Merge pull request #19 from joshorr/josho/fix-dump-as-missing-when-we-have-real-value

Josho/fix dump as missing when we have real value

Author: joshorr

pydantic_partials/meta.py

@@ -95,6 +95,10 @@ def __new__(
                 raise ValueError(f'Invalid/Unknown `partial_auto` config value ({final_partial_auto}), use bool value.')
 
             for k, v in cls.model_fields.items():
+                if k in partial_fields:
+                    # The field is already a Partial
+                    continue
+
                 if v.default is PydanticUndefined and v.default_factory is None:
                     v.annotation = v.annotation | MissingType
                     partial_fields.add(k)

pydantic_partials/partial.py

@@ -32,7 +32,7 @@ class PartialModel(
     """
     Class Args:
 
-    - auto_partial: For more details see `pydantic_partials.config.PartialConfigDict.auto_partials`.
+    - auto_partials: For more details see `pydantic_partials.config.PartialConfigDict.auto_partials`.
         - If `Default`: Inherit behavior from parent/model_config; otherwise defaults to `True`.
         - If `True` (default): Will automatically make all fields on the model `Partial`.
         - If `False`: User needs to mark individual fields as `Partial` where they want.

pydantic_partials/sentinels.py

@@ -28,19 +28,26 @@ def __get_pydantic_core_schema__(
 
     @staticmethod
     def _validate(value: Any, info: core_schema.ValidationInfo) -> 'MissingType':
-        # Tells Pydantic that our Sentinel value 'Missing' is our validated value.
-        # return Missing
+        if value is Missing:
+            # Keeps the associated attribute 'deleted/omitted' from model.
+            raise PydanticOmit()
 
-        # Keeps the associated attribute 'deleted/omitted' from model.
-        #
-        raise PydanticOmit()
+        # `value` is not Missing, return it unchanged.
+        return value
 
     @staticmethod
     def _serialize(value: Any) -> 'MissingType':
         # Keeps the associated attribute 'deleted/omitted' from model.
         # raise PydanticOmit()
-        # return 'a'
-        return Missing
+
+        # Return same value we got, when requested to try and serialize real data it's not 'Missing',
+        # and if it is, that means `Value` is `Missing` and we are fine to return that also.
+        # I would love to rase a `raise PydanticOmit()` if `value` is `Missing`, but that does not currently work
+        # for Pydantic, so I just return the `Missing` unchanged for now.
+        # If there is a serialization error later on about how Pydantic can't turn `Missing` into a `Json`
+        # then we can debug the situation
+        # (right now PartialModel should delete any attributes that are set to `Missing` to work around this limitation)
+        return value
 
 
 Missing = MissingType()