Enable fatal errors for docs (#29570)

akka-docs/src/test/scala/docs/stream/operators/SourceOperators.scala

@@ -4,7 +4,6 @@
 
 package docs.stream.operators
 
-import akka.Done
 import akka.actor.ActorSystem
 import akka.testkit.TestProbe
 
@@ -12,7 +11,7 @@ object SourceOperators {
 
   implicit val system: ActorSystem = ???
 
-  def fromFuture = {
+  def fromFuture(): Unit = {
     //#sourceFromFuture
 
     import akka.actor.ActorSystem
@@ -35,7 +34,6 @@ object SourceOperators {
     import akka.stream.OverflowStrategy
     import akka.stream.CompletionStrategy
     import akka.stream.scaladsl._
-    import scala.util.Failure
 
     val source: Source[Any, ActorRef] = Source.actorRef(
       completionMatcher = {

akka-docs/src/test/scala/docs/stream/operators/converters/StreamConvertersToJava.scala

@@ -36,10 +36,10 @@ class StreamConvertersToJava extends AkkaSpec with Futures {
   "demonstrate conversion from Java8 streams" in {
     //#fromJavaStream
     def factory(): IntStream = IntStream.rangeClosed(0, 9)
-    val source: Source[Int, NotUsed] = StreamConverters.fromJavaStream(factory).map(_.intValue())
+    val source: Source[Int, NotUsed] = StreamConverters.fromJavaStream(() => factory()).map(_.intValue())
     val sink: Sink[Int, Future[immutable.Seq[Int]]] = Sink.seq[Int]
 
-    val futureInts: Future[immutable.Seq[Int]] = source.toMat(sink)(Keep.right).run
+    val futureInts: Future[immutable.Seq[Int]] = source.toMat(sink)(Keep.right).run()
 
     //#fromJavaStream
     whenReady(futureInts) { ints =>

akka-docs/src/test/scala/docs/stream/operators/flow/FromSinkAndSource.scala

@@ -16,9 +16,6 @@ import akka.stream.scaladsl.Source
 import akka.stream.scaladsl.Tcp
 import akka.stream.testkit.TestPublisher
 import akka.stream.testkit.TestSubscriber
-import akka.stream.testkit.Utils.TE
-import akka.stream.testkit.scaladsl.TestSource
-import akka.stream.testkit.scaladsl.TestSink
 import akka.util.ByteString
 
 import scala.concurrent.duration._
@@ -63,7 +60,7 @@ object FromSinkAndSource {
   def testing(): Unit = {
     def myApiThatTakesAFlow[In, Out](flow: Flow[In, Out, NotUsed]): Unit = ???
     // #testing
-    val inProbe = TestSubscriber.probe[String]
+    val inProbe = TestSubscriber.probe[String]()
     val outProbe = TestPublisher.probe[String]()
     val testFlow = Flow.fromSinkAndSource(Sink.fromSubscriber(inProbe), Source.fromPublisher(outProbe))
 

akka-docs/src/test/scala/docs/stream/operators/source/Restart.scala

@@ -52,7 +52,7 @@ object Restart extends App {
 
   }
 
-  def onRestartWithBackoffInnerComplete() {
+  def onRestartWithBackoffInnerComplete() = {
 
     //#restart-failure-inner-complete
     val finiteSource = Source.tick(1.second, 1.second, "tick").take(3)

akka-docs/src/test/scala/docs/stream/operators/source/Tick.scala

@@ -27,7 +27,7 @@ object Tick {
     case class Response(text: String)
   }
 
-  def simple() {
+  def simple() = {
     // #simple
     Source
       .tick(
@@ -39,7 +39,7 @@ object Tick {
     // #simple
   }
 
-  def pollSomething() {
+  def pollSomething() = {
     // #poll-actor
     val periodicActorResponse: Source[String, Cancellable] = Source
       .tick(1.second, 1.second, "tick")

akka-docs/src/test/scala/docs/stream/operators/source/Zip.scala

@@ -4,7 +4,6 @@
 
 package docs.stream.operators.source
 
-import akka.NotUsed
 import akka.actor.typed.ActorSystem
 import akka.stream.scaladsl.Source
 
@@ -48,7 +47,7 @@ object Zip {
     // #zipWithN-simple
   }
 
-  def zipAll() {
+  def zipAll() = {
     // #zipAll-simple
     val numbers = Source(1 :: 2 :: 3 :: 4 :: Nil)
     val letters = Source("a" :: "b" :: "c" :: Nil)