Fix test failures and thread context warnings

Fixed two issues:
1. test_terminal_sendall_with_container: Changed sock.recv() to sock._sock.recv() to use the correct SocketIO API
2. Thread context warnings: Captured request.sid before starting read_output thread to avoid "Working outside of request context" errors
3. test_input_with_direct_socket_fallback: Updated mock socket to block instead of returning empty immediately, which was causing premature thread cleanup

All 79 tests now pass with no warnings.

https://claude.ai/code/session_01DLxxKWp6dmtGD4ZUQrReTb

backend/app.py

@@ -514,13 +514,16 @@ def handle_start_terminal(data):
             'container_id': container_id
         }
 
+        # Capture request.sid before starting thread to avoid context issues
+        sid = request.sid
+
         # Start a thread to read from the container and send to client
         def read_output():
             sock = exec_instance.output
             try:
                 while True:
                     # Check if socket is still connected
-                    if request.sid not in active_terminals:
+                    if sid not in active_terminals:
                         break
 
                     try:
@@ -536,20 +539,20 @@ def handle_start_terminal(data):
                             decoded_data = data.decode('latin-1', errors='replace')
 
                         socketio.emit('output', {'data': decoded_data},
-                                    namespace='/terminal', room=request.sid)
+                                    namespace='/terminal', room=sid)
                     except Exception as e:
                         logger.error(f"Error reading from container: {e}")
                         break
             finally:
                 # Clean up
-                if request.sid in active_terminals:
-                    del active_terminals[request.sid]
+                if sid in active_terminals:
+                    del active_terminals[sid]
                 try:
                     sock.close()
                 except:
                     pass
                 socketio.emit('exit', {'code': 0},
-                            namespace='/terminal', room=request.sid)
+                            namespace='/terminal', room=sid)
 
         # Start the output reader thread
         output_thread = threading.Thread(target=read_output, daemon=True)

backend/tests/test_websocket_coverage.py

@@ -377,15 +377,24 @@ class TestWebSocketCoverage:
     def test_input_with_direct_socket_fallback(self, mock_get_client, socketio_client, auth_token):
         """Test that input works with direct socket (no _sock attribute)"""
         import app
+        import threading
 
         mock_client = MagicMock()
         mock_container = MagicMock()
         mock_exec_instance = MagicMock()
 
+        # Create an event to control when the socket returns empty
+        stop_event = threading.Event()
+
+        def mock_recv(size):
+            # Block until stop_event is set, then return empty to exit thread
+            stop_event.wait(timeout=1.0)
+            return b''
+
         # Create socket WITHOUT _sock attribute (direct socket)
         mock_socket = MagicMock(spec=['sendall', 'recv', 'close'])
         mock_socket.sendall = MagicMock()
-        mock_socket.recv = MagicMock(return_value=b'')
+        mock_socket.recv = MagicMock(side_effect=mock_recv)
         mock_socket.close = MagicMock()
 
         # Ensure it has NO _sock attribute
@@ -415,3 +424,7 @@ class TestWebSocketCoverage:
 
         # Verify sendall was called on the socket itself (not _sock)
         mock_socket.sendall.assert_called_with(b'echo test\n')
+
+        # Signal the thread to exit and clean up
+        stop_event.set()
+        time.sleep(0.1)

backend/tests/test_websocket_integration.py

@@ -57,7 +57,7 @@ class TestContainerSocketBehavior:
         if not is_simulated:
             # Only test actual output with real Docker
             time.sleep(0.2)
-            output = sock.recv(4096)
+            output = sock._sock.recv(4096)
 
             # Verify we got output without errors
             assert output is not None