Add tapir routes test to verify fix

Prior to adding the on exit finalization logic to the Future,
this test failed because of an NPE thrown because
PekkoRouteHolder.restore was called in the wrong order.

Author: masonedmison

instrumentation/pekko/pekko-http-1.0/javaagent/build.gradle.kts

@@ -31,6 +31,8 @@ dependencies {
   library("org.apache.pekko:pekko-http_2.12:1.0.0")
   library("org.apache.pekko:pekko-stream_2.12:1.0.1")
 
+  testImplementation("com.softwaremill.sttp.tapir:tapir-pekko-http-server_2.12:1.7.0")
+
   testInstrumentation(project(":instrumentation:pekko:pekko-actor-1.0:javaagent"))
   testInstrumentation(project(":instrumentation:executors:javaagent"))
 

instrumentation/pekko/pekko-http-1.0/javaagent/src/test/scala/io/opentelemetry/javaagent/instrumentation/pekkohttp/v1_0/PekkoHttpServerRouteTest.scala

@@ -31,8 +31,10 @@ import org.junit.jupiter.api.{AfterAll, Test, TestInstance}
 
 import java.net.{URI, URISyntaxException}
 import java.util.function.Consumer
-import scala.concurrent.Await
+import scala.concurrent.{Await, ExecutionContext, Future}
 import scala.concurrent.duration.DurationInt
+import sttp.tapir._
+import sttp.tapir.server.pekkohttp.PekkoHttpServerInterpreter
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 class PekkoHttpServerRouteTest {
@@ -77,6 +79,30 @@ class PekkoHttpServerRouteTest {
     test(route, "/test/1", "GET /test/*")
   }
 
+  @Test def testTapirRoutes(): Unit = {
+    val interpreter = PekkoHttpServerInterpreter()(system.dispatcher)
+    def makeRoute(input: EndpointInput[Unit]) = {
+      interpreter.toRoute(
+        endpoint.get
+          .in(input)
+          .errorOut(stringBody)
+          .out(stringBody)
+          .serverLogicPure[Future](_ => Right("ok"))
+      )
+    }
+
+    val route1 = makeRoute("test" / "1")
+    val route2 = makeRoute("test" / "2")
+    val route3 = makeRoute("test" / "3")
+    val route4 = makeRoute("test" / "4")
+
+    val routes1 = concat(route1, route2)
+    val routes2 = concat(route3, route4)
+    val routes = concat(routes1, routes2)
+
+    test(routes, "/test/4", "GET")
+  }
+
   def test(route: Route, path: String, spanName: String): Unit = {
     val port = PortUtils.findOpenPort
     val address: URI = buildAddress(port)