trying to adress issue rte-france#235

.gitignore

@@ -312,7 +312,9 @@ grid2op/data_test/l2rpn_neurips_2020_track1_with_alert.zip
 issue_208_res/
 test_issue_208.py
 test_issue_220.py
-test_issue_*.py
+test_issue235.py
+test_issue*.py
+!grid2op/tests/test_issue*.py
 res_alert/
 env_debug_time_last_alarm_inconsistency.zip
 env_debug_time_last_alarm_inconsistency/

grid2op/Observation/_ObsEnv.py

@@ -457,8 +457,9 @@ def get_obs(self, _update_state=False):
         res: :class:`grid2op.Observation.Observation`
             The observation available.
         """
-        self.current_obs.update(self, with_forecast=False)
-        res = copy.deepcopy(self.current_obs)
+        if _update_state:
+            self.current_obs.update(self, with_forecast=False)
+        res = self.current_obs.copy()
         return res
 
     def update_grid(self, env):

grid2op/tests/test_issue_235.py

@@ -0,0 +1,53 @@
+# Copyright (c) 2019-2020, RTE (https://www.rte-france.com)
+# See AUTHORS.txt
+# This Source Code Form is subject to the terms of the Mozilla Public License, version 2.0.
+# If a copy of the Mozilla Public License, version 2.0 was not distributed with this file,
+# you can obtain one at http://mozilla.org/MPL/2.0/.
+# SPDX-License-Identifier: MPL-2.0
+# This file is part of Grid2Op, Grid2Op a testbed platform to model sequential decision making in power systems.
+
+import warnings
+
+import grid2op
+from grid2op.Chronics import ChangeNothing
+from grid2op.tests.helper_path_test import *
+from grid2op.Observation import CompleteObservation
+
+
+class Issue224TesterObs(CompleteObservation):
+    def __init__(self, obs_env=None, action_helper=None, seed=None):
+        CompleteObservation.__init__(self, obs_env, action_helper, seed)
+        self._is_updated = False
+
+    def update(self, env, with_forecast=True):
+        self._is_updated = True
+        super().update(env, with_forecast)
+
+
+class Issue224Tester(unittest.TestCase):
+    """
+    This bug was due to the environment that updated the observation even when it diverges.
+
+    In this test i checked that the `update` method of the observation is not called even when I simulate
+    an action that lead to divergence of the powerflow.
+    """
+    def setUp(self) -> None:
+        with warnings.catch_warnings():
+            warnings.filterwarnings("ignore")
+            env_nm = 'l2rpn_icaps_2021'
+            # from lightsim2grid import LightSimBackend
+            # backend=LightSimBackend(),
+            self.env = grid2op.make(env_nm, test=True, observation_class=Issue224TesterObs)
+            self.env.seed(0)
+            self.env.reset()
+
+    def test_diverging_action(self):
+        final_dict = {'generators_id': [(19, 1)],
+                      'loads_id': [(30, 2)],
+                      'lines_or_id': [(58, 1)],
+                      'lines_ex_id': [(46, 1), (47, 2)]}
+        action = self.env.action_space({"set_bus": final_dict})
+        obs = self.env.reset()
+        simobs, simr, simd, siminfo = obs.simulate(action, time_step=0)
+        assert np.all(simobs.gen_p == 0.)
+        assert not simobs._is_updated