Fix nested http.route (#8282)

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/spring/webflux/v5_0/server/HandlerAdapterInstrumentation.java

@@ -65,8 +65,12 @@ public class HandlerAdapterInstrumentation implements TypeInstrumentation {
 
       Context parentContext = Context.current();
 
+      // HttpRouteSource.CONTROLLER has useFirst true, and it will update http.route only once
+      // using the last portion of the nested path.
+      // HttpRouteSource.NESTED_CONTROLLER has useFirst false, and it will make http.route updated
+      // twice: 1st using the last portion of the nested path, 2nd time using the full nested path.
       HttpRouteHolder.updateHttpRoute(
-          parentContext, HttpRouteSource.CONTROLLER, httpRouteGetter(), exchange);
+          parentContext, HttpRouteSource.NESTED_CONTROLLER, httpRouteGetter(), exchange);
 
       if (handler == null) {
         return;

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/test/java/server/base/ImmediateHandlerSpringWebFluxServerTest.java

@@ -5,7 +5,14 @@
 
 package server.base;
 
+import static io.opentelemetry.instrumentation.testing.junit.http.ServerEndpoint.NESTED_PATH;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
 import io.opentelemetry.instrumentation.testing.junit.http.ServerEndpoint;
+import io.opentelemetry.testing.internal.armeria.common.AggregatedHttpRequest;
+import io.opentelemetry.testing.internal.armeria.common.AggregatedHttpResponse;
+import org.junit.jupiter.api.Test;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.web.embedded.netty.NettyReactiveWebServerFactory;
 import org.springframework.context.annotation.Bean;
@@ -54,4 +61,18 @@ public class ImmediateHandlerSpringWebFluxServerTest extends HandlerSpringWebFlu
           });
     }
   }
+
+  @Test
+  void nestedPath() {
+    assumeTrue(Boolean.getBoolean("testLatestDeps"));
+
+    String method = "GET";
+    AggregatedHttpRequest request = request(NESTED_PATH, method);
+    AggregatedHttpResponse response = client.execute(request).aggregate().join();
+    assertThat(response.status().code()).isEqualTo(NESTED_PATH.getStatus());
+    assertThat(response.contentUtf8()).isEqualTo(NESTED_PATH.getBody());
+    assertResponseHasCustomizedHeaders(response, NESTED_PATH, null);
+
+    assertTheTraces(1, null, null, null, method, NESTED_PATH, response);
+  }
 }

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/test/java/server/base/ServerTestController.java

@@ -116,6 +116,18 @@ public abstract class ServerTestController {
         });
   }
 
+  @GetMapping("/nestedPath")
+  public Mono<String> nested_path(ServerHttpRequest request, ServerHttpResponse response) {
+    ServerEndpoint endpoint = ServerEndpoint.NESTED_PATH;
+
+    return wrapControllerMethod(
+        endpoint,
+        () -> {
+          setStatus(response, endpoint);
+          return endpoint.getBody();
+        });
+  }
+
   protected abstract <T> Mono<T> wrapControllerMethod(ServerEndpoint endpoint, Supplier<T> handler);
 
   private static void setStatus(ServerHttpResponse response, ServerEndpoint endpoint) {

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/test/java/server/base/ServerTestRouteFactory.java

@@ -6,6 +6,8 @@
 package server.base;
 
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
+import static org.springframework.web.reactive.function.server.RouterFunctions.nest;
 import static org.springframework.web.reactive.function.server.RouterFunctions.route;
 
 import io.opentelemetry.api.trace.Span;
@@ -98,7 +100,17 @@ public abstract class ServerTestRouteFactory {
                           request.headers().asHttpHeaders().getFirst("X-Test-Request")),
                   null,
                   null);
-            });
+            })
+        .andNest(
+            path("/nestedPath"),
+            nest(
+                path("/hello"),
+                route(
+                    path("/world"),
+                    request -> {
+                      ServerEndpoint endpoint = ServerEndpoint.NESTED_PATH;
+                      return respond(endpoint, null, null, null);
+                    })));
   }
 
   protected Mono<ServerResponse> respond(

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/test/java/server/base/SpringWebFluxServerTest.java

@@ -52,6 +52,8 @@ public abstract class SpringWebFluxServerTest
         return getContextPath() + "/path/{id}/param";
       case NOT_FOUND:
         return "/**";
+      case NESTED_PATH:
+        return "/nestedPath/hello/world";
       default:
         return super.expectedHttpRoute(endpoint);
     }

testing-common/src/main/java/io/opentelemetry/instrumentation/testing/junit/http/AbstractHttpServerTest.java

@@ -94,7 +94,7 @@ public abstract class AbstractHttpServerTest<SERVER> extends AbstractHttpServerU
     return GlobalTraceUtil.runWithSpan("controller", () -> closure.get());
   }
 
-  private AggregatedHttpRequest request(ServerEndpoint uri, String method) {
+  protected AggregatedHttpRequest request(ServerEndpoint uri, String method) {
     return AggregatedHttpRequest.of(HttpMethod.valueOf(method), resolveAddress(uri));
   }
 

testing-common/src/main/java/io/opentelemetry/instrumentation/testing/junit/http/ServerEndpoint.java

@@ -19,6 +19,11 @@ public enum ServerEndpoint {
   EXCEPTION("exception", 500, "controller exception"),
   NOT_FOUND("notFound", 404, "not found"),
   CAPTURE_HEADERS("captureHeaders", 200, "headers captured"),
+  NESTED_PATH(
+      "nestedPath/hello/world",
+      200,
+      "nested path"), // TODO (heya) move it to webflux test module after this has been converted to
+  // a class
   CAPTURE_PARAMETERS("captureParameters", 200, "parameters captured"),
 
   // TODO: add tests for the following cases: