bake in version info

.github/workflows/release.yml

@@ -18,9 +18,12 @@ jobs:
           java-version: '8'
           cache: 'sbt'
 
+      - name: Extract version from tag
+        run: echo "PROJECT_VERSION=${GITHUB_REF#refs/tags/v}" >> $GITHUB_ENV
+
       - name: Build JAR
         run: |
-          sbt assembly
+          sbt 'set version := "'"$PROJECT_VERSION"'"' assembly
           mv target/scala-2.11/*-assembly-*.jar royalroad-downloader.jar
 
       - name: Release

build.sbt

@@ -10,5 +10,14 @@ libraryDependencies += "org.rogach" %% "scallop" % "1.0.1"
 libraryDependencies += "org.scalatest" %% "scalatest" % "3.0.5" % "test"
 libraryDependencies += "org.scala-lang.modules" % "scala-java8-compat_2.11" % "0.9.1"
 
+// inject version info
+resourceGenerators in Compile += Def.task {
+  val file = (resourceManaged in Compile).value / "version.properties"
+  val props = new java.util.Properties()
+  props.put("version", version.value)
+  IO.write(props, "Version information", file)
+  Seq(file)
+}.taskValue
+
 mainClass in (Compile, run) := Some("com.aivean.royalroad.Main")
 mainClass in assembly := Some("com.aivean.royalroad.Main")

src/main/scala/com/aivean/royalroad/Main.scala

@@ -14,6 +14,8 @@ import scala.concurrent.{Await, Future, duration}
 
 object Main extends App {
 
+  print ("Royalroad downloader v" + VersionInfo.version + "\n")
+
   def handleFromArg[T](chaps: Seq[T], fromChap: Int): Seq[T] =
     if (fromChap > 0) chaps.drop(fromChap - 1) else if (fromChap < 0) chaps.takeRight(-fromChap) else chaps
 

src/main/scala/com/aivean/royalroad/VersionInfo.scala

@@ -0,0 +1,11 @@
+package com.aivean.royalroad
+
+object VersionInfo {
+  lazy val version: String = try {
+    val props = new java.util.Properties()
+    props.load(getClass.getResourceAsStream("/version.properties"))
+    props.getProperty("version")
+  } catch {
+    case _: Throwable => "unknown"
+  }
+}