pyright

python_modules/dagster/dagster/_config/pythonic_config/conversion_utils.py

@@ -268,6 +268,7 @@ class OpConfigWithUnion(Config):
     from .config import Config, infer_schema_from_config_class
 
     field_type = pydantic_field.annotation
+    discriminator = pydantic_field.discriminator if pydantic_field.discriminator else None
 
     if not get_origin(field_type) == Union:
         raise DagsterInvalidDefinitionError("Discriminated union must be a Union type.")
@@ -277,21 +278,21 @@ class OpConfigWithUnion(Config):
         raise NotImplementedError("Discriminated unions with non-Config types are not supported.")
 
     sub_fields_mapping = {}
-    for sub_field in sub_fields:
-        sub_field_annotation = model_fields(sub_field)[pydantic_field.discriminator].annotation
+    if discriminator:
+        for sub_field in sub_fields:
+            sub_field_annotation = model_fields(sub_field)[discriminator].annotation
+
+            for sub_field_key in get_args(sub_field_annotation):
+                sub_fields_mapping[sub_field_key] = sub_field
 
-        for sub_field_key in get_args(sub_field_annotation):
-            sub_fields_mapping[sub_field_key] = sub_field
     # First, we generate a mapping between the various discriminator values and the
     # Dagster config fields that correspond to them. We strip the discriminator key
     # from the fields, since the user should not have to specify it.
 
     dagster_config_field_mapping = {
         discriminator_value: infer_schema_from_config_class(
             field,
-            fields_to_omit=(
-                {pydantic_field.discriminator} if pydantic_field.discriminator else None
-            ),
+            fields_to_omit=({discriminator} if discriminator else None),
         )
         for discriminator_value, field in sub_fields_mapping.items()
     }

python_modules/dagster/dagster/_config/pythonic_config/pydantic_compat_layer.py

@@ -1,4 +1,5 @@
 from typing import (
+    TYPE_CHECKING,
     Any,
     Dict,
     List,
@@ -13,6 +14,9 @@
     IAttachDifferentObjectToOpContext as IAttachDifferentObjectToOpContext,
 )
 
+if TYPE_CHECKING:
+    from pydantic.fields import ModelField
+
 USING_PYDANTIC_2 = int(pydantic.__version__.split(".")[0]) >= 2
 
 
@@ -21,8 +25,8 @@ class ModelFieldCompat:
     metadata and annotations between Pydantic 1 and 2.
     """
 
-    def __init__(self, field):
-        self.field = field
+    def __init__(self, field) -> None:
+        self.field: "ModelField" = field
 
     @property
     def annotation(self) -> Type:
@@ -50,16 +54,16 @@ def description(self) -> Optional[str]:
 
     def is_required(self) -> bool:
         if USING_PYDANTIC_2:
-            if hasattr(self.field, "is_required"):
-                return self.field.is_required()
+            return self.field.is_required()  # type: ignore
         else:
-            return self.field.required
+            # required is of type 'BoolUndefined', which is a Union of bool and pydantic 1.x's UndefinedType
+            return self.field.required if isinstance(self.field.required, bool) else False
 
     @property
     def discriminator(self) -> Optional[str]:
         if USING_PYDANTIC_2:
             if hasattr(self.field, "discriminator"):
-                return self.field.discriminator if hasattr(self.field, "discriminator") else None
+                return self.field.discriminator if hasattr(self.field, "discriminator") else None  # type: ignore
         else:
             return getattr(self.field, "discriminator_key", None)