Redux vs TDI2 Comparison

Redux vs TDI2 Comparison

Traditional State Management vs Service-Oriented Architecture

Compare Redux’s action-based state management with TDI2’s service-oriented approach for enterprise React applications.

🎯 Key Differences

• Redux - Global state + actions + reducers + selectors
• TDI2 - Services + reactive state + dependency injection
• Complexity - Redux: 4 files per feature vs TDI2: 2 files per feature
• Boilerplate - Redux: ~100 lines vs TDI2: ~40 lines

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Architecture Comparison

Redux Architecture

Components → useSelector/useDispatch → Store → Reducers → Actions → API
     ↓              ↓                    ↓        ↓         ↓        ↓
  Rendering → State Selection → Global State → State Updates → Side Effects → Data

Characteristics:

• Central global store
• Immutable state updates
• Action-based state changes
• Selector-based data access

TDI2 Architecture

Components → Service Injection → Services → Repositories → API
     ↓              ↓             ↓           ↓            ↓
  Rendering → Direct Access → Business Logic → Data Access → Data

Characteristics:

• Distributed service layer
• Reactive state (mutable)
• Method-based operations
• Direct service access

---

Side-by-Side Implementation

E-Commerce Shopping Cart Example

Redux Implementation

1. Action Types & Creators (40+ lines)

actions/cartActions.ts

export const ADD_TO_CART = 'ADD_TO_CART';
export const REMOVE_FROM_CART = 'REMOVE_FROM_CART';
export const UPDATE_QUANTITY = 'UPDATE_QUANTITY';
export const CALCULATE_TOTALS = 'CALCULATE_TOTALS';

export const addToCart = (product: Product, quantity: number) => ({
  type: ADD_TO_CART as const,
  payload: { product, quantity }
});

export const removeFromCart = (productId: string) => ({
  type: REMOVE_FROM_CART as const,
  payload: { productId }
});

export const updateQuantity = (productId: string, quantity: number) => ({
  type: UPDATE_QUANTITY as const,
  payload: { productId, quantity }
});

export const calculateTotals = () => ({
  type: CALCULATE_TOTALS as const
});

export type CartAction =
  | ReturnType<typeof addToCart>
  | ReturnType<typeof removeFromCart>
  | ReturnType<typeof updateQuantity>
  | ReturnType<typeof calculateTotals>;

2. Reducer (50+ lines)

reducers/cartReducer.ts

interface CartState {
  items: CartItem[];
  subtotal: number;
  tax: number;
  total: number;
}

const initialState: CartState = {
  items: [],
  subtotal: 0,
  tax: 0,
  total: 0
};

export const cartReducer = (
  state = initialState,
  action: CartAction
): CartState => {
  switch (action.type) {
    case ADD_TO_CART: {
      const { product, quantity } = action.payload;
      const existingItem = state.items.find(item => item.productId === product.id);

      if (existingItem) {
        return {
          ...state,
          items: state.items.map(item =>
            item.productId === product.id
              ? { ...item, quantity: item.quantity + quantity }
              : item
          )
        };
      }

      return {
        ...state,
        items: [...state.items, { productId: product.id, product, quantity, price: product.price }]
      };
    }

    case CALCULATE_TOTALS: {
      const subtotal = state.items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
      const tax = subtotal * 0.08;
      const total = subtotal + tax;

      return { ...state, subtotal, tax, total };
    }

    // ... other cases
    default:
      return state;
  }
};

3. Selectors (20+ lines)

selectors/cartSelectors.ts

export const selectCartItems = (state: RootState) => state.cart.items;
export const selectCartTotal = (state: RootState) => state.cart.total;
export const selectCartSubtotal = (state: RootState) => state.cart.subtotal;
export const selectCartTax = (state: RootState) => state.cart.tax;
export const selectCartItemCount = (state: RootState) =>
  state.cart.items.reduce((sum, item) => sum + item.quantity, 0);

4. Component Usage (30+ lines)

components/CartSummary.tsx

function CartSummary() {
  const dispatch = useDispatch();
  const items = useSelector(selectCartItems);
  const total = useSelector(selectCartTotal);
  const subtotal = useSelector(selectCartSubtotal);
  const tax = useSelector(selectCartTax);
  const itemCount = useSelector(selectCartItemCount);

  useEffect(() => {
    dispatch(calculateTotals());
  }, [items, dispatch]);

  const handleAddToCart = (product: Product) => {
    dispatch(addToCart(product, 1));
  };

  const handleRemoveFromCart = (productId: string) => {
    dispatch(removeFromCart(productId));
  };

  return (
    <div>
      <div>Items: {itemCount}</div>
      <div>Subtotal: ${subtotal.toFixed(2)}</div>
      <div>Tax: ${tax.toFixed(2)}</div>
      <div>Total: ${total.toFixed(2)}</div>
    </div>
  );
}

Total Redux Code: ~140 lines across 4 files

TDI2 Implementation

1. Service Interface (15 lines)

services/interfaces/CartServiceInterface.ts

interface CartServiceInterface {
  state: {
    items: CartItem[];
    subtotal: number;
    tax: number;
    total: number;
  };
  addToCart(product: Product, quantity?: number): void;
  removeFromCart(productId: string): void;
  updateQuantity(productId: string, quantity: number): void;
  getItemCount(): number;
}

2. Service Implementation (25 lines)

services/implementations/CartService.ts

@Service()
export class CartService implements CartServiceInterface {
  state = {
    items: [] as CartItem[],
    subtotal: 0,
    tax: 0,
    total: 0
  };

  addToCart(product: Product, quantity = 1): void {
    const existingItem = this.state.items.find(item => item.productId === product.id);

    if (existingItem) {
      existingItem.quantity += quantity;
    } else {
      this.state.items.push({ productId: product.id, product, quantity, price: product.price });
    }

    this.calculateTotals();
  }

  removeFromCart(productId: string): void {
    this.state.items = this.state.items.filter(item => item.productId !== productId);
    this.calculateTotals();
  }

  private calculateTotals(): void {
    this.state.subtotal = this.state.items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
    this.state.tax = this.state.subtotal * 0.08;
    this.state.total = this.state.subtotal + this.state.tax;
  }

  getItemCount(): number {
    return this.state.items.reduce((sum, item) => sum + item.quantity, 0);
  }
}

3. Component Usage (15 lines)

components/CartSummary.tsx

function CartSummary({ cartService }: {
  cartService: Inject<CartServiceInterface>;
}) {
  const { subtotal, tax, total } = cartService.state;
  const itemCount = cartService.getItemCount();

  return (
    <div>
      <div>Items: {itemCount}</div>
      <div>Subtotal: ${subtotal.toFixed(2)}</div>
      <div>Tax: ${tax.toFixed(2)}</div>
      <div>Total: ${total.toFixed(2)}</div>
    </div>
  );
}

Total TDI2 Code: ~55 lines across 2 files

---

Feature Comparison

Feature	Redux	TDI2	Winner
Boilerplate	High (actions, reducers, selectors)	Low (interface + implementation)	🏆 TDI2
Type Safety	Complex (union types, action creators)	Simple (TypeScript interfaces)	🏆 TDI2
Testing	Multiple layers (actions, reducers, selectors)	Single layer (service methods)	🏆 TDI2
Performance	Manual optimization (memoization)	Automatic (reactive snapshots)	🏆 TDI2
DevTools	Excellent time-travel debugging	Basic debugging	🏆 Redux
Learning Curve	Steep (many concepts)	Moderate (familiar OOP patterns)	🏆 TDI2
Component Coupling	Tight (useSelector dependencies)	Loose (interface-based injection)	🏆 TDI2
Async Operations	Complex (thunks/sagas)	Simple (async/await in services)	🏆 TDI2

---

When to Choose Each

Choose Redux When:

• Time-travel debugging is critical for your application
• Existing Redux codebase with significant investment
• Team expertise in Redux patterns is high
• Global state sharing across many unrelated components

Choose TDI2 When:

• Rapid development is a priority
• Testing simplicity is important
• Team scaling requires clear architectural boundaries
• Props drilling is causing significant development pain
• Enterprise patterns (DI, services) are familiar to your team

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Migration Path from Redux

Step 1: Gradual Service Introduction

// Start with adapter pattern
@Service()
export class ReduxCartAdapter implements CartServiceInterface {
  constructor(@Inject() private store: Store) {}

  get state() {
    return this.store.getState().cart; // Bridge to Redux
  }

  addToCart(product: Product, quantity: number): void {
    this.store.dispatch(addToCart(product, quantity)); // Delegate to Redux
  }
}

Step 2: Feature-by-Feature Migration

// New features use TDI2 services
@Service()
export class ProductService {
  state = { products: [] };
  // Pure TDI2 implementation
}

// Legacy features keep Redux
// Gradually migrate based on development priorities

Step 3: Complete Transition

// Remove Redux store, actions, reducers
// All state management through TDI2 services
// Clean, service-oriented architecture

---

Performance Comparison

Bundle Size Impact

• Redux: +45kb (Redux Toolkit + React-Redux + DevTools)
• TDI2: +12kb (Core + Valtio)
• Savings: 33kb smaller bundles

Runtime Performance

• Redux: Manual optimization with useSelector and reselect
• TDI2: Automatic optimization with Valtio snapshots
• Developer Experience: Less performance debugging needed

Development Speed

• Redux: 3-4 files per feature, complex testing setup
• TDI2: 2 files per feature, simple testing
• Time Savings: 40-60% faster feature development

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Team Productivity Analysis

Redux Team Challenges:

• New developers need 2-3 weeks to understand Redux patterns
• Complex testing requires mocking store, actions, and selectors
• Prop drilling still exists for component-specific state
• Merge conflicts in shared reducers and action files

TDI2 Team Benefits:

• New developers productive in 3-5 days with familiar service patterns
• Simple service testing with direct method calls
• Zero prop drilling with service injection
• Clear service ownership prevents merge conflicts

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Next Steps

Learn More About TDI2

• Migration Strategy - Step-by-step Redux migration
• Service Patterns - Advanced service design
• Enterprise Implementation - Large team adoption

Compare with Other Solutions

• Context API vs TDI2 - Provider pattern comparison
• Zustand vs TDI2 - Modern state management comparison

Examples

• Redux Migration Example - Complete migration walkthrough
• Performance Benchmarks - Detailed performance analysis

🎯 Key Takeaway

Redux excels at time-travel debugging and complex state coordination, but TDI2 provides significantly faster development with simpler testing and better architectural patterns for most enterprise applications.