Pydantic Fixes and Tests (#311)

* Added SubscriptableBaseModel to the Model classes and added Image codec test

---------

Co-authored-by: Parth Sareen <parth@Parths-MacBook-Pro.local>

ollama/_types.py

@@ -97,6 +97,7 @@ class BaseGenerateRequest(BaseStreamableRequest):
 class Image(BaseModel):
   value: Union[FilePath, Base64Str, bytes]
 
+  # This overloads the `model_dump` method and returns values depending on the type of the `value` field
   @model_serializer
   def serialize_model(self):
     if isinstance(self.value, Path):
@@ -333,7 +334,7 @@ class ModelDetails(SubscriptableBaseModel):
 
 
 class ListResponse(SubscriptableBaseModel):
-  class Model(BaseModel):
+  class Model(SubscriptableBaseModel):
     modified_at: Optional[datetime] = None
     digest: Optional[str] = None
     size: Optional[ByteSize] = None
@@ -394,7 +395,7 @@ class ShowResponse(SubscriptableBaseModel):
 
 
 class ProcessResponse(SubscriptableBaseModel):
-  class Model(BaseModel):
+  class Model(SubscriptableBaseModel):
     model: Optional[str] = None
     name: Optional[str] = None
     digest: Optional[str] = None

tests/test_type_serialization.py

@@ -0,0 +1,15 @@
+from base64 import b64decode, b64encode
+
+from ollama._types import Image
+
+
+def test_image_serialization():
+  # Test bytes serialization
+  image_bytes = b'test image bytes'
+  img = Image(value=image_bytes)
+  assert img.model_dump() == b64encode(image_bytes).decode()
+
+  # Test base64 string serialization
+  b64_str = 'dGVzdCBiYXNlNjQgc3RyaW5n'
+  img = Image(value=b64_str)
+  assert img.model_dump() == b64decode(b64_str).decode()