method allows plugging in an arbitrary argument expansion logic.
-    *
-    * One such expansion logic involves replacing each argument of the form '@<file>' with the
-    * contents of that file where each line in the file becomes a distinct argument.
-    * To enable this behavior, override this method as shown below.
-    *
-    * @example
-    * {{{
-    * import caseapp.core.parser.PlatformArgsExpander
-    * override def expandArgs(args: List[String]): List[String]
-    * = PlatformArgsExpander.expand(args)
-    * }}}
-    * @param args
-    * @return
-    */
+   * Arguments are expanded then parsed. By default, argument expansion is the identity function.
+   * Overriding this method allows plugging in an arbitrary argument expansion logic.
+   *
+   * One such expansion logic involves replacing each argument of the form '@<file>' with the
+   * contents of that file where each line in the file becomes a distinct argument.
+   * To enable this behavior, override this method as shown below.
+   *
+   * @example
+   * {{{
+   * import caseapp.core.parser.PlatformArgsExpander
+   * override def expandArgs(args: List[String]): List[String]
+   * = PlatformArgsExpander.expand(args)
+   * }}}
+   * @param args
+   * @return
+   */
   private[this] def expandArgs(args: List[String]): List[String] = args
 
   /**
-    * Whether to stop parsing at the first unrecognized argument.
-    *
-    * That is, stop parsing at the first non option (not starting with "-"), or
-    * the first unrecognized option. The unparsed arguments are put in the `args`
-    * argument of `run`.
-    */
+   * Whether to stop parsing at the first unrecognized argument.
+   *
+   * That is, stop parsing at the first non option (not starting with "-"), or
+   * the first unrecognized option. The unparsed arguments are put in the `args`
+   * argument of `run`.
+   */
   private[this] def stopAtFirstUnrecognized: Boolean = false
 
   private[this] def nameFormatter: Formatter[Name] = Formatter.DefaultNameFormatter
 
-  override def run(args: List[String]): ZIO[ZEnv, Nothing, ExitCode] =
-    parser.withHelp.detailedParse(expandArgs(args), stopAtFirstUnrecognized) match {
-      case Left(err) => error(err).orDie
-      case Right((WithHelp(_, true, _), _)) => helpAsked.orDie
-      case Right((WithHelp(true, _, _), _)) => usageAsked.orDie
-      case Right((WithHelp(_, _, Left(err)), _)) => error(err).orDie
+  override def run(args: List[String]): ZIO[ZEnv, Nothing, ExitCode] = {
+    if (args == List("--version")) ZIO.succeed(println(org.renci.relationgraph.BuildInfo.toString)).exitCode
+    else parser.withHelp.detailedParse(expandArgs(args), stopAtFirstUnrecognized) match {
+      case Left(err)                                        => error(err).orDie
+      case Right((WithHelp(_, true, _), _))                 => helpAsked.orDie
+      case Right((WithHelp(true, _, _), _))                 => usageAsked.orDie
+      case Right((WithHelp(_, _, Left(err)), _))            => error(err).orDie
       case Right((WithHelp(_, _, Right(t)), remainingArgs)) => run(t, remainingArgs)
     }
+  }
 
 }