Fix mypy issues

baybe/campaign.py

@@ -12,6 +12,7 @@
 from attrs.converters import optional
 from attrs.validators import instance_of
 
+from baybe.exceptions import IncompatibilityError
 from baybe.objectives.base import Objective, to_objective
 from baybe.parameters.base import Parameter
 from baybe.recommenders.base import RecommenderProtocol
@@ -24,7 +25,7 @@
     validate_searchspace_from_config,
 )
 from baybe.serialization import SerialMixin, converter
-from baybe.surrogates.base import Surrogate
+from baybe.surrogates.base import SurrogateProtocol
 from baybe.targets.base import Target
 from baybe.telemetry import (
     TELEM_LABELS,
@@ -278,14 +279,23 @@ def posterior(self, candidates: pd.DataFrame) -> Posterior:
             candidates: The candidate points in experimental recommendations.
                 For details, see :meth:`baybe.surrogates.base.Surrogate.posterior`.
 
+        Raises:
+            IncompatibilityError: If the underlying surrogate model exposes no
+                method for computing the posterior distribution.
+
         Returns:
             Posterior: The corresponding posterior object.
             For details, see :meth:`baybe.surrogates.base.Surrogate.posterior`.
         """
         surrogate = self.get_surrogate()
+        if not hasattr(surrogate, method_name := "posterior"):
+            raise IncompatibilityError(
+                f"The used surrogate type '{surrogate.__class__.__name__}' does not "
+                f"provide a '{method_name}' method."
+            )
         return surrogate.posterior(candidates)
 
-    def get_surrogate(self) -> Surrogate:
+    def get_surrogate(self) -> SurrogateProtocol:
         """Get the current surrogate model.
 
         Raises:
@@ -294,6 +304,12 @@ def get_surrogate(self) -> Surrogate:
         Returns:
             Surrogate: The surrogate of the current recommender.
         """
+        if self.objective is None:
+            raise IncompatibilityError(
+                f"No surrogate is available since no '{Objective.__name__}' is defined."
+            )
+
+        pure_recommender: RecommenderProtocol
         if isinstance(self.recommender, MetaRecommender):
             pure_recommender = self.recommender.get_current_recommender()
         else:

baybe/exceptions.py

@@ -10,6 +10,19 @@ class UnusedObjectWarning(UserWarning):
 
 
 ##### Exceptions #####
+
+
+class IncompatibilityError(Exception):
+    """Incompatible components are used together."""
+
+
+class IncompatibleSearchSpaceError(IncompatibilityError):
+    """
+    A recommender is used with a search space that contains incompatible parts,
+    e.g. a discrete recommender is used with a hybrid or continuous search space.
+    """
+
+
 class NotEnoughPointsLeftError(Exception):
     """
     More recommendations are requested than there are viable parameter configurations
@@ -24,13 +37,6 @@ class NoMCAcquisitionFunctionError(Exception):
     """
 
 
-class IncompatibleSearchSpaceError(Exception):
-    """
-    A recommender is used with a search space that contains incompatible parts,
-    e.g. a discrete recommender is used with a hybrid or continuous search space.
-    """
-
-
 class EmptySearchSpaceError(Exception):
     """The created search space contains no parameters."""
 

baybe/surrogates/base.py

@@ -64,6 +64,9 @@ class _NoTransform(Enum):
 class SurrogateProtocol(Protocol):
     """Type protocol specifying the interface surrogate models need to implement."""
 
+    # TODO: Final layout still to be optimized. For example, shall we require a
+    #   `posterior` method?
+
     def fit(
         self,
         searchspace: SearchSpace,

mypy.ini

@@ -21,7 +21,7 @@ ignore_missing_imports = True
 [mypy-gpytorch.*]
 ignore_missing_imports = True
 
-[mypy-joblib]
+[mypy-joblib.*]
 ignore_missing_imports = True
 
 [mypy-mordred]