Backend Complete: Interface Refactoring & Service Container Enhancements

Repository Interface Optimization:
- Created IBaseRepository.ts and IPaginatedRepository.ts
- Refactored all 7 repository interfaces to extend base interfaces
- Eliminated ~200 lines of redundant code (70% reduction)
- Improved type safety and maintainability

 Dependency Injection Improvements:
- Added EmailService and GameTokenService to DIContainer
- Updated CreateUserCommandHandler constructor for DI
- Updated RequestPasswordResetCommandHandler constructor for DI
- Enhanced testability and service consistency

 Environment Configuration:
- Created comprehensive .env.example with 40+ variables
- Organized into 12 logical sections (Database, Security, Email, etc.)
- Added security guidelines and best practices
- Documented all backend environment requirements

 Documentation:
- Added comprehensive codebase review
- Created refactoring summary report
- Added frontend implementation guide

Impact: Improved code quality, reduced maintenance overhead, enhanced developer experience

SerpentRace_Backend/tests/Application/DTOs/Mappers/DeckMapper.test.ts

@@ -0,0 +1,187 @@
+import { DeckMapper } from '../../../../src/Application/DTOs/Mappers/DeckMapper';
+import { Type, CType, State } from '../../../../src/Domain/Deck/DeckAggregate';
+
+describe('DeckMapper', () => {
+  const createMockDeck = (overrides: any = {}) => ({
+    id: 'deck-123',
+    name: 'Test Deck',
+    type: Type.LUCK,
+    userid: 'user-123',
+    creationdate: new Date('2024-01-01'),
+    cards: [
+      { text: 'Test card 1', answer: 'Answer 1' },
+      { text: 'Test card 2' }
+    ],
+    playedNumber: 5,
+    ctype: CType.PUBLIC,
+    updatedate: new Date('2024-01-02'),
+    state: State.ACTIVE,
+    organization: null,
+    ...overrides
+  });
+
+  describe('toShortDto', () => {
+    it('should map DeckAggregate to ShortDeckDto correctly', () => {
+      // Arrange
+      const deck = createMockDeck();
+
+      // Act
+      const result = DeckMapper.toShortDto(deck);
+
+      // Assert
+      expect(result).toEqual({
+        id: 'deck-123',
+        name: 'Test Deck',
+        type: Type.LUCK,
+        playedNumber: 5,
+        ctype: CType.PUBLIC
+      });
+    });
+
+    it('should handle different deck types', () => {
+      // Arrange
+      const jokeDeck = createMockDeck({
+        id: 'joker-deck',
+        name: 'Joker Deck',
+        type: Type.JOKER,
+        playedNumber: 10
+      });
+
+      // Act
+      const result = DeckMapper.toShortDto(jokeDeck);
+
+      // Assert
+      expect(result.type).toBe(Type.JOKER);
+      expect(result.playedNumber).toBe(10);
+    });
+
+    it('should handle private decks', () => {
+      // Arrange
+      const privateDeck = createMockDeck({
+        ctype: CType.PRIVATE,
+        playedNumber: 0
+      });
+
+      // Act
+      const result = DeckMapper.toShortDto(privateDeck);
+
+      // Assert
+      expect(result.ctype).toBe(CType.PRIVATE);
+      expect(result.playedNumber).toBe(0);
+    });
+  });
+
+  describe('toDetailDto', () => {
+    it('should map DeckAggregate to DetailDeckDto correctly', () => {
+      // Arrange
+      const deck = createMockDeck();
+
+      // Act
+      const result = DeckMapper.toDetailDto(deck);
+
+      // Assert
+      expect(result).toEqual({
+        id: 'deck-123',
+        name: 'Test Deck',
+        type: Type.LUCK,
+        userid: 'user-123',
+        creationdate: new Date('2024-01-01'),
+        cards: [
+          { text: 'Test card 1', answer: 'Answer 1' },
+          { text: 'Test card 2' }
+        ],
+        playedNumber: 5,
+        ctype: CType.PUBLIC
+      });
+    });
+
+    it('should handle empty cards array', () => {
+      // Arrange
+      const deckWithNoCards = createMockDeck({
+        cards: []
+      });
+
+      // Act
+      const result = DeckMapper.toDetailDto(deckWithNoCards);
+
+      // Assert
+      expect(result.cards).toEqual([]);
+    });
+
+    it('should handle question type deck', () => {
+      // Arrange
+      const questionDeck = createMockDeck({
+        type: Type.QUESTION,
+        cards: [
+          { text: 'Question 1?', answer: 'Answer 1' },
+          { text: 'Question 2?', answer: null }
+        ]
+      });
+
+      // Act
+      const result = DeckMapper.toDetailDto(questionDeck);
+
+      // Assert
+      expect(result.type).toBe(Type.QUESTION);
+      expect(result.cards).toHaveLength(2);
+      expect(result.cards[1].answer).toBeNull();
+    });
+  });
+
+  describe('toShortDtoList', () => {
+    it('should map array of DeckAggregate to array of ShortDeckDto', () => {
+      // Arrange
+      const decks = [
+        createMockDeck({ id: 'deck-1', name: 'First Deck' }),
+        createMockDeck({ id: 'deck-2', name: 'Second Deck', type: Type.JOKER }),
+        createMockDeck({ id: 'deck-3', name: 'Third Deck', ctype: CType.PRIVATE })
+      ];
+
+      // Act
+      const result = DeckMapper.toShortDtoList(decks);
+
+      // Assert
+      expect(result).toHaveLength(3);
+      expect(result[0]).toEqual({
+        id: 'deck-1',
+        name: 'First Deck',
+        type: Type.LUCK,
+        playedNumber: 5,
+        ctype: CType.PUBLIC
+      });
+      expect(result[1].type).toBe(Type.JOKER);
+      expect(result[2].ctype).toBe(CType.PRIVATE);
+    });
+
+    it('should handle empty array', () => {
+      // Arrange
+      const decks: any[] = [];
+
+      // Act
+      const result = DeckMapper.toShortDtoList(decks);
+
+      // Assert
+      expect(result).toEqual([]);
+      expect(result).toHaveLength(0);
+    });
+
+    it('should handle large arrays', () => {
+      // Arrange
+      const decks = Array.from({ length: 50 }, (_, i) =>
+        createMockDeck({
+          id: `deck-${i + 1}`,
+          name: `Deck ${i + 1}`,
+          playedNumber: i
+        })
+      );
+
+      // Act
+      const result = DeckMapper.toShortDtoList(decks);
+
+      // Assert
+      expect(result).toHaveLength(50);
+      expect(result[0].playedNumber).toBe(0);
+      expect(result[49].playedNumber).toBe(49);
+    });
+  });
+});