Add exception handling plugin to Ktor HTTP server test

This commit installs a route-scoped plugin that may mask exceptions from OpenTelemetry, if the latter is configured at the wrong phase

Author: rolaca11

instrumentation/ktor/ktor-3.0/library/src/test/kotlin/io/opentelemetry/instrumentation/ktor/v3_0/KtorHttpServerTest.kt

@@ -5,9 +5,13 @@
 
 package io.opentelemetry.instrumentation.ktor.v3_0
 
+import io.ktor.http.HttpStatusCode
 import io.ktor.server.application.*
+import io.ktor.server.application.hooks.CallFailed
+import io.ktor.server.response.respondText
 import io.opentelemetry.instrumentation.testing.junit.InstrumentationExtension
 import io.opentelemetry.instrumentation.testing.junit.http.HttpServerInstrumentationExtension
+import io.opentelemetry.instrumentation.testing.junit.http.ServerEndpoint
 import org.junit.jupiter.api.extension.RegisterExtension
 
 class KtorHttpServerTest : AbstractKtorHttpServerTest() {
@@ -27,6 +31,12 @@ class KtorHttpServerTest : AbstractKtorHttpServerTest() {
         capturedRequestHeaders(TEST_REQUEST_HEADER)
         capturedResponseHeaders(TEST_RESPONSE_HEADER)
       }
+
+      install(createRouteScopedPlugin("Failure handler, that can mask exceptions if exception handling is in the wrong phase", ServerEndpoint.EXCEPTION.path, {}) {
+        on(CallFailed) { call, cause ->
+          call.respondText("failure: ${cause.message}", status = HttpStatusCode.InternalServerError)
+        }
+      })
     }
   }
 }