Fix: Check for existing files before saving recording events

When saving events to numbered JSON files, check if the file already
exists and increment the counter until an unused filename is found.
This handles cases where files already exist from previous recordings
in the same directory.

Co-authored-by: openhands <[email protected]>

Author: openhands-agent

openhands-tools/openhands/tools/browser_use/server.py

@@ -224,6 +224,10 @@ async def _inject_scripts_to_session(self) -> None:
     def _save_events_to_file(self, events: list[dict]) -> str | None:
         """Save events to a numbered JSON file.
         
+        Finds the next available filename by incrementing the counter until
+        an unused filename is found. This handles cases where files already
+        exist from previous recordings.
+        
         Args:
             events: List of rrweb events to save.
             
@@ -237,9 +241,14 @@ def _save_events_to_file(self, events: list[dict]) -> str | None:
             return None
 
         os.makedirs(self._recording_save_dir, exist_ok=True)
-        self._recording_file_counter += 1
-        filename = f"{self._recording_file_counter}.json"
-        filepath = os.path.join(self._recording_save_dir, filename)
+        
+        # Find the next available filename
+        while True:
+            self._recording_file_counter += 1
+            filename = f"{self._recording_file_counter}.json"
+            filepath = os.path.join(self._recording_save_dir, filename)
+            if not os.path.exists(filepath):
+                break
 
         with open(filepath, "w") as f:
             json.dump(events, f)