[BUGFIX] argilla: prevent enum literal validation errors (#5679)

# Description
<!-- Please include a summary of the changes and the related issue.
Please also include relevant motivation and context. List any
dependencies that are required for this change. -->

In some environments, working with enun instances as string values may
lead to some validation errors. See [this discord
discussion](https://discord.com/channels/879548962464493619/1300936213531983882/1300936213531983882).

This PR reviews how metadata settings classes are defined, and defines
type directly as a literal string, in the same way we do fo questions or
fields, instead of using the MetadataPropertyType class.

**Type of change**
<!-- Please delete options that are not relevant. Remember to title the
PR according to the type of change -->

- Bug fix (non-breaking change which fixes an issue)
- Refactor (change restructuring the codebase without changing
functionality)

**How Has This Been Tested**
<!-- Please add some reference about how your feature has been tested.
-->

**Checklist**
<!-- Please go over the list and make sure you've taken everything into
account -->

- I added relevant documentation
- I followed the style guidelines of this project
- I did a self-review of my code
- I made corresponding changes to the documentation
- I confirm My changes generate no new warnings
- I have added tests that prove my fix is effective or that my feature
works
- I have added relevant notes to the CHANGELOG.md file (See
https://keepachangelog.com/)

argilla/src/argilla/_models/__init__.py

@@ -50,7 +50,6 @@
 )
 from argilla._models._settings._metadata import (
     MetadataFieldModel,
-    MetadataPropertyType,
     BaseMetadataPropertySettings,
     TermsMetadataPropertySettings,
     NumericMetadataPropertySettings,

argilla/src/argilla/_models/_settings/_metadata.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from enum import Enum
 from typing import List, Literal, Optional, Union, Annotated, Any
 from uuid import UUID
 
@@ -22,19 +21,12 @@
 from argilla._models import ResourceModel
 
 
-class MetadataPropertyType(str, Enum):
-    terms = "terms"
-    integer = "integer"
-    float = "float"
-
-
 class BaseMetadataPropertySettings(BaseModel):
-    type: MetadataPropertyType
     visible_for_annotators: Optional[bool] = True
 
 
 class TermsMetadataPropertySettings(BaseMetadataPropertySettings):
-    type: Literal[MetadataPropertyType.terms]
+    type: Literal["terms"] = "terms"
     values: Optional[List[Any]] = None
 
     @field_validator("values")
@@ -64,7 +56,7 @@ def __validate_min_max(cls, values):
 
 
 class IntegerMetadataPropertySettings(NumericMetadataPropertySettings):
-    type: Literal[MetadataPropertyType.integer]
+    type: Literal["integer"] = "integer"
 
     @model_validator(mode="before")
     @classmethod
@@ -78,7 +70,7 @@ def __validate_min_max(cls, values):
 
 
 class FloatMetadataPropertySettings(NumericMetadataPropertySettings):
-    type: Literal[MetadataPropertyType.float]
+    type: Literal["float"] = "float"
 
 
 MetadataPropertySettings = Annotated[
@@ -97,12 +89,15 @@ class MetadataFieldModel(ResourceModel):
     name: str
     settings: MetadataPropertySettings
 
-    type: Optional[MetadataPropertyType] = Field(None, validate_default=True)
     title: Optional[str] = None
     visible_for_annotators: Optional[bool] = True
 
     dataset_id: Optional[UUID] = None
 
+    @property
+    def type(self) -> str:
+        return self.settings.type
+
     @field_validator("title")
     @classmethod
     def __title_default(cls, title, values):
@@ -112,10 +107,3 @@ def __title_default(cls, title, values):
     @field_serializer("id", "dataset_id", when_used="unless-none")
     def serialize_id(self, value: UUID) -> str:
         return str(value)
-
-    @field_validator("type", mode="plain")
-    @classmethod
-    def __validate_type(cls, type, values):
-        if type is None:
-            return values.data["settings"].type
-        return type

argilla/src/argilla/settings/_metadata.py

@@ -17,7 +17,6 @@
 from argilla._api._metadata import MetadataAPI
 from argilla._exceptions import MetadataError
 from argilla._models import (
-    MetadataPropertyType,
     TermsMetadataPropertySettings,
     FloatMetadataPropertySettings,
     IntegerMetadataPropertySettings,
@@ -122,13 +121,12 @@ def __init__(
         super().__init__(client=client)
 
         try:
-            settings = TermsMetadataPropertySettings(values=options, type=MetadataPropertyType.terms)
+            settings = TermsMetadataPropertySettings(values=options)
         except ValueError as e:
             raise MetadataError(f"Error defining metadata settings for {name}") from e
 
         self._model = MetadataFieldModel(
             name=name,
-            type=MetadataPropertyType.terms,
             title=title,
             settings=settings,
             visible_for_annotators=visible_for_annotators,
@@ -176,13 +174,12 @@ def __init__(
         super().__init__(client=client)
 
         try:
-            settings = FloatMetadataPropertySettings(min=min, max=max, type=MetadataPropertyType.float)
+            settings = FloatMetadataPropertySettings(min=min, max=max)
         except ValueError as e:
             raise MetadataError(f"Error defining metadata settings for {name}") from e
 
         self._model = MetadataFieldModel(
             name=name,
-            type=MetadataPropertyType.float,
             title=title,
             settings=settings,
             visible_for_annotators=visible_for_annotators,
@@ -237,13 +234,12 @@ def __init__(
         super().__init__(client=client)
 
         try:
-            settings = IntegerMetadataPropertySettings(min=min, max=max, type=MetadataPropertyType.integer)
+            settings = IntegerMetadataPropertySettings(min=min, max=max)
         except ValueError as e:
             raise MetadataError(f"Error defining metadata settings for {name}") from e
 
         self._model = MetadataFieldModel(
             name=name,
-            type=MetadataPropertyType.integer,
             title=title,
             settings=settings,
             visible_for_annotators=visible_for_annotators,
@@ -283,27 +279,14 @@ def from_model(cls, model: MetadataFieldModel) -> "IntegerMetadataProperty":
 class MetadataField:
     @classmethod
     def from_model(cls, model: MetadataFieldModel) -> MetadataType:
-        switch = {
-            MetadataPropertyType.terms: TermsMetadataProperty,
-            MetadataPropertyType.float: FloatMetadataProperty,
-            MetadataPropertyType.integer: IntegerMetadataProperty,
-        }
-        metadata_type = model.type
-        try:
-            return switch[metadata_type].from_model(model)
-        except KeyError as e:
-            raise MetadataError(f"Unknown metadata property type: {metadata_type}") from e
+        if model.type == "terms":
+            return TermsMetadataProperty.from_model(model)
+        elif model.type == "float":
+            return FloatMetadataProperty.from_model(model)
+        elif model.type == "integer":
+            return IntegerMetadataProperty.from_model(model)
+        raise MetadataError(f"Unknown metadata property type: {model.type}")
 
     @classmethod
     def from_dict(cls, data: dict) -> MetadataType:
-        switch = {
-            MetadataPropertyType.terms: TermsMetadataProperty,
-            MetadataPropertyType.float: FloatMetadataProperty,
-            MetadataPropertyType.integer: IntegerMetadataProperty,
-        }
-        metadata_type = data["type"]
-        try:
-            metadata_model = MetadataFieldModel(**data)
-            return switch[metadata_type].from_model(metadata_model)
-        except KeyError as e:
-            raise MetadataError(f"Unknown metadata property type: {metadata_type}") from e
+        return cls.from_model(MetadataFieldModel(**data))

argilla/tests/unit/test_settings/test_metadata.py

@@ -37,7 +37,6 @@ def test_create_metadata_terms(self, options: list):
             "name": "metadata",
             "settings": {"type": "terms", "values": options, "visible_for_annotators": True},
             "title": "A metadata property",
-            "type": "terms",
             "visible_for_annotators": True,
             "inserted_at": None,
             "updated_at": None,
@@ -59,7 +58,6 @@ def test_create_terms_metadata_without_options(self):
             "name": "metadata",
             "title": "metadata",
             "settings": {"type": "terms", "values": None, "visible_for_annotators": True},
-            "type": "terms",
             "visible_for_annotators": True,
             "inserted_at": None,
             "updated_at": None,