fix: coerce numeric nutrition values to strings in Cookbook model (fixes #708)

Agent-Logs-Url: https://github.com/dylanlangston/nextcloud-mcp-server/sessions/d7163bb6-ad5d-4406-8d11-145c5317ec19

Co-authored-by: dylanlangston <16236219+dylanlangston@users.noreply.github.com>

nextcloud_mcp_server/models/cookbook.py

@@ -2,7 +2,7 @@
 
 from typing import List, Optional, Union
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 from .base import BaseResponse, IdResponse, StatusResponse
 
@@ -40,6 +40,33 @@ class Nutrition(BaseModel):
 
     model_config = ConfigDict(populate_by_name=True)
 
+    @field_validator(
+        "calories",
+        "carbohydrateContent",
+        "cholesterolContent",
+        "fatContent",
+        "fiberContent",
+        "proteinContent",
+        "saturatedFatContent",
+        "servingSize",
+        "sodiumContent",
+        "sugarContent",
+        "transFatContent",
+        "unsaturatedFatContent",
+        mode="before",
+    )
+    @classmethod
+    def coerce_to_str(cls, v: object) -> object:
+        """Coerce numeric values to strings.
+
+        The schema.org/NutritionInformation spec allows values as either
+        strings (e.g. '650 kcal') or numbers (e.g. 650). Nextcloud Cookbook
+        stores whatever the source provided.
+        """
+        if isinstance(v, (int, float)):
+            return str(v)
+        return v
+
 
 class RecipeStub(BaseModel):
     """Stub of a recipe with basic information."""

tests/unit/test_nutrition_model.py

@@ -0,0 +1,77 @@
+"""Unit tests for Nutrition model numeric coercion (issue #708)."""
+
+import pytest
+
+from nextcloud_mcp_server.models.cookbook import Nutrition
+
+
+@pytest.mark.unit
+def test_nutrition_calories_accepts_string():
+    """String calories values should be accepted as-is."""
+    n = Nutrition(calories="650 kcal")
+    assert n.calories == "650 kcal"
+
+
+@pytest.mark.unit
+def test_nutrition_calories_coerces_int():
+    """Integer calories values should be coerced to strings."""
+    n = Nutrition(calories=260)
+    assert n.calories == "260"
+
+
+@pytest.mark.unit
+def test_nutrition_calories_coerces_float():
+    """Float calories values should be coerced to strings."""
+    n = Nutrition(calories=260.5)
+    assert n.calories == "260.5"
+
+
+@pytest.mark.unit
+def test_nutrition_calories_accepts_none():
+    """None calories should remain None."""
+    n = Nutrition(calories=None)
+    assert n.calories is None
+
+
+@pytest.mark.unit
+def test_nutrition_all_fields_coerce_int():
+    """All nutrition content fields should coerce integer values to strings."""
+    n = Nutrition(
+        calories=260,
+        carbohydrateContent=30,
+        cholesterolContent=10,
+        fatContent=15,
+        fiberContent=5,
+        proteinContent=20,
+        saturatedFatContent=3,
+        servingSize=1,
+        sodiumContent=500,
+        sugarContent=8,
+        transFatContent=0,
+        unsaturatedFatContent=12,
+    )
+    assert n.calories == "260"
+    assert n.carbohydrateContent == "30"
+    assert n.cholesterolContent == "10"
+    assert n.fatContent == "15"
+    assert n.fiberContent == "5"
+    assert n.proteinContent == "20"
+    assert n.saturatedFatContent == "3"
+    assert n.servingSize == "1"
+    assert n.sodiumContent == "500"
+    assert n.sugarContent == "8"
+    assert n.transFatContent == "0"
+    assert n.unsaturatedFatContent == "12"
+
+
+@pytest.mark.unit
+def test_nutrition_mixed_types():
+    """Nutrition model should handle a mix of string, int, and None values."""
+    n = Nutrition(
+        calories="650 kcal",
+        proteinContent=18,
+        fatContent=None,
+    )
+    assert n.calories == "650 kcal"
+    assert n.proteinContent == "18"
+    assert n.fatContent is None