Strict compiler settings for discovery (#26552)

akka-discovery/src/test/scala/akka/discovery/DiscoveryConfigurationSpec.scala

@@ -143,12 +143,11 @@ class FakeTestDiscovery extends ServiceDiscovery {
 
 class FakeTestDiscovery2 extends FakeTestDiscovery
 
-class DiscoveryException(message: String) extends Exception
+class DiscoveryException(message: String) extends Exception(message)
-
-class ExceptionThrowingDiscovery extends ServiceDiscovery {
-
-  def lookup(lookup: Lookup, resolveTimeout: FiniteDuration): Future[Resolved] = ???
-
-  throw new DiscoveryException("Test Exception")
 
+class ExceptionThrowingDiscovery extends FakeTestDiscovery {
+  bad()
+  def bad(): Unit = {
+    throw new DiscoveryException("oh no")
+  }
 }

akka-discovery/src/test/scala/akka/discovery/aggregate/AggregateServiceDiscoverySpec.scala

@@ -8,6 +8,7 @@ import akka.actor.{ ActorSystem, ExtendedActorSystem }
 import akka.discovery.ServiceDiscovery.{ Resolved, ResolvedTarget }
 import akka.discovery.{ Discovery, Lookup, ServiceDiscovery }
 import akka.testkit.TestKit
+import akka.util.unused
 import com.typesafe.config.{ Config, ConfigFactory }
 import org.scalatest.concurrent.ScalaFutures
 import org.scalatest.{ BeforeAndAfterAll, Matchers, WordSpecLike }
@@ -16,7 +17,7 @@ import scala.concurrent.Future
 import scala.concurrent.duration._
 import scala.collection.immutable
 
-class StubbedServiceDiscovery(system: ExtendedActorSystem) extends ServiceDiscovery {
+class StubbedServiceDiscovery(@unused system: ExtendedActorSystem) extends ServiceDiscovery {
 
   override def lookup(query: Lookup, resolveTimeout: FiniteDuration): Future[Resolved] = {
     if (query.serviceName == "stubbed") {

akka-discovery/src/test/scala/akka/discovery/dns/DnsDiscoverySpec.scala

@@ -48,7 +48,7 @@ class DnsDiscoverySpec extends AkkaSpec(DnsDiscoverySpec.config) with DockerBind
 
   val systemWithAsyncDnsAsResolver = ActorSystem("AsyncDnsSystem", configWithAsyncDnsResolverAsDefault)
 
-  private def testSrvRecords(discovery: ServiceDiscovery): Unit = {
+  private def testSrvRecords(discovery: ServiceDiscovery) = {
     val name = "_service._tcp.foo.test."
 
     def lookup() =
@@ -71,7 +71,7 @@ class DnsDiscoverySpec extends AkkaSpec(DnsDiscoverySpec.config) with DockerBind
     result2.serviceName shouldEqual name
   }
 
-  private def testIpRecords(discovery: ServiceDiscovery): Unit = {
+  private def testIpRecords(discovery: ServiceDiscovery) = {
     val name = "a-single.foo.test"
 
     val expected = Set(ResolvedTarget("192.168.1.20", None, Some(InetAddress.getByName("192.168.1.20"))))

project/AkkaDisciplinePlugin.scala

@@ -19,9 +19,10 @@ object AkkaDisciplinePlugin extends AutoPlugin with ScalafixSupport {
 
   override def trigger: PluginTrigger = allRequirements
   override def requires: Plugins = JvmPlugin && ScalafixPlugin
-
   override lazy val projectSettings = disciplineSettings
   
+  val strictProjects = Set("akka-discovery")
+
   lazy val scalaFixSettings = Seq(
     Compile / scalacOptions += "-Yrangepos")
 
@@ -36,15 +37,18 @@ object AkkaDisciplinePlugin extends AutoPlugin with ScalafixSupport {
   
   lazy val disciplineSettings =
     scalaFixSettings ++
-      scoverageSettings ++ Seq(
+    scoverageSettings ++ Seq(
-      Compile / scalacOptions ++= disciplineScalacOptions,
+      Compile / scalacOptions ++= (if (strictProjects.contains(name.value)) {
-      Compile / scalacOptions --= undisciplineScalacOptions,
+                                 disciplineScalacOptions
+                               } else {
+                                 disciplineScalacOptions -- undisciplineScalacOptions
+                               }).toSeq,
       Compile / console / scalacOptions --= Seq("-deprecation", "-Xfatal-warnings", "-Xlint", "-Ywarn-unused:imports"),
       // Discipline is not needed for the docs compilation run (which uses
       // different compiler phases from the regular run), and in particular
       // '-Ywarn-unused:explicits' breaks 'sbt ++2.13.0-M5 akka-actor/doc'
       // https://github.com/akka/akka/issues/26119
-      Compile / doc / scalacOptions --= disciplineScalacOptions,
+      Compile / doc / scalacOptions --= disciplineScalacOptions.toSeq,
       Compile / scalacOptions --= (CrossVersion.partialVersion(scalaVersion.value) match {
         case Some((2, 13)) =>
           Seq(
@@ -66,14 +70,14 @@ object AkkaDisciplinePlugin extends AutoPlugin with ScalafixSupport {
   /**
     * Remain visibly filtered for future code quality work and removing.
     */
-  val undisciplineScalacOptions = Seq(
+  val undisciplineScalacOptions = Set(
     "-Ywarn-value-discard",
     "-Ywarn-numeric-widen",
     "-Yno-adapted-args",
     "-Xfatal-warnings")
 
   /** These options are desired, but some are excluded for the time being*/
-  val disciplineScalacOptions = Seq(
+  val disciplineScalacOptions = Set(
     // start: must currently remove, version regardless
     "-Xfatal-warnings",
     "-Ywarn-value-discard",