code-refactoring（代码重构）

Skill Purpose

This skill specializes in refactoring React Native code. It focuses on eliminating deeply nested conditionals, optimizing array operations and component re-renders, improving RTK Query usage patterns, and enhancing code readability while maintaining React Compiler compatibility and ESLint compliance.

Core Refactoring Principles

Simplicity is a Feature, Not a Limitation: Code complexity should only exist when it solves a problem that simple code cannot. Every abstraction, every layer of indirection, every clever pattern must justify its existence by making the code clearer or more maintainable. If a straightforward approach works, use it. Advanced techniques that make code harder to understand make bugs harder to find and fix. In a healthcare application, clarity is a safety feature.

Priority Order (Highest to Lowest):

1. Code readability and maintainability
2. RTK Query optimization (data flow determines component architecture)
3. Logical improvements and proper React patterns
4. Performance optimizations (let React Compiler handle micro-optimizations)
5. Modern React patterns (when they genuinely improve clarity)

Refactoring Workflow

Step 1: Analyze Current Pattern

• Identify the anti-pattern (nested conditionals, unoptimized loops, etc.)
• Check if the pattern violates React rules or ESLint config
• Assess impact on component re-renders

Step 2: Check RTK Query Usage

• Is data being over-fetched? → Use selectFromResult
• Are there conditional queries? → Use skipToken
• Is cache invalidation configured? → Add invalidatesTags/providesTags
• Is polling controlled? → Tie to screen focus with useFocusEffect

Step 3: Evaluate Hook Necessity

• Is useMemo wrapping simple calculations? → Remove
• Is useCallback wrapping stable references? → Remove
• Is useEffect creating derived state? → Compute during render
• Can modern React 19 patterns replace old patterns? → Suggest upgrade if clearer

Step 4: Apply Refactoring

• Extract complex logic into helper functions
• Use ts-pattern for nested conditionals in rendering
• Use early returns for nested conditionals in functions
• Stabilize references with useCallback only when passing to memoized children
• Memoize expensive computations with clear performance benefit
• Lift state when mapped components need coordination

Step 5: Verify Compliance

• All imports use path aliases (@components, @utils/*, etc.) where applicable
• Redux hooks are typed (useAppDispatch, useAppSelector)
• No Rules of Hooks violations
• React Compiler compatible (no manual object identity preservation unless necessary)
• ESLint passes

Code Generation Guidelines

When suggesting refactored code:

Always Include:

• Import statements with correct path aliases
• Type annotations for function parameters and returns
• Comments explaining WHY the refactor improves the code
• Before/after comparison when helpful

Always Explain:

• The specific anti-pattern being fixed
• How the refactor improves readability/performance
• Trade-offs (if any) of the new approach
• Which React/RTK Query pattern is being applied

Never:

• Use relative imports like ../../components when the import is covered by an alias
• Suggest React Native incompatible patterns (e.g., Suspense for data fetching is experimental in RN)
• Use plain Redux hooks (useDispatch, useSelector)
• Suggest patterns that conflict with React Compiler