fix: bound native shutdown and close connections that become idle during drain

app/transport_test.go

@@ -264,3 +264,59 @@ func TestRunWithRemainsIndependentOfBuiltInTransport(t *testing.T) {
 		}
 	}
 }
+
+func TestConfiguredShutdownDoesNotWaitForUncooperativeHandler(t *testing.T) {
+	for _, transport := range []string{config.TransportNetHTTP, config.TransportNative, config.TransportHTTP2} {
+		t.Run(transport, func(t *testing.T) {
+			cert, key, tlsClient := testutil.CertificateFiles(t)
+			application := New(config.WithTransport(transport), config.WithTLS(cert, key), config.WithShutdownTimeout(80*time.Millisecond))
+			started := make(chan context.Context, 1)
+			release, finished := make(chan struct{}), make(chan struct{})
+			application.GET("/blocked", func(ctx *httpx.Context) error {
+				defer close(finished)
+				started <- ctx.Context()
+				<-release
+				return nil
+			})
+			listener, err := net.Listen("tcp", "127.0.0.1:0")
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer listener.Close()
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			done := make(chan error, 1)
+			go func() { done <- application.ServeContext(ctx, listener) }()
+			client := &http.Client{Timeout: 3 * time.Second, Transport: &http.Transport{TLSClientConfig: tlsClient, ForceAttemptHTTP2: true}}
+			defer client.CloseIdleConnections()
+			requestDone := make(chan struct{})
+			go func() {
+				defer close(requestDone)
+				response, err := client.Get("https://" + listener.Addr().String() + "/blocked")
+				if err == nil {
+					response.Body.Close()
+				}
+			}()
+			var requestContext context.Context
+			select {
+			case requestContext = <-started:
+			case <-time.After(3 * time.Second):
+				close(release)
+				t.Fatal("handler did not start")
+			}
+			defer func() { close(release); await(t, finished) }()
+			cancel()
+			select {
+			case err := <-done:
+				if !errors.Is(err, context.DeadlineExceeded) {
+					t.Fatalf("shutdown: %v", err)
+				}
+			case <-time.After(2 * time.Second):
+				t.Fatal("handler defeated shutdown deadline")
+			}
+			// net/http's HTTP/2 streams observe the closed socket asynchronously.
+			await(t, requestContext.Done())
+			await(t, requestDone)
+		})
+	}
+}