test: cover tree live polling resync

rust/crates/mnote-web/src/routes/local_folder_events.rs

@@ -514,4 +514,38 @@ mod tests {
         assert!(payload["data"]["dataset"]["kernelFileTreeProjection"].is_object());
         assert!(payload["data"]["tree"].is_object());
     }
+
+    #[test]
+    fn tree_live_polling_resync_payload_tracks_revision_changes() {
+        let root = test_root("tree-live-polling-resync");
+        std::fs::write(root.join("README.md"), "# Initial\n").expect("write initial");
+        let root_uri = format!("file://{}", root.display());
+        let workspace_id =
+            local_workspace_id_from_root_uri(&root_uri).expect("resolve local workspace id");
+        let initial_revision = local_folder_watch_revision(&root_uri)
+            .expect("initial revision")
+            .revision;
+
+        assert!(
+            tree_live_polling_resync_payload(&root_uri, &workspace_id, &initial_revision).is_none(),
+            "revision 未变化时不应发送 resync"
+        );
+
+        std::fs::create_dir_all(root.join("docs")).expect("create docs");
+        std::fs::write(root.join("docs/new.md"), "# New\n").expect("write new markdown");
+        let (next_revision, payload) =
+            tree_live_polling_resync_payload(&root_uri, &workspace_id, &initial_revision)
+                .expect("revision change should build resync payload");
+
+        assert_ne!(next_revision, initial_revision);
+        assert_eq!(payload["kind"], "resync");
+        assert_eq!(payload["sourceKind"], "local_folder");
+        assert_eq!(payload["rootUri"], root_uri);
+        assert_eq!(payload["workspaceId"], workspace_id);
+        assert_eq!(payload["revision"], next_revision);
+        assert!(payload["data"]["dataset"]["kernel_sidebar_projection"].is_object());
+        assert!(payload["data"]["dataset"]["kernel_file_tree_projection"].is_object());
+
+        let _ = std::fs::remove_dir_all(root);
+    }
 }