test(core): add boundary coverage

src/lib.rs

@@ -1498,6 +1498,43 @@ mod tests {
         assert_eq!(event.token_rate_per_sec, 10.0);
     }
 
+    #[test]
+    fn burn_detector_switches_at_timeout_boundary_and_recovers() {
+        let mut detector = AgentBurnDetector::new(AgentBurnConfig {
+            min_rate_per_sec: 1.0,
+            timeout_secs: 60,
+        });
+        let burning = AgentPulse::from_abtop_status(&json!({
+            "interval_ms": 1000,
+            "token_rate": 10.0,
+            "sessions_total": 1,
+            "sessions_active": 1
+        }));
+        let idle = AgentPulse::from_abtop_status(&json!({
+            "interval_ms": 1000,
+            "token_rate": 0.0,
+            "sessions_total": 1,
+            "sessions_active": 0
+        }));
+
+        assert_eq!(
+            detector.observe(&burning, 100).state,
+            AgentBurnState::Active
+        );
+
+        let before_timeout = detector.observe(&burning, 159);
+        assert_eq!(before_timeout.state, AgentBurnState::Active);
+        assert_eq!(before_timeout.burning_for_secs, Some(59));
+
+        let at_timeout = detector.observe(&burning, 160);
+        assert_eq!(at_timeout.state, AgentBurnState::Runaway);
+        assert_eq!(at_timeout.burning_for_secs, Some(60));
+
+        let recovery = detector.observe(&idle, 161);
+        assert_eq!(recovery.state, AgentBurnState::Recovery);
+        assert_eq!(recovery.burning_for_secs, None);
+    }
+
     #[test]
     fn burn_detector_recovers_when_rate_drops_to_zero() {
         let mut detector = AgentBurnDetector::new(AgentBurnConfig {

src/parse.rs

@@ -404,6 +404,43 @@ mod tests {
         assert_eq!(windows[0].level, "ok");
     }
 
+    #[test]
+    fn window_level_changes_on_threshold_boundaries() {
+        let mut credits = Metric {
+            used: 74.9,
+            limit: 100.0,
+            remaining: 25.1,
+            percent: 74.9,
+        };
+
+        assert_eq!(window_level(Some(&credits), None, 75.0, 90.0), "ok");
+
+        credits.percent = 75.0;
+        assert_eq!(window_level(Some(&credits), None, 75.0, 90.0), "warning");
+
+        credits.percent = 89.9;
+        assert_eq!(window_level(Some(&credits), None, 75.0, 90.0), "warning");
+
+        credits.percent = 90.0;
+        assert_eq!(window_level(Some(&credits), None, 75.0, 90.0), "danger");
+    }
+
+    #[test]
+    fn summarize_metric_clamps_over_limit_percent() {
+        let payload = json!({
+            "usage": {
+                "rows": [{"credits5Hours": 1500, "creditLimit5Hours": 100}]
+            }
+        });
+
+        let windows = summarize_me(&payload, 75.0, 90.0);
+        let credits = windows[0].credits.as_ref().unwrap();
+
+        assert_eq!(credits.remaining, 0.0);
+        assert_eq!(credits.percent, 999.0);
+        assert_eq!(windows[0].level, "danger");
+    }
+
     #[test]
     fn peak_percent_returns_max() {
         let windows = summarize_me(&demo_payload(), 75.0, 90.0);