Fix plugin for Scala 3 projects (#76)

Our previous logic relied on withDefaultValue in the Scalameta version
map to get the version of scalameta plugin.

Issue is, withDefaultValue does not affect .get operations:

```scala
Welcome to Scala 2.12.18 (OpenJDK 64-Bit Server VM, Java 17.0.6).
Type in expressions for evaluation. Or try :help.

scala> val mp = Map("a" -> 2).withDefaultValue(3)
mp: scala.collection.immutable.Map[String,Int] = Map(a -> 2)

scala> mp.get("c")
res0: Option[Int] = None
```

Moreover, we don't need to add semanticdb plugin at all if we're working
on a Scala 3 project.

This comment fixes the logic to be explicit about Scala 3.

Additionally, we amend the semanticdb parameters used to customise
output location, according to https://github.com/sbt/sbt/blob/1.9.x/main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala#L92

* Clean up the build

1. Remove Java 17-ism
2. Upgrade SBT to 1.9.3
3. Remove sbt-bloop (it's added automatically by metals)

Author: keynmol

build.sbt

@@ -51,7 +51,9 @@ Compile / resourceGenerators += Def.task {
   if (!out.exists()) {
     val versions = Versions.semanticdbVersionsByScalaVersion()
     val props = new Properties()
-    props.putAll(versions.asJava)
+    versions.foreach { case (k, v) =>
+      props.put(k, v)
+    }
     IO.write(props, "SemanticDB versions grouped by Scala version.", out)
   }
   List(out)
@@ -84,3 +86,4 @@ scriptedLaunchOpts ++= Seq(
 )
 
 def isCI = "true" == System.getenv("CI")
+ThisBuild / version := { if (!isCI) "dev" else version.value }

project/build.properties

@@ -1 +1 @@
-sbt.version=1.5.2
+sbt.version=1.9.3

project/plugins.sbt

@@ -2,7 +2,6 @@ addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.5")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.10.0")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.3")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.29")
-addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1.4.9-22-2d02726c")
 
 libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value
 

src/main/scala/com/sourcegraph/sbtsourcegraph/SourcegraphEnable.scala

@@ -25,9 +25,11 @@ object SourcegraphEnable {
         |2. conditionally sets semanticdbVersion & scalaVersion when support is not built-in in the compiler""".stripMargin
   ) { s =>
     val extracted = Project.extract(s)
+
     val scalacOptionsSettings = Seq(Compile, Test).flatMap(
       inConfig(_)(SourcegraphPlugin.relaxScalacOptionsConfigSettings)
     )
+
     val semanticdbJavacVersion = Versions.semanticdbJavacVersion()
     val settings = for {
       (p, semanticdbVersion, overriddenScalaVersion) <- collectProjects(
@@ -47,13 +49,16 @@ object SourcegraphEnable {
           ),
           overriddenScalaVersion.map(v => scalaVersion.in(p) := v),
           Option(SemanticdbPlugin.semanticdbEnabled.in(p) := true),
-          Option(SemanticdbPlugin.semanticdbVersion.in(p) := semanticdbVersion)
+          semanticdbVersion.map(ver =>
+            SemanticdbPlugin.semanticdbVersion.in(p) := ver
+          )
         ).flatten
       settings <-
         inScope(ThisScope.in(p))(
           scalacOptionsSettings
         ) ++ enableSemanticdbPlugin
     } yield settings
+
     Compat.append(extracted, settings, s)
   }
 
@@ -88,11 +93,14 @@ object SourcegraphEnable {
           scalaVersion.in(p) := v
         },
         Option(
-          allDependencies.in(p) += compilerPlugin(
-            SourcegraphPlugin.autoImport.sourcegraphSemanticdb(
-              semanticdbVersion
-            )
-          )
+          allDependencies.in(p) ++=
+            semanticdbVersion.map { ver =>
+              compilerPlugin(
+                SourcegraphPlugin.autoImport.sourcegraphSemanticdb(
+                  ver
+                )
+              )
+            }.toSeq
         )
       ).flatten
       settings <-
@@ -105,8 +113,8 @@ object SourcegraphEnable {
 
   private val semanticdbConfigSettings: Seq[Def.Setting[_]] =
     Seq(
-      scalacOptions.in(compile) := {
-        val old = scalacOptions.in(compile).value
+      scalacOptions := {
+        val old = scalacOptions.value
         val options = List(
           "-Yrangepos",
           "-Xplugin-require:semanticdb"
@@ -119,7 +127,7 @@ object SourcegraphEnable {
 
   private def collectProjects[U](
       extracted: Extracted
-  ): Seq[(ProjectRef, String, Option[String])] = for {
+  ): Seq[(ProjectRef, Option[String], Option[String])] = for {
     p <- extracted.structure.allProjectRefs
     projectScalaVersion <- scalaVersion
       .in(p)
@@ -132,8 +140,7 @@ object SourcegraphEnable {
       )
         Some("2.11.12")
       else None
-    semanticdbVersion <- Versions
+    semanticdbVersion = Versions
       .semanticdbVersion(overriddenScalaVersion.getOrElse(projectScalaVersion))
-      .toList
   } yield (p, semanticdbVersion, overriddenScalaVersion)
 }

src/main/scala/com/sourcegraph/sbtsourcegraph/SourcegraphPlugin.scala

@@ -180,13 +180,26 @@ object SourcegraphPlugin extends AutoPlugin {
   def configSettings: Seq[Def.Setting[_]] = List(
     sourcegraphUpload := sourcegraphUpload.value,
     sourcegraphScalacTargetroot := {
-      val customDirectory = (for {
-        option <- scalacOptions.value
-        if option.startsWith("-P:semanticdb:targetroot:")
-      } yield new File(
-        option.stripPrefix("-P:semanticdb:targetroot:")
-      )).lastOption
-      customDirectory.getOrElse(classDirectory.value)
+      val scala2Prefix = "-P:semanticdb:targetroot:"
+      val scala3Prefix = "-semanticdb-target"
+
+      val customDirectory = scalacOptions.value
+        .collectFirst {
+          case flag if flag.startsWith(scala2Prefix) =>
+            flag.stripPrefix(scala2Prefix)
+          case flag if flag.startsWith(scala3Prefix) =>
+            flag.stripPrefix(scala3Prefix)
+        }
+        .map(new File(_))
+
+      lazy val root = SemanticdbPlugin.semanticdbTargetRoot.?.value
+
+      val explicitRoot =
+        if (SemanticdbPlugin.isAvailable())
+          root
+        else None
+
+      explicitRoot.orElse(customDirectory).getOrElse(classDirectory.value)
     },
     sourcegraphJavacTargetroot := {
       (for {

src/main/scala/com/sourcegraph/sbtsourcegraph/Versions.scala

@@ -15,7 +15,12 @@ object Versions {
       throw new NoSuchElementException(semanticdbJavacKey)
     )
   def semanticdbVersion(scalaVersion: String): Option[String] =
-    cachedSemanticdbVersionsByScalaVersion.get(scalaVersion)
+    // Scala 3 has semanticdb generation built in, so we don't need to
+    // add the semanticdb-scalac plugin
+    if (scalaVersion.startsWith("3."))
+      None
+    else
+      cachedSemanticdbVersionsByScalaVersion.get(scalaVersion)
   lazy val cachedSemanticdbVersionsByScalaVersion: Map[String, String] = {
     val key = "/sbt-sourcegraph/semanticdb.properties"
     val in = this.getClass().getResourceAsStream(key)

src/sbt-test/sbt-sourcegraph/scala-3/build.sbt

@@ -0,0 +1 @@
+scalaVersion := "3.3.0"

src/sbt-test/sbt-sourcegraph/scala-3/project/build.properties

@@ -0,0 +1 @@
+sbt.version=1.9.3

src/sbt-test/sbt-sourcegraph/scala-3/project/plugins.sbt

@@ -0,0 +1,6 @@
+addSbtPlugin(
+  "com.sourcegraph" % "sbt-sourcegraph" % sys.props("plugin.version")
+)
+
+libraryDependencies += "com.sourcegraph" % "scip-semanticdb" %
+  sys.props("scip-java.version")

src/sbt-test/sbt-sourcegraph/scala-3/src/main/scala/Test.scala

@@ -0,0 +1,4 @@
+object Hello:
+  def world() = ""
+
+@main def entrypoint = println(Hello.world())