fix: ensure value_string is not an int or a float (#454)

Closes #453.

Author: raphael0202

src/openfoodfacts/types.py

@@ -1,7 +1,7 @@
 import enum
 from typing import Any, Dict, Literal, Optional, Union
 
-from pydantic import BaseModel, Field, model_validator
+from pydantic import BaseModel, Field, field_validator, model_validator
 
 #: A precise expectation of what mappings looks like in json.
 #: (dict where keys are always of type `str`).
@@ -931,6 +931,16 @@ class NutritionV3NutrientInput(BaseModel):
     value_string: str | None = None
     modifier: str | None = None
 
+    @field_validator("value_string", mode="before")
+    @classmethod
+    def ensure_value_string_is_not_an_int_or_float(cls, value: Any) -> Any:
+        # Sometimes, Product Opener uses an int for `value_string` instead
+        # of a string, which causes Pydantic validation to fail.
+        # See https://github.com/openfoodfacts/openfoodfacts-python/issues/452
+        if isinstance(value, int) or isinstance(value, float):
+            return str(value)
+        return value
+
 
 class NutritionV3AggregatedSet(BaseModel):
     preparation: Literal["as_sold", "prepared"]

tests/unit/test_types.py

@@ -1,6 +1,12 @@
 import pytest
 
-from openfoodfacts.types import Flavor, JSONType, NutritionV3, NutritionV3InputSet
+from openfoodfacts.types import (
+    Flavor,
+    JSONType,
+    NutritionV3,
+    NutritionV3InputSet,
+    NutritionV3NutrientInput,
+)
 
 
 def test_from_product_type_food():
@@ -420,3 +426,16 @@ def test_get_input_nutrient(self):
         assert result.value_string == "5.2"
         assert result.unit == "g"
         assert result.modifier is None
+
+
+class TestNutritionV3NutrientInput:
+    def test_ensure_value_string_is_not_an_int_or_float(self):
+        parsed = NutritionV3NutrientInput.model_validate(
+            {
+                "unit": "g",
+                "value": 5.2,
+                "value_string": 5.2,
+                "modifier": "<",
+            }
+        )
+        assert parsed.value_string == "5.2"