React State Management Roadmap
20 sections • 386 topics
- 1. useState Syntax and State Declaration (React.useState)
- Example: Basic useState declarations
- 2. Functional State Updates (Updater Functions)
- Example: Functional updates prevent stale closures
- 3. Lazy State Initialization with Functions
- Example: Lazy initialization for expensive operations
- 4. State Update Batching (React 18 Automatic Batching)
- Example: Automatic batching in React 18
- 5. Complex State Objects and State Merging
- Example: Object state updates and merging
- 6. State Reset Patterns and Key Changes
- Example: State reset patterns
- Example: Reset state when prop changes
- useState Best Practices Summary
- 1. useReducer Syntax and Dispatch Patterns (React.useReducer)
- Example: Basic useReducer setup and dispatch
- Example: Lazy initialization with init function
- 2. Reducer Function Patterns and Action Types
- Example: Reducer patterns comparison
- 3. Action Creators and Payload Structures
- Example: Action creators for cleaner code
- Example: TypeScript action creators with discriminated unions
- 4. State Machine Patterns with useReducer
- Example: State machine for async data fetching
- 5. useReducer vs useState - When to Use Which
- Example: When to migrate from useState to useReducer
- Migration Checklist: useState → useReducer
- 6. Async Actions and useReducer Integration
- Example: Async actions with useReducer
- Example: Custom async hook with useReducer
- useReducer Best Practices Summary
- 1. createContext and Provider Component Patterns (React.createContext)
- Example: Basic Context creation and Provider setup
- Example: Provider with useReducer for complex state
- 2. useContext Hook and Context Consumption (React.useContext)
- Example: Consuming context with useContext
- Example: Custom hook for context with validation
- 3. Multiple Context Providers and Context Composition
- Example: Multiple providers composition
- Example: Dependent contexts
- 4. Context Performance Optimization Techniques
- Example: Memoizing context value
- Example: Split context for state and dispatch
- Example: Selector pattern for granular subscriptions
- 5. Context vs Prop Drilling - When to Use Which
- Example: When prop drilling is acceptable
- Decision Framework
- 6. Context Testing and Development Patterns
- Example: Testing components with Context
- Example: Mock context for testing
- Example: TypeScript context with full type safety
- Context API Best Practices Summary
- 1. Initial State from Props and External Sources
- Example: Initialize state from props
- Example: Initialize from URL and external sources
- 2. Derived Initial State Patterns
- Example: Derived initial state patterns
- 3. State Hydration (localStorage and sessionStorage)
- Example: localStorage hydration patterns
- Example: Custom useLocalStorage hook
- Example: sessionStorage for temporary state
- 4. Controlled vs Uncontrolled Components - When to Use Which
- Example: Controlled component pattern
- Example: Uncontrolled component pattern
- Example: Hybrid approach
- 5. Default Props and State Fallback Strategies
- Example: Default prop patterns
- Example: Fallback strategies for missing data
- Example: Conditional rendering fallbacks
- State Initialization Best Practices Summary
- 1. Object State Updates (Spread Operator ...)
- Example: Object state updates
- 2. Array State Manipulation (map, filter, concat)
- Example: Array state operations
- 3. Nested Object State Updates (Immer Integration)
- Example: Manual nested updates (verbose)
- Example: Immer for cleaner nested updates
- Example: Array of objects with nested updates
- 4. State Normalization for Complex Data Structures
- Example: Denormalized vs Normalized state
- Example: Normalized state operations
- 5. Avoiding State Mutation and Side Effects
- Example: Common mutation mistakes and fixes
- Example: Avoiding side effects in render
- 6. State Update Optimization and Performance
- Example: Bail out of updates
- Example: Structural sharing
- Example: State splitting for performance
- Immutability Best Practices Summary
- 1. useMemo Hook for Expensive Calculations (React.useMemo)
- useMemo Hook Syntax
- useMemo vs Recalculation Comparison
- Example: Expensive Filtering with useMemo
- Example: Complex Calculation with useMemo
- 2. Derived State from Props and State Combinations
- Derived State Patterns
- Derived State vs Stored State Decision Matrix
- Example: Derived State from Multiple Sources
- Example: ❌ Bad - Storing Derived State
- 3. Selector Patterns for State Selection
- Selector Pattern Types
- Selector Best Practices
- Example: Selector Pattern for Complex State
- Example: Reselect Library Pattern
- 4. Custom Hooks for Derived State Logic
- Custom Hook Patterns for Derived State
- Example: useFilteredItems Custom Hook
- Example: useDebounced Custom Hook for Derived State
- Example: useSelector Pattern with Context
- 5. Avoiding Derived State Anti-patterns
- Common Derived State Anti-patterns
- Anti-pattern Detection Checklist
- Anti-pattern #1: Storing Derived Data in State
- Anti-pattern #2: Props in State (Mirror Props)
- Anti-pattern #3: Premature useMemo Optimization
- Derived State Best Practices Summary:
- 1. useEffect Hook with State Dependencies (React.useEffect)
- useEffect Hook Syntax and State Dependencies
- Common useEffect with State Patterns
- Example: Fetch Data on State Change
- Example: Sync State to localStorage
- Example: ❌ Infinite Loop Anti-pattern
- 2. State Synchronization with External Systems
- External System Synchronization Patterns
- useSyncExternalStore Hook (React 18+)
- Example: Window Resize State Synchronization
- Example: WebSocket State Synchronization
- Example: useSyncExternalStore with Custom Store
- 3. Cleanup Functions and State Management
- Cleanup Function Patterns
- Cleanup Function Execution Timing
- Example: Timer Cleanup
- Example: Abort Controller for Request Cancellation
- Example: Multiple Cleanup Operations
- 4. State and Subscription Patterns
- Subscription Pattern Types
- Subscription Best Practices
- Example: RxJS Observable Subscription
- Example: Event Emitter Subscription
- Example: Server-Sent Events (SSE) Subscription
- 5. Race Condition Prevention in State Updates
- Common Race Condition Scenarios
- Race Condition Prevention Techniques
- Example: AbortController to Prevent Race Conditions
- Example: Request ID Tracking
- Example: Debounced Search with Race Condition Prevention
- State and Side Effects Best Practices Summary:
- 1. React.memo and State Change Prevention (memo HOC)
- Example: React.memo preventing unnecessary re-renders
- 2. useCallback Hook for Event Handler Optimization (React.useCallback)
- Example: useCallback optimization patterns
- 3. State Splitting and Component Granularity
- ❌ Bad: Single state object causes unnecessary re-renders
- ✅ Good: Split state by concern
- Example: Collocating state for performance
- 4. useMemo for Expensive State Derivations (React.useMemo)
- Example: useMemo for expensive computations
- 5. Context Performance and Re-render Optimization
- ❌ Bad: All consumers re-render
- ✅ Good: Split contexts
- Example: Context selector pattern for fine-grained subscriptions
- 6. State Update Batching and FlushSync Usage (React.flushSync)
- Example: Automatic batching in React 18
- Example: flushSync for synchronous updates
- Performance Optimization Summary:
- 1. Loading State Patterns (isLoading Boolean Flags)
- Example: Multiple loading states for different operations
- 2. Error State Handling and Error Boundaries (ErrorBoundary)
- Example: Comprehensive error state management
- Example: Error Boundary for catching render errors
- 3. Success State and Data Management
- Example: Success state with metadata
- 4. useReducer for Complex Async State Machines
- Example: useReducer for async state machine
- 5. Promise-based State Updates and Race Conditions
- Example: Preventing race conditions with request ID
- Example: Preventing memory leaks on unmounted components
- 6. Abort Controllers and Cleanup for Async Operations (AbortController)
- Example: AbortController with fetch
- Example: Reusable hook with AbortController
- Example: Multiple AbortControllers for different operations
- Async State Management Summary:
- 1. Controlled Input Components and State Binding (value and onChange)
- Example: Controlled form with multiple input types
- 2. Uncontrolled Components (useRef Patterns)
- 3. Form Validation State and Error Handling
- Example: Comprehensive form validation
- 4. Multi-step Form State Management (Wizard Forms)
- Example: Multi-step form with validation
- 5. Form Reset and Clear Operations
- Example: Form reset patterns
- 6. Dynamic Form Fields and Array State Management
- Example: Dynamic fields - add/remove items
- Example: Nested dynamic fields with validation
- Form State Management Summary:
- 1. Array State Operations (CRUD) with Keys (React key prop)
- Example: Complete CRUD operations for todo list
- 2. Filtering and Sorting State Implementation
- Example: Filtering and sorting implementation
- 3. Pagination State and Virtual Scrolling
- 4. Selection State (Multi-select and Checkbox Components)
- Example: Multi-select with Set (recommended)
- 5. Drag and Drop State Management (DnD Libraries)
- Example: Drag and drop reordering
- 6. Search and Filter State with Debouncing
- Example: Custom debounce hook for search
- Example: Debounced API search with loading state
- Example: Advanced search with multiple filters
- List and Collection State Summary:
- 1. localStorage Integration with useState (localStorage.getItem)
- Example: Custom useLocalStorage hook
- 2. sessionStorage Patterns for Temporary State
- Example: useSessionStorage for form drafts
- 3. IndexedDB Integration for Complex Data
- Example: IndexedDB wrapper for React state
- 4. State Hydration and SSR Compatibility (Server-Side Rendering)
- Example: SSR-safe localStorage hook
- 5. Cross-tab State Synchronization Patterns (BroadcastChannel)
- Example: Cross-tab sync with storage event
- Example: BroadcastChannel for custom messages
- 6. State Backup and Recovery Strategies
- Example: Auto-save with recovery
- Example: Export/Import state as JSON
- State Persistence Summary:
- 1. State Machine Implementation (XState Integration)
- Example: Authentication state machine with XState
- Example: Simple state machine without XState (pure React)
- 2. Undo/Redo State Management (History Stack Pattern)
- Example: Complete undo/redo implementation with useReducer
- Example: Debounced history for text input (grouped actions)
- 3. Optimistic UI Updates and Rollback Patterns
- Example: Optimistic todo creation with rollback
- Example: Optimistic delete with undo toast
- 4. State Normalization for Relational Data (normalizedData)
- Example: Normalizing nested blog post data
- Example: Selectors to denormalize for rendering
- Example: Using Redux Toolkit's createEntityAdapter
- 5. Event Sourcing Patterns in React State
- Example: Event-sourced shopping cart
- Example: Event projections for analytics
- 6. CQRS (Command Query Responsibility Segregation) Patterns
- Example: CQRS pattern for task management
- Example: React hook for CQRS pattern
- Section 13 Key Takeaways
- 1. Redux Toolkit (RTK) Integration Patterns (@reduxjs/toolkit)
- Example: Complete Redux Toolkit setup with slice
- Example: Async thunk for API calls
- 2. Zustand Store Implementation and Usage
- Example: Complete Zustand store with actions
- Example: Zustand with persistence and DevTools
- 3. Jotai Atomic State Management
- Example: Basic Jotai atoms and derived state
- Example: Async atoms with Suspense
- 4. Valtio Proxy-based State Management
- Example: Basic Valtio state with mutations
- Example: Derived state and computed properties
- 5. Recoil Experimental State Management
- Example: Recoil atoms and selectors
- Example: Async selectors and atom families
- 6. Custom State Management Library Creation
- Example: Custom store with useSyncExternalStore
- Example: Store with selectors and computed values
- Example: Store with middleware support
- Section 14 Key Takeaways
- 1. React Query (TanStack Query) Integration (@tanstack/react-query)
- Example: Complete React Query setup
- Example: Mutations with optimistic updates
- Example: Infinite scroll with useInfiniteQuery
- 2. SWR (Stale-While-Revalidate) Patterns
- Example: Basic SWR usage with revalidation
- Example: Optimistic updates with mutate
- Example: Infinite scroll with useSWRInfinite
- 3. Apollo Client GraphQL State Management (@apollo/client)
- Example: Apollo Client setup and queries
- Example: Mutations with optimistic updates
- Example: Local state with reactive variables
- 4. Server State vs Client State - When to Use Which
- Example: Clear separation of server and client state
- Example: Anti-pattern - duplicating server state in client state
- 5. Cache Invalidation and State Synchronization
- Example: Cache invalidation patterns
- Example: WebSocket-based real-time sync
- 6. Offline State Management (Service Workers)
- Example: Offline-first with React Query and service worker
- Example: Service worker with cache strategies
- Section 15 Key Takeaways
- 1. useTransition Hook (Non-blocking State Updates)
- Example: Search with transitions for responsive input
- Example: Tab switching with smooth transitions
- 2. useDeferredValue for State Value Deferring
- Example: Deferred search results
- Example: Deferred value vs regular value comparison
- 3. Concurrent Rendering and State Consistency
- Example: Automatic batching in React 18
- Example: Pure render functions for concurrent mode
- 4. useSyncExternalStore (External State Integration)
- Example: Custom store with useSyncExternalStore
- Example: Browser API integration with selectors
- Example: Redux integration with selectors
- 5. State Prioritization and Update Scheduling
- Example: Priority comparison in action
- Example: Multiple priority levels in complex UI
- 6. Streaming SSR and State Hydration (Server-Side Rendering)
- Example: Streaming SSR with Suspense boundaries
- Example: Avoiding hydration mismatches
- Example: State serialization for SSR
- Section 16 Key Takeaways
- 1. Unit Testing State Logic (React Testing Library)
- Example: Testing Counter State with useState
- Example: Testing Async State Updates
- 2. Testing useReducer and Action Dispatching
- Example: Testing Reducer Function in Isolation
- Example: Testing useReducer Component Integration
- 3. Testing Context Providers and Consumer Components
- Example: Testing Context Provider and Consumer
- Example: Custom Render with Context Wrapper
- 4. Mock State for Component Testing (jest.mock)
- Example: Mocking useState and useEffect
- Example: Mocking Redux/Zustand Store
- 5. Integration Testing with State Management Libraries
- Example: Redux Integration Testing
- Example: React Query Integration Testing
- 6. End-to-End State Testing (Cypress and Playwright)
- Example: Cypress E2E State Testing
- Example: Playwright E2E State Testing
- Section 17 Key Takeaways
- 1. React DevTools for State Inspection (Browser Extension)
- Example: Inspecting Component State with DevTools
- Example: Using DevTools Component Displayname for Better Debugging
- 2. Redux DevTools Extension Integration
- Example: Redux Toolkit with DevTools Integration
- Example: Custom Redux DevTools Integration for Non-Redux State
- 3. State Logging and Debug Patterns (console.log)
- Example: Custom useDebugState Hook with Logging
- Example: Redux Logger Middleware
- Example: Production-Safe State Logging
- 4. Time-travel Debugging for State Changes
- Example: Custom Time-Travel Hook
- Example: Redux DevTools Time-Travel Integration
- 5. Performance Profiling for State Updates (React Profiler)
- Example: React Profiler Component for State Updates
- Example: Custom Performance Monitoring Hook
- Example: Redux Performance Monitoring Middleware
- 6. Custom Debug Hooks for State Monitoring
- Example: Comprehensive Debug Hook Collection
- Example: Using Debug Hooks in Components
- Example: Production-Safe Debug Wrapper
- Section 18 Key Takeaways
- 1. Sensitive Data Handling in State (Passwords and Tokens)
- Example: Secure Sensitive Data Handling
- Example: Secure Context for Sensitive State
- 2. State Sanitization and Validation
- Example: State Validation with Zod
- Example: Input Sanitization for HTML Content
- Example: Custom Validation Hook
- 3. XSS Prevention in Dynamic State Rendering (Cross-Site Scripting)
- Example: Safe vs Unsafe State Rendering
- Example: Safe Markdown Rendering from State
- Example: CSP Integration with React State
- 4. State Encryption for Client-side Storage (crypto-js)
- Example: Encrypted State Storage Hook
- 5. Authentication State and Token Management (JWT)
- Example: Secure Authentication State Management
- 6. State Audit Logging and Compliance
- Example: Audit Logging Middleware for Redux
- Example: GDPR-Compliant State Audit Hook
- Section 19 Key Takeaways
- 1. Flux Architecture Patterns in React
- Example: Classic Flux Pattern Implementation
- 2. Model-View-Update (MVU) Patterns (Elm Architecture)
- Example: MVU Pattern in React with TypeScript
- Example: MVU with Effects System
- 3. Unidirectional Data Flow Implementation
- Example: Enforcing Unidirectional Flow with Custom Hook
- 4. State Composition and Module Boundaries
- Example: Domain-Based State Composition
- Example: Feature-Based State Modules with Context
- 5. State Scaling Strategies for Large Applications
- Example: Dynamic Reducer Injection
- Example: State Normalization for Scalability
- Example: Virtual Scrolling for Large State
- 6. Micro-frontend State Management Strategies (Module Federation)
- Example: Shared State Bus for Micro-frontends
- Example: Custom Events for Framework-Agnostic Communication
- Example: Module Federation for Shared State
- Section 20 Key Takeaways