test: unit tests for the sub agent spawning system

src/supervisor/mailbox.rs

@@ -58,3 +58,122 @@ impl Clone for Inbox {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::Utc;
+
+    fn text_envelope(from: &str, to: &str, content: &str) -> Envelope {
+        Envelope {
+            from: from.to_string(),
+            to: to.to_string(),
+            payload: EnvelopePayload::Text {
+                content: content.to_string(),
+            },
+            timestamp: Utc::now(),
+        }
+    }
+
+    fn task_completed_envelope(from: &str, to: &str) -> Envelope {
+        Envelope {
+            from: from.to_string(),
+            to: to.to_string(),
+            payload: EnvelopePayload::TaskCompleted {
+                task_id: "t1".into(),
+                summary: "done".into(),
+            },
+            timestamp: Utc::now(),
+        }
+    }
+
+    fn shutdown_request_envelope(from: &str, to: &str) -> Envelope {
+        Envelope {
+            from: from.to_string(),
+            to: to.to_string(),
+            payload: EnvelopePayload::ShutdownRequest {
+                reason: "all done".into(),
+            },
+            timestamp: Utc::now(),
+        }
+    }
+
+    #[test]
+    fn inbox_new_is_empty() {
+        let inbox = Inbox::new();
+        assert!(inbox.drain().is_empty());
+    }
+
+    #[test]
+    fn inbox_default_is_empty() {
+        let inbox = Inbox::default();
+        assert!(inbox.drain().is_empty());
+    }
+
+    #[test]
+    fn deliver_and_drain() {
+        let inbox = Inbox::new();
+        inbox.deliver(text_envelope("a", "b", "hello"));
+        let msgs = inbox.drain();
+        assert_eq!(msgs.len(), 1);
+        assert_eq!(msgs[0].from, "a");
+    }
+
+    #[test]
+    fn drain_empties_inbox() {
+        let inbox = Inbox::new();
+        inbox.deliver(text_envelope("a", "b", "hello"));
+        inbox.drain();
+        assert!(inbox.drain().is_empty());
+    }
+
+    #[test]
+    fn drain_orders_shutdown_before_task_before_text() {
+        let inbox = Inbox::new();
+        inbox.deliver(text_envelope("a", "b", "msg"));
+        inbox.deliver(task_completed_envelope("a", "b"));
+        inbox.deliver(shutdown_request_envelope("a", "b"));
+
+        let msgs = inbox.drain();
+        assert_eq!(msgs.len(), 3);
+        assert!(matches!(
+            msgs[0].payload,
+            EnvelopePayload::ShutdownRequest { .. }
+        ));
+        assert!(matches!(
+            msgs[1].payload,
+            EnvelopePayload::TaskCompleted { .. }
+        ));
+        assert!(matches!(msgs[2].payload, EnvelopePayload::Text { .. }));
+    }
+
+    #[test]
+    fn clone_preserves_messages() {
+        let inbox = Inbox::new();
+        inbox.deliver(text_envelope("a", "b", "hello"));
+        let cloned = inbox.clone();
+        let msgs = cloned.drain();
+        assert_eq!(msgs.len(), 1);
+    }
+
+    #[test]
+    fn clone_is_independent() {
+        let inbox = Inbox::new();
+        inbox.deliver(text_envelope("a", "b", "hello"));
+        let cloned = inbox.clone();
+        inbox.deliver(text_envelope("a", "b", "second"));
+        let original_msgs = inbox.drain();
+        let cloned_msgs = cloned.drain();
+        assert_eq!(original_msgs.len(), 2);
+        assert_eq!(cloned_msgs.len(), 1);
+    }
+
+    #[test]
+    fn multiple_deliveries() {
+        let inbox = Inbox::new();
+        for i in 0..5 {
+            inbox.deliver(text_envelope("a", "b", &format!("msg {i}")));
+        }
+        assert_eq!(inbox.drain().len(), 5);
+    }
+}