наблюдаемость: ввести безопасный контракт метрик

crates/crank-community-mcp/tests/session_metrics.rs

@@ -0,0 +1,76 @@
+use std::{sync::Arc, time::Duration};
+
+use crank_community_mcp::session::{
+    ActiveSessionMetrics, InMemorySessionStore, SharedSessionStore, TransportSessionStore,
+    spawn_session_cleanup,
+};
+use metrics_util::debugging::{DebugValue, DebuggingRecorder, Snapshotter};
+use time::OffsetDateTime;
+
+#[tokio::test]
+async fn active_session_sampler_tracks_create_delete_and_expiry() {
+    let recorder = DebuggingRecorder::new();
+    let snapshotter = recorder.snapshotter();
+    recorder
+        .install()
+        .expect("isolated integration test recorder");
+
+    let store = Arc::new(InMemorySessionStore::default());
+    let sessions: SharedSessionStore = store.clone();
+    let sampler = ActiveSessionMetrics::start(Arc::clone(&sessions));
+    assert_gauge(&sampler, &snapshotter, 0.0).await;
+
+    let now = OffsetDateTime::now_utc();
+    store
+        .create(
+            "2025-11-25",
+            "default",
+            "agent",
+            false,
+            now,
+            Some(now + time::Duration::milliseconds(100)),
+        )
+        .await
+        .unwrap();
+    assert_gauge(&sampler, &snapshotter, 1.0).await;
+
+    spawn_session_cleanup(sessions, sampler, Duration::from_millis(10));
+    assert_gauge_without_refresh(&snapshotter, 0.0).await;
+}
+
+async fn assert_gauge_without_refresh(snapshotter: &Snapshotter, expected: f64) {
+    for _ in 0..100 {
+        tokio::time::sleep(Duration::from_millis(10)).await;
+        if gauge_value(snapshotter) == Some(expected) {
+            return;
+        }
+    }
+    panic!("active session gauge did not become {expected} through cleanup");
+}
+
+async fn assert_gauge(sampler: &ActiveSessionMetrics, snapshotter: &Snapshotter, expected: f64) {
+    for _ in 0..50 {
+        sampler.refresh();
+        tokio::time::sleep(Duration::from_millis(10)).await;
+        if gauge_value(snapshotter) == Some(expected) {
+            return;
+        }
+    }
+    panic!("active session gauge did not become {expected}");
+}
+
+fn gauge_value(snapshotter: &Snapshotter) -> Option<f64> {
+    snapshotter
+        .snapshot()
+        .into_vec()
+        .into_iter()
+        .find_map(|(key, _, _, value)| {
+            if key.key().name() != "crank_mcp_active_sessions" {
+                return None;
+            }
+            match value {
+                DebugValue::Gauge(value) => Some(value.into_inner()),
+                _ => None,
+            }
+        })
+}