Address comments.

smarts/core/provider.py

@@ -19,14 +19,16 @@
 # THE SOFTWARE.
 from dataclasses import dataclass, field
 from enum import IntFlag
-from typing import List, Optional, Set
+from typing import List, Optional, Set, Tuple
 
 from .controllers import ActionSpaceType
 from .scenario import Scenario
 from .vehicle import VehicleState
 
 
 class ProviderRecoveryFlags(IntFlag):
+    """This describes actions to be taken with a provider should it fail."""
+
     NOT_REQUIRED = 0x00000000
     """Not needed for the current step. Error causes skip."""
     EPISODE_REQUIRED = 0x00000010
@@ -91,7 +93,7 @@ def teardown(self):
 
     def recover(
         self, scenario, elapsed_sim_time: float, error: Optional[Exception] = None
-    ) -> bool:
+    ) -> Tuple[ProviderState, bool]:
         """Attempt to reconnect the provider if an error or disconnection occured.
         Implementations may choose to e-raise the passed in exception.
         Args:
@@ -103,7 +105,7 @@ def recover(
         """
         if error:
             raise error
-        return False
+        return ProviderState(), False
 
     @property
     def connected(self) -> bool:

smarts/core/smarts.py

@@ -66,7 +66,7 @@
 logging.basicConfig(
     format="%(asctime)s.%(msecs)03d %(levelname)s: {%(module)s} %(message)s",
     datefmt="%Y-%m-%d,%H:%M:%S",
-    level=logging.INFO,
+    level=logging.ERROR,
 )
 
 MAX_PYBULLET_FREQ = 240
@@ -415,8 +415,7 @@ def add_provider(
         recovery_flags: ProviderRecoveryFlags = ProviderRecoveryFlags.EXPERIMENT_REQUIRED,
     ):
         assert isinstance(provider, Provider)
-        self._providers.append(provider)
-        self._provider_recovery_flags[provider] = recovery_flags
+        self._insert_provider(len(self._providers), provider, recovery_flags)
 
     def _insert_provider(
         self,
@@ -850,8 +849,7 @@ def _setup_providers(self, scenario) -> ProviderState:
             try:
                 new_provider_state = provider.setup(scenario)
             except Exception as provider_error:
-                self._handle_provider(provider, provider_error)
-                new_provider_state = ProviderState()
+                new_provider_state = self._handle_provider(provider, provider_error)
             provider_state.merge(new_provider_state)
         return provider_state
 
@@ -877,7 +875,7 @@ def _reset_providers(self):
             except Exception as provider_error:
                 self._handle_provider(provider, provider_error)
 
-    def _handle_provider(self, provider: Provider, provider_error):
+    def _handle_provider(self, provider: Provider, provider_error) -> ProviderState:
         provider_problem = bool(provider_error or not provider.connected)
         if not provider_problem:
             return
@@ -887,12 +885,13 @@ def _handle_provider(self, provider: Provider, provider_error):
         )
         recovered = False
         if recovery_flags & ProviderRecoveryFlags.ATTEMPT_RECOVERY:
-            recovered = provider.recover(
+            provider_state, recovered = provider.recover(
                 self._scenario, self.elapsed_sim_time, provider_error
             )
 
+        provider_state = provider_state or ProviderState()
         if recovered:
-            return
+            return provider_state
 
         if recovery_flags & ProviderRecoveryFlags.EPISODE_REQUIRED:
             self._reset_required = True
@@ -901,7 +900,7 @@ def _handle_provider(self, provider: Provider, provider_error):
                     f"`Provider {provider.__class__.__name__} has crashed during reset`"
                 )
                 raise provider_error
-            return
+            return provider_state
         elif recovery_flags & ProviderRecoveryFlags.EXPERIMENT_REQUIRED:
             raise provider_error
 
@@ -961,8 +960,7 @@ def matches_no_provider_action_space(agent_id):
             try:
                 provider_state = self._step_provider(provider, actions)
             except Exception as provider_error:
-                self._handle_provider(provider, provider_error)
-                provider_state = ProviderState()
+                provider_state = self._handle_provider(provider, provider_error)
 
             if provider == self._traffic_sim:
                 # Remove agent vehicles from provider vehicles

smarts/core/sumo_traffic_simulation.py

@@ -369,7 +369,7 @@ def recover(
             self._handle_traci_disconnect(error)
         elif isinstance(error, Exception):
             raise error
-        return False
+        return ProviderState(), False
 
     def step(self, provider_actions, dt, elapsed_sim_time) -> ProviderState:
         """