Fix #8340: Add regression test

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/build.sbt

@@ -0,0 +1,6 @@
+val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
+
+scalaVersion := "3.3.4"
+Test / fork := true
+libraryDependencies += scalatest % Test
+

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/src/main/resources/META-INF/services/example.Service

@@ -0,0 +1,2 @@
+example.ServiceImpl
+

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/src/main/scala/example/Service.scala

@@ -0,0 +1,6 @@
+package example
+
+trait Service {
+  def name: String
+}
+

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/src/main/scala/example/ServiceImpl.scala

@@ -0,0 +1,6 @@
+package example
+
+class ServiceImpl extends Service {
+  override def name: String = "MyServiceImpl"
+}
+

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/src/test/scala/example/ServiceTest.scala

@@ -0,0 +1,16 @@
+package example
+
+import org.scalatest.funsuite.AnyFunSuite
+import java.util.ServiceLoader
+import scala.jdk.CollectionConverters._
+
+class ServiceTest extends AnyFunSuite {
+  test("ServiceLoader should find service implementation when Test / fork := true") {
+    val services = ServiceLoader.load(classOf[Service])
+    val iterator = services.iterator()
+    assert(iterator.hasNext, "ServiceLoader should find at least one service")
+    val service = iterator.next()
+    assert(service.name == "MyServiceImpl", s"Expected service name 'MyServiceImpl', got '${service.name}'")
+  }
+}
+

sbt-app/src/sbt-test/tests/i8340-serviceloader-fork/test

@@ -0,0 +1 @@
+> test