DDD Testing Standards

DDD Testing Standards

🎯 Mission

Créer des tests exhaustifs pour les bounded contexts DDD suivant une approche TDD (Test-Driven Development) avec des standards de coverage stricts.

🏆 Philosophie Critique

Dans DDD, les tests sont NON-NÉGOCIABLES.

La logique métier dans le Domain Layer DOIT être testée à 100% avant toute autre implémentation. Les tests sont la documentation vivante de votre logique métier.

Pourquoi TDD en DDD ?

1. Logique métier fiable : Le Domain contient les règles critiques de l'application
2. Refactoring sécurisé : Tests exhaustifs permettent de refactorer sans casser
3. Documentation : Tests décrivent le comportement attendu
4. Confidence : Déploiement en production sans peur
5. Régression : Prévenir la réintroduction de bugs

📁 Structure des Tests

bounded-context/
├── tests/
│   ├── unit/
│   │   ├── domain/
│   │   │   ├── entities/
│   │   │   │   ├── subscription.entity.spec.ts
│   │   │   │   └── club.entity.spec.ts
│   │   │   ├── value-objects/
│   │   │   │   ├── subscription-plan.vo.spec.ts
│   │   │   │   └── club-name.vo.spec.ts
│   │   │   └── services/
│   │   │       └── subscription-limit.service.spec.ts
│   │   └── application/
│   │       ├── commands/
│   │       │   ├── create-club.handler.spec.ts
│   │       │   └── subscribe-to-plan.handler.spec.ts
│   │       └── queries/
│   │           ├── get-club.handler.spec.ts
│   │           └── list-clubs.handler.spec.ts
│   └── integration/
│       └── handlers/
│           ├── create-club.integration.spec.ts
│           └── subscribe-to-plan.integration.spec.ts

🧪 1. Domain Layer Tests (MANDATORY - 100% Coverage)

Entities Tests

Objectif : Tester TOUTE la logique métier encapsulée dans les entités

Ce qui DOIT être testé :

• ✅ Tous les business methods
• ✅ Toutes les validation rules
• ✅ Toutes les state transitions
• ✅ Tous les edge cases et boundary conditions
• ✅ Tous les invariants
• ✅ Tous les factory methods

Template Entity Test

// tests/unit/domain/entities/subscription.entity.spec.ts

import { Subscription } from '../../../../domain/entities/subscription.entity';
import { SubscriptionPlan } from '../../../../domain/value-objects/subscription-plan.vo';
import { SubscriptionStatus } from '../../../../domain/value-objects/subscription-status.vo';

describe('Subscription Entity', () => {
  describe('Factory Method - create()', () => {
    it('should create a new subscription with default values', () => {
      // Arrange
      const clubId = 'club-123';
      const plan = SubscriptionPlan.FREE;

      // Act
      const subscription = Subscription.create(clubId, plan);

      // Assert
      expect(subscription.getClubId()).toBe(clubId);
      expect(subscription.getPlan()).toBe(plan);
      expect(subscription.isActive()).toBe(true);
      expect(subscription.getCurrentTeamsCount()).toBe(0);
    });

    it('should throw error when clubId is empty', () => {
      // Arrange
      const clubId = '';
      const plan = SubscriptionPlan.FREE;

      // Act & Assert
      expect(() => Subscription.create(clubId, plan)).toThrow('Club ID is required');
    });
  });

  describe('Business Method - canCreateTeam()', () => {
    it('should return true when subscription is active and limit not reached', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);

      // Act
      const result = subscription.canCreateTeam();

      // Assert
      expect(result).toBe(true);
    });

    it('should return false when subscription is inactive', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);
      subscription.deactivate(); // State transition

      // Act
      const result = subscription.canCreateTeam();

      // Assert
      expect(result).toBe(false);
    });

    it('should return false when team limit is reached', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);
      subscription.incrementTeamsCount(); // 1/1 team for FREE plan

      // Act
      const result = subscription.canCreateTeam();

      // Assert
      expect(result).toBe(false);
    });

    it('should return true when plan has unlimited teams', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.UNLIMITED);
      // Simulate many teams
      for (let i = 0; i < 100; i++) {
        subscription.incrementTeamsCount();
      }

      // Act
      const result = subscription.canCreateTeam();

      // Assert
      expect(result).toBe(true);
    });

    it('should handle null teams count gracefully', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);

      // Act
      const result = subscription.canCreateTeam();

      // Assert
      expect(result).toBe(true);
    });
  });

  describe('Business Method - upgrade()', () => {
    it('should upgrade from FREE to PRO successfully', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);

      // Act
      subscription.upgrade(SubscriptionPlan.PRO);

      // Assert
      expect(subscription.getPlan()).toBe(SubscriptionPlan.PRO);
    });

    it('should upgrade from PRO to UNLIMITED successfully', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.PRO);

      // Act
      subscription.upgrade(SubscriptionPlan.UNLIMITED);

      // Assert
      expect(subscription.getPlan()).toBe(SubscriptionPlan.UNLIMITED);
    });

    it('should throw error when trying to downgrade', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.PRO);

      // Act & Assert
      expect(() => subscription.upgrade(SubscriptionPlan.FREE))
        .toThrow('Cannot downgrade subscription');
    });

    it('should throw error when upgrading to same plan', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.PRO);

      // Act & Assert
      expect(() => subscription.upgrade(SubscriptionPlan.PRO))
        .toThrow('Already on this plan');
    });
  });

  describe('State Transition - incrementTeamsCount()', () => {
    it('should increment teams count when limit not reached', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.PRO);
      const initialCount = subscription.getCurrentTeamsCount();

      // Act
      subscription.incrementTeamsCount();

      // Assert
      expect(subscription.getCurrentTeamsCount()).toBe(initialCount + 1);
    });

    it('should throw error when limit is reached', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);
      subscription.incrementTeamsCount(); // Reach limit (1/1)

      // Act & Assert
      expect(() => subscription.incrementTeamsCount())
        .toThrow('Team limit reached for current plan');
    });

    it('should allow unlimited increments for UNLIMITED plan', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.UNLIMITED);

      // Act - Increment 1000 times
      for (let i = 0; i < 1000; i++) {
        subscription.incrementTeamsCount();
      }

      // Assert
      expect(subscription.getCurrentTeamsCount()).toBe(1000);
    });
  });

  describe('Edge Cases', () => {
    it('should handle negative teams count validation', () => {
      // Arrange & Act & Assert
      expect(() => new Subscription(
        'id-123',
        'club-123',
        SubscriptionPlan.FREE,
        SubscriptionStatus.ACTIVE,
        new Date(),
        null,
        -1, // Negative count
      )).toThrow('Teams count cannot be negative');
    });

    it('should handle null plan', () => {
      // Arrange & Act & Assert
      expect(() => new Subscription(
        'id-123',
        'club-123',
        null as any,
        SubscriptionStatus.ACTIVE,
        new Date(),
        null,
        0,
      )).toThrow('Plan is required');
    });
  });
});

Value Objects Tests

// tests/unit/domain/value-objects/subscription-plan.vo.spec.ts

import { SubscriptionPlan } from '../../../../domain/value-objects/subscription-plan.vo';

describe('SubscriptionPlan Value Object', () => {
  describe('Creation', () => {
    it('should create FREE plan', () => {
      // Act
      const plan = SubscriptionPlan.FREE;

      // Assert
      expect(plan.toString()).toBe('FREE');
      expect(plan.getMaxTeams()).toBe(1);
    });

    it('should throw error for invalid plan name', () => {
      // Act & Assert
      expect(() => SubscriptionPlan.fromString('INVALID'))
        .toThrow('Invalid plan: INVALID');
    });
  });

  describe('hasTeamLimit()', () => {
    it('should return true for FREE plan', () => {
      expect(SubscriptionPlan.FREE.hasTeamLimit()).toBe(true);
    });

    it('should return false for UNLIMITED plan', () => {
      expect(SubscriptionPlan.UNLIMITED.hasTeamLimit()).toBe(false);
    });
  });

  describe('isUpgradeFrom()', () => {
    it('should return true when upgrading from FREE to PRO', () => {
      expect(SubscriptionPlan.PRO.isUpgradeFrom(SubscriptionPlan.FREE)).toBe(true);
    });

    it('should return false when downgrading from PRO to FREE', () => {
      expect(SubscriptionPlan.FREE.isUpgradeFrom(SubscriptionPlan.PRO)).toBe(false);
    });

    it('should return false for same plan', () => {
      expect(SubscriptionPlan.PRO.isUpgradeFrom(SubscriptionPlan.PRO)).toBe(false);
    });
  });

  describe('Immutability', () => {
    it('should be immutable (same instance for same value)', () => {
      const plan1 = SubscriptionPlan.FREE;
      const plan2 = SubscriptionPlan.FREE;

      expect(plan1).toBe(plan2);
    });
  });
});

Domain Services Tests

// tests/unit/domain/services/subscription-limit.service.spec.ts

import { SubscriptionLimitService } from '../../../../domain/services/subscription-limit.service';
import { Subscription } from '../../../../domain/entities/subscription.entity';
import { SubscriptionPlan } from '../../../../domain/value-objects/subscription-plan.vo';

describe('SubscriptionLimitService', () => {
  let service: SubscriptionLimitService;

  beforeEach(() => {
    service = new SubscriptionLimitService();
  });

  describe('canAddTeam()', () => {
    it('should return true when subscription allows new team', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);

      // Act
      const result = service.canAddTeam(subscription);

      // Assert
      expect(result).toBe(true);
    });

    it('should return false when team limit is reached', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);
      subscription.incrementTeamsCount(); // Reach limit

      // Act
      const result = service.canAddTeam(subscription);

      // Assert
      expect(result).toBe(false);
    });
  });

  describe('getRemainingSlots()', () => {
    it('should return correct remaining slots for PRO plan', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.PRO);
      subscription.incrementTeamsCount(); // 1/3 teams

      // Act
      const remaining = service.getRemainingSlots(subscription);

      // Assert
      expect(remaining).toBe(2);
    });

    it('should return Infinity for UNLIMITED plan', () => {
      // Arrange
      const subscription = Subscription.create('club-123', SubscriptionPlan.UNLIMITED);

      // Act
      const remaining = service.getRemainingSlots(subscription);

      // Assert
      expect(remaining).toBe(Infinity);
    });
  });
});

🔧 2. Application Layer Tests (MANDATORY - 95%+ Coverage)

Command Handler Tests

Objectif : Tester l'orchestration des entités domain par les handlers

Ce qui DOIT être testé :

• ✅ Successful execution path
• ✅ All validation errors
• ✅ Domain exceptions handling
• ✅ Repository methods are called correctly
• ✅ Return values (IDs)

Template Command Handler Test

// tests/unit/application/commands/create-club.handler.spec.ts

import { CreateClubHandler } from '../../../../application/commands/create-club/create-club.handler';
import { CreateClubCommand } from '../../../../application/commands/create-club/create-club.command';
import { IClubRepository } from '../../../../domain/repositories/club.repository.interface';
import { Club } from '../../../../domain/entities/club.entity';

describe('CreateClubHandler', () => {
  let handler: CreateClubHandler;
  let mockClubRepository: jest.Mocked<IClubRepository>;

  beforeEach(() => {
    // Mock repository
    mockClubRepository = {
      create: jest.fn(),
      findById: jest.fn(),
      findByUserId: jest.fn(),
      update: jest.fn(),
      delete: jest.fn(),
    } as jest.Mocked<IClubRepository>;

    handler = new CreateClubHandler(mockClubRepository);
  });

  describe('execute()', () => {
    it('should create club successfully with valid data', async () => {
      // Arrange
      const command = new CreateClubCommand(
        'Volley Club Paris',
        'Best club in Paris',
        'user-123',
      );

      const mockClub = Club.create(
        command.name,
        command.description,
        command.userId,
      );

      mockClubRepository.create.mockResolvedValue(mockClub);

      // Act
      const result = await handler.execute(command);

      // Assert
      expect(result).toBe(mockClub.getId());
      expect(mockClubRepository.create).toHaveBeenCalledTimes(1);
      expect(mockClubRepository.create).toHaveBeenCalledWith(
        expect.objectContaining({
          getName: expect.any(Function),
          getDescription: expect.any(Function),
        }),
      );
    });

    it('should throw error when name is empty', async () => {
      // Arrange
      const command = new CreateClubCommand(
        '', // Empty name
        'Description',
        'user-123',
      );

      // Act & Assert
      await expect(handler.execute(command))
        .rejects
        .toThrow('Club name cannot be empty');
    });

    it('should throw error when userId is missing', async () => {
      // Arrange
      const command = new CreateClubCommand(
        'Volley Club',
        'Description',
        '', // Empty userId
      );

      // Act & Assert
      await expect(handler.execute(command))
        .rejects
        .toThrow('User ID is required');
    });

    it('should call repository.create() with correct club entity', async () => {
      // Arrange
      const command = new CreateClubCommand(
        'Volley Club Paris',
        'Best club',
        'user-123',
      );

      const mockClub = Club.create(command.name, command.description, command.userId);
      mockClubRepository.create.mockResolvedValue(mockClub);

      // Act
      await handler.execute(command);

      // Assert
      expect(mockClubRepository.create).toHaveBeenCalledWith(
        expect.objectContaining({
          getName: expect.any(Function),
        }),
      );

      const callArg = mockClubRepository.create.mock.calls[0][0];
      expect(callArg.getName().getValue()).toBe('Volley Club Paris');
    });

    it('should propagate repository errors', async () => {
      // Arrange
      const command = new CreateClubCommand('Club', 'Desc', 'user-123');
      mockClubRepository.create.mockRejectedValue(new Error('Database error'));

      // Act & Assert
      await expect(handler.execute(command))
        .rejects
        .toThrow('Database error');
    });
  });
});

Query Handler Tests

// tests/unit/application/queries/get-club.handler.spec.ts

import { GetClubHandler } from '../../../../application/queries/get-club/get-club.handler';
import { GetClubQuery } from '../../../../application/queries/get-club/get-club.query';
import { IClubRepository } from '../../../../domain/repositories/club.repository.interface';
import { Club } from '../../../../domain/entities/club.entity';
import { ClubDetailReadModel } from '../../../../application/read-models/club-detail.read-model';

describe('GetClubHandler', () => {
  let handler: GetClubHandler;
  let mockClubRepository: jest.Mocked<IClubRepository>;

  beforeEach(() => {
    mockClubRepository = {
      create: jest.fn(),
      findById: jest.fn(),
      update: jest.fn(),
      delete: jest.fn(),
    } as jest.Mocked<IClubRepository>;

    handler = new GetClubHandler(mockClubRepository);
  });

  describe('execute()', () => {
    it('should return club read model when club exists', async () => {
      // Arrange
      const query = new GetClubQuery('club-123');

      const mockClub = Club.create('Club Paris', 'Description', 'user-123');
      mockClubRepository.findById.mockResolvedValue(mockClub);

      // Act
      const result = await handler.execute(query);

      // Assert
      expect(result).toBeDefined();
      expect(result.id).toBe(mockClub.getId());
      expect(result.name).toBe('Club Paris');
      expect(mockClubRepository.findById).toHaveBeenCalledWith('club-123');
    });

    it('should throw NotFoundException when club does not exist', async () => {
      // Arrange
      const query = new GetClubQuery('non-existent-id');
      mockClubRepository.findById.mockResolvedValue(null);

      // Act & Assert
      await expect(handler.execute(query))
        .rejects
        .toThrow('Club with ID non-existent-id not found');
    });

    it('should transform domain entity to read model correctly', async () => {
      // Arrange
      const query = new GetClubQuery('club-123');
      const mockClub = Club.create('Club Paris', 'Best club', 'user-123');
      mockClubRepository.findById.mockResolvedValue(mockClub);

      // Act
      const result = await handler.execute(query);

      // Assert
      expect(result).toMatchObject({
        id: mockClub.getId(),
        name: 'Club Paris',
        description: 'Best club',
      });
    });
  });
});

🔗 3. Integration Tests (MANDATORY - Critical Workflows)

Handler → Repository → Database Integration

Objectif : Tester le flux complet de bout en bout avec une vraie base de données

Ce qui DOIT être testé :

• ✅ Complete workflows: Handler → Repository → Database
• ✅ Transactions and rollbacks
• ✅ Concurrent operations
• ✅ Real database constraints

Template Integration Test

// tests/integration/handlers/create-club.integration.spec.ts

import { Test, TestingModule } from '@nestjs/testing';
import { INestApplication } from '@nestjs/common';
import { PrismaService } from '../../../src/prisma/prisma.service';
import { CreateClubHandler } from '../../../src/club-management/application/commands/create-club/create-club.handler';
import { CreateClubCommand } from '../../../src/club-management/application/commands/create-club/create-club.command';
import { ClubRepository } from '../../../src/club-management/infrastructure/persistence/repositories/club.repository';
import { CLUB_REPOSITORY } from '../../../src/club-management/domain/repositories/club.repository.interface';

describe('CreateClubHandler Integration', () => {
  let app: INestApplication;
  let prismaService: PrismaService;
  let handler: CreateClubHandler;

  beforeAll(async () => {
    const moduleFixture: TestingModule = await Test.createTestingModule({
      providers: [
        PrismaService,
        CreateClubHandler,
        {
          provide: CLUB_REPOSITORY,
          useClass: ClubRepository,
        },
      ],
    }).compile();

    app = moduleFixture.createNestApplication();
    await app.init();

    prismaService = moduleFixture.get<PrismaService>(PrismaService);
    handler = moduleFixture.get<CreateClubHandler>(CreateClubHandler);
  });

  beforeEach(async () => {
    // Clean database before each test
    await prismaService.club.deleteMany({});
  });

  afterAll(async () => {
    await app.close();
  });

  it('should create club in database successfully', async () => {
    // Arrange
    const command = new CreateClubCommand(
      'Volley Club Integration',
      'Integration test club',
      'user-integration-123',
    );

    // Act
    const clubId = await handler.execute(command);

    // Assert
    const savedClub = await prismaService.club.findUnique({
      where: { id: clubId },
    });

    expect(savedClub).toBeDefined();
    expect(savedClub.name).toBe('Volley Club Integration');
    expect(savedClub.description).toBe('Integration test club');
    expect(savedClub.ownerId).toBe('user-integration-123');
  });

  it('should enforce database constraints (unique name per user)', async () => {
    // Arrange
    const command1 = new CreateClubCommand('Club Name', 'Desc', 'user-123');
    const command2 = new CreateClubCommand('Club Name', 'Desc 2', 'user-123');

    // Act
    await handler.execute(command1);

    // Assert
    await expect(handler.execute(command2))
      .rejects
      .toThrow(); // Database unique constraint
  });

  it('should rollback transaction on error', async () => {
    // Arrange
    const command = new CreateClubCommand(
      'Club Rollback',
      'Test rollback',
      'invalid-user-id', // Foreign key violation
    );

    // Act & Assert
    await expect(handler.execute(command)).rejects.toThrow();

    // Verify no club was created
    const clubs = await prismaService.club.findMany({});
    expect(clubs).toHaveLength(0);
  });
});

📊 Coverage Requirements

Exigences STRICTES par couche

• Domain Layer: 100% coverage (TOUS les methods, TOUTES les branches)
• Application Layer: 95%+ coverage
• Integration Tests: TOUS les workflows critiques

Commandes de coverage

# Run tests with coverage
cd volley-app-backend
yarn test:cov

# View coverage report
open coverage/lcov-report/index.html

Vérification de la coverage

// jest.config.js - Coverage thresholds
{
  "coverageThreshold": {
    "global": {
      "branches": 80,
      "functions": 80,
      "lines": 80,
      "statements": 80
    },
    "**/domain/**/*.ts": {
      "branches": 100,
      "functions": 100,
      "lines": 100,
      "statements": 100
    }
  }
}

✅ Test Naming Convention

Règle de nommage

describe('[Unit Under Test]', () => {
  describe('[Method/Feature]', () => {
    it('should [expected behavior] when [condition]', () => {
      // Test
    });
  });
});

Exemples

describe('Subscription Entity', () => {
  describe('canCreateTeam()', () => {
    it('should return true when subscription is active and limit not reached', () => {});
    it('should return false when subscription is inactive', () => {});
    it('should return false when team limit is reached', () => {});
  });
});

describe('CreateClubHandler', () => {
  describe('execute()', () => {
    it('should create club successfully with valid data', () => {});
    it('should throw ValidationException when name is missing', () => {});
  });
});

🔄 Test Execution Order (TDD Approach)

1. RED Phase (Write failing test)

it('should return true when subscription allows team creation', () => {
  const subscription = Subscription.create('club-123', SubscriptionPlan.FREE);
  expect(subscription.canCreateTeam()).toBe(true); // FAILS (method doesn't exist)
});

2. GREEN Phase (Implement minimal code to pass)

// domain/entities/subscription.entity.ts
canCreateTeam(): boolean {
  return true; // Minimal implementation
}

3. REFACTOR Phase (Improve code while keeping tests green)

canCreateTeam(): boolean {
  if (!this.isActive()) return false;
  if (!this.plan.hasTeamLimit()) return true;
  return this.currentTeamsCount < this.plan.getMaxTeams();
}

Workflow de Développement TDD

1. Écrire les tests Domain Layer FIRST (entities, value objects, services)
2. Implémenter le Domain Layer pour passer les tests (TDD)
3. Écrire les tests Application Layer (handlers)
4. Implémenter l'Application Layer
5. Écrire les Integration tests
6. Implémenter Infrastructure et Presentation layers

🛠️ Outils et Configuration

Jest Configuration

// jest.config.js
module.exports = {
  moduleFileExtensions: ['js', 'json', 'ts'],
  rootDir: 'src',
  testRegex: '.*\\.spec\\.ts$',
  transform: {
    '^.+\\.(t|j)s$': 'ts-jest',
  },
  collectCoverageFrom: [
    '**/*.(t|j)s',
    '!**/*.spec.ts',
    '!**/node_modules/**',
  ],
  coverageDirectory: '../coverage',
  testEnvironment: 'node',
};

Running Tests

# Run all tests
yarn test

# Run tests in watch mode
yarn test:watch

# Run tests with coverage
yarn test:cov

# Run specific test file
yarn test create-club.handler.spec.ts

# Run integration tests only
yarn test:e2e

🎓 Exemples Concrets du Projet

Bounded Context club-management

Tests existants à consulter :

• tests/unit/domain/entities/subscription.entity.spec.ts
• tests/unit/application/commands/create-club.handler.spec.ts
• tests/integration/handlers/subscribe-to-plan.integration.spec.ts

Référence : volley-app-backend/src/club-management/tests/

🚨 Erreurs Courantes à Éviter

1. ❌ Ne pas tester les edge cases

   • ✅ FAIRE : Tester null, undefined, limites, valeurs négatives
   • ❌ NE PAS FAIRE : Tester uniquement le happy path

2. ❌ Tests qui testent l'implémentation au lieu du comportement

   • ✅ FAIRE : Tester ce que fait la méthode (behavior)
   • ❌ NE PAS FAIRE : Tester comment elle le fait (implementation)

3. ❌ Tests qui dépendent d'autres tests

   • ✅ FAIRE : Chaque test est indépendant
   • ❌ NE PAS FAIRE : Tests qui s'exécutent dans un ordre spécifique

4. ❌ Mocks dans les tests Domain Layer

   • ✅ FAIRE : Tester les entités pures sans mocks
   • ❌ NE PAS FAIRE : Mocker des Value Objects ou Services dans les tests d'entités

5. ❌ Ne pas nettoyer la DB dans les tests d'intégration

   • ✅ FAIRE : beforeEach(() => prisma.club.deleteMany())
   • ❌ NE PAS FAIRE : Laisser les données s'accumuler

📚 Skills Complémentaires

Pour aller plus loin :

• ddd-bounded-context : Architecture DDD complète
• cqrs-command-query : Patterns CQRS pour Commands/Queries
• testing : Standards généraux de tests (unit, integration, frontend)

Rappel : Les tests sont la documentation vivante de votre logique métier. Un test bien écrit vaut mieux que 100 lignes de commentaires.