Disallow empty ingredients

api/meals.py

@@ -242,6 +242,13 @@ async def create_meal_scoped(
         )
         if not has_product and name == "" and line == "":
             return error_response(request, 400, "Ingredient must include a name or line or a product")
+        # quantity must be > 0
+        try:
+            q = float(getattr(ing, "quantity", 0))
+        except Exception:
+            q = getattr(ing, "quantity", 0)
+        if isinstance(q, (int, float)) and q <= 0:
+            return error_response(request, 400, "Ingredient quantity must be greater than 0")
     # Proactive validation via repositories
     hid = household["id"]
     # Validate members exist as users (do not require household membership here to preserve existing behavior/tests)
@@ -386,6 +393,12 @@ async def update_meal_scoped(
         )
         if not has_product and name == "" and line == "":
             return error_response(request, 400, "Ingredient must include a name or line or a product")
+        try:
+            q = float(getattr(ing, "quantity", 0))
+        except Exception:
+            q = getattr(ing, "quantity", 0)
+        if isinstance(q, (int, float)) and q <= 0:
+            return error_response(request, 400, "Ingredient quantity must be greater than 0")
 
     await meals.update_meal(conn, domain_meal)
     # Return updated state

api/recipes.py

@@ -198,6 +198,13 @@ async def create_recipe(
         )
         if not has_product and name == "" and line == "":
             return error_response(None, 400, "Ingredient must include a name or line or a product")
+        # quantity must be > 0
+        try:
+            q = float(getattr(ing, "quantity", 0))
+        except Exception:
+            q = getattr(ing, "quantity", 0)
+        if isinstance(q, (int, float)) and q <= 0:
+            return error_response(None, 400, "Ingredient quantity must be greater than 0")
     hid = household["id"]
     # Build domain model and insert
     r = recipes.Recipe(

ingredients/models.py

@@ -47,6 +47,16 @@ class Ingredient(ApiModel):
                 return v
         return v
 
+    # Quantity must be > 0
+    @field_validator("quantity")
+    @classmethod
+    def _positive_quantity(cls, v: float) -> float:
+        if v is None:
+            return v
+        if isinstance(v, (int, float)) and v <= 0:
+            raise ValueError("Ingredient quantity must be greater than 0")
+        return v
+
     # Backward compatibility: DB may contain NULL preparation; normalize to empty string
     @field_validator("preparation", mode="before")
     @classmethod

ingredients/repository.py

@@ -44,6 +44,14 @@ async def insert_ingredient(conn, ingredient: Ingredient):
     if not has_product and name == "" and line == "":
         raise ValueError("Ingredient must include a name or line or a product")
 
+    # Enforce positive quantity at repository layer as well
+    try:
+        q = float(ingredient.quantity)
+    except Exception:
+        q = ingredient.quantity
+    if isinstance(q, (int, float)) and q <= 0:
+        raise ValueError("Ingredient quantity must be greater than 0")
+
     async with conn.execute(
         """
         INSERT INTO Ingredient (name, line, preparation, unit, quantity, product_id, recipe_id, meal_id)