fix(coding_agent): add context managers and narrow exception handling

Author: Sudhendra

contributing/samples/coding_agent/agent.py

@@ -49,6 +49,7 @@
 import binascii
 from datetime import datetime
 import os
+import socket
 import urllib.error
 import urllib.request
 
@@ -127,19 +128,19 @@ def fetch_url(url: str) -> dict:
                 "url": url,
                 "success": True,
             }
-    except urllib.error.URLError as e:
+    except (urllib.error.URLError, socket.timeout) as e:
         return {
             "content": "",
             "url": url,
             "success": False,
             "error": f"Failed to fetch URL: {str(e)}",
         }
-    except Exception as e:
+    except OSError as e:
         return {
             "content": "",
             "url": url,
             "success": False,
-            "error": f"Unexpected error: {str(e)}",
+            "error": f"Failed to decode response: {str(e)}",
         }
 
 
@@ -256,11 +257,6 @@ def save_chart(image_data: str, filename: str) -> dict:
             "success": False,
             "error": f"Failed to save file: {str(e)}",
         }
-    except Exception as e:
-        return {
-            "success": False,
-            "error": f"Unexpected error: {str(e)}",
-        }
 
 
 def list_saved_charts() -> dict:
@@ -293,7 +289,7 @@ def list_saved_charts() -> dict:
             "directory": HOST_CHARTS_DIR,
             "count": len(charts),
         }
-    except Exception as e:
+    except OSError as e:
         return {
             "success": False,
             "error": f"Failed to list charts: {str(e)}",

src/google/adk/agents/coding_agent.py

@@ -650,9 +650,11 @@ def cleanup(self) -> None:
             self._coding_executor = None
         self._resolved_tools = None
 
-    def __del__(self):
-        """Destructor to clean up resources."""
-        try:
-            self.cleanup()
-        except Exception:
-            pass
+    def __enter__(self) -> "CodingAgent":
+        """Enter context manager and return self."""
+        return self
+
+    def __exit__(self, exc_type, exc, traceback) -> bool:
+        """Exit context manager and clean up resources."""
+        self.cleanup()
+        return False

src/google/adk/code_executors/coding_agent_code_executor.py

@@ -505,6 +505,11 @@ def cleanup(self) -> None:
     self._stop_tool_server()
     self._execution_history.clear()
 
-  def __del__(self):
-    """Destructor to clean up resources."""
+  def __enter__(self) -> CodingAgentCodeExecutor:
+    """Enter context manager and return self."""
+    return self
+
+  def __exit__(self, exc_type, exc, traceback) -> bool:
+    """Exit context manager and clean up resources."""
     self.cleanup()
+    return False