fix: address PR review comments on stack best practice skills

- Fix flutter State class widget property initialization
- Add serverless caveat to rate-limiting example
- Add missing nested Pydantic models in FastAPI patterns
- Add missing imports and fix pagination robustness
- Add concrete GOOD example for widget rebuild pattern
- Add EmptyOrderError to clean architecture error hierarchy
- Fix useResilientFetch hook example with refetch callback

Author: breadoncee

skills/fastapi-endpoint-patterns/SKILL.md

@@ -76,11 +76,25 @@ class AddressRequest(BaseModel):
     state: str = Field(min_length=2, max_length=2)
     zip_code: str = Field(pattern=r"^\d{5}(-\d{4})?$")
 
+class OrderItemRequest(BaseModel):
+    product_id: int
+    quantity: int = Field(ge=1)
+    notes: str | None = None
+
 class CreateOrderRequest(BaseModel):
     items: list[OrderItemRequest] = Field(min_length=1)
     shipping_address: AddressRequest
     notes: str | None = None
 
+class OrderItemResponse(BaseModel):
+    id: int
+    product_id: int
+    quantity: int
+    unit_price: float
+    subtotal: float
+
+    model_config = {"from_attributes": True}
+
 class OrderResponse(BaseModel):
     id: int
     status: OrderStatus
@@ -324,6 +338,11 @@ async def create_user(
 
 ```python
 from pydantic import BaseModel, Field
+from typing import Generic, TypeVar
+import math
+from sqlalchemy import func, select
+
+T = TypeVar("T")
 
 class PaginationParams(BaseModel):
     page: int = Field(1, ge=1)
@@ -345,7 +364,7 @@ async def list_users(
     pagination: PaginationParams = Depends(),
     db: AsyncSession = Depends(get_db),
 ):
-    total = await db.scalar(select(func.count(User.id)))
+    total = await db.scalar(select(func.count(User.id))) or 0
     result = await db.execute(
         select(User)
         .offset(pagination.offset)
@@ -359,7 +378,7 @@ async def list_users(
         total=total,
         page=pagination.page,
         size=pagination.size,
-        pages=math.ceil(total / pagination.size),
+        pages=math.ceil(total / pagination.size) if pagination.size > 0 else 0,
     )
 ```
 

skills/flutter-state-management/SKILL.md

@@ -47,9 +47,15 @@ class LikeButton extends StatefulWidget {
 }
 
 class _LikeButtonState extends State<LikeButton> {
-  late int _count = widget.initialCount;
+  late int _count;
   bool _isLiked = false;
 
+  @override
+  void initState() {
+    super.initState();
+    _count = widget.initialCount;
+  }
+
   void _toggleLike() {
     setState(() {
       _isLiked = !_isLiked;

skills/flutter-widget-patterns/SKILL.md

@@ -395,6 +395,38 @@ class _MyState extends State<MyWidget> {
   }
 }
 
-// GOOD: Extract counter into its own widget
-// ExpensiveHeader and ExpensiveFooter are const and skip rebuilds
+// GOOD: Extract the changing part into its own widget
+class MyWidget extends StatelessWidget {
+  const MyWidget({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        const ExpensiveHeader(),   // Never rebuilds
+        const CounterText(),       // Only this rebuilds
+        const ExpensiveFooter(),   // Never rebuilds
+      ],
+    );
+  }
+}
+
+class CounterText extends StatefulWidget {
+  const CounterText({super.key});
+
+  @override
+  State<CounterText> createState() => _CounterTextState();
+}
+
+class _CounterTextState extends State<CounterText> {
+  int _counter = 0;
+
+  @override
+  Widget build(BuildContext context) {
+    return GestureDetector(
+      onTap: () => setState(() => _counter++),
+      child: Text('$_counter'),
+    );
+  }
+}
 ```

skills/nextjs-api-patterns/SKILL.md

@@ -359,6 +359,8 @@ export async function updateProfile(formData: FormData) {
 
 ## Rate Limiting
 
+> **Note:** The in-memory example below is for demonstration only. In serverless or distributed environments (e.g., Vercel), the `Map` resets with each function invocation. For production, use Redis, Upstash, or a similar persistent store.
+
 ```tsx
 // lib/rate-limit.ts
 const rateLimit = new Map<string, { count: number; resetTime: number }>();

skills/python-clean-architecture/SKILL.md

@@ -331,6 +331,10 @@ class InactiveUserError(DomainError):
 class OrderNotEditableError(DomainError):
     def __init__(self, order_id: str, status: str):
         super().__init__(f"Order {order_id} cannot be edited in status '{status}'")
+
+class EmptyOrderError(DomainError):
+    def __init__(self, order_id: str):
+        super().__init__(f"Order {order_id} cannot be submitted with no items")
 ```
 
 ### Mapping Domain Errors to HTTP

skills/react-hook-patterns/SKILL.md

@@ -319,17 +319,20 @@ function useOnlineStatus() {
 // Composed hook
 function useResilientFetch<T>(url: string) {
   const isOnline = useOnlineStatus();
-  const result = useFetch<T>(isOnline ? url : null);
+  const [fetchKey, setFetchKey] = useState(0);
+  const result = useFetch<T>(isOnline ? url : null, fetchKey);
   const debouncedRetry = useDebounce(isOnline, 2000);
 
+  const refetch = useCallback(() => setFetchKey((k) => k + 1), []);
+
   // Auto-retry when coming back online (debounced)
   useEffect(() => {
     if (debouncedRetry && result.status === "error") {
-      // trigger refetch by remounting
+      refetch();
     }
-  }, [debouncedRetry, result.status]);
+  }, [debouncedRetry, result.status, refetch]);
 
-  return { ...result, isOnline };
+  return { ...result, isOnline, refetch };
 }
 ```