# Testing Strategy Documentation

# Overview

This document outlines the comprehensive testing strategy for the MSPR 3 pandemic surveillance platform, covering all aspects of automated testing within our CI/CD pipeline.

# Testing Pyramid

                 E2E Tests
                /         \
           Integration Tests
          /                 \
     Unit Tests              \
    /          \              \
API Tests    Frontend Tests   Security Tests

# Test Categories

# 1. Unit Tests

Purpose: Test individual functions, methods, and components in isolation

Coverage Areas:

Route handlers
Middleware functions
Utility functions
Data transformation functions
Authentication logic

Tools:

Jest (Testing framework)
Supertest (HTTP assertions)
TypeScript support via ts-jest

Example Test Structure:

describe('Authentication Middleware', () => {
  it('should authenticate valid Bearer token', () => {
    // Test implementation
  });
  
  it('should reject invalid token', () => {
    // Test implementation
  });
});

# 2. Integration Tests

Purpose: Test interactions between different components and external services

Coverage Areas:

API endpoint workflows
Database interactions
Service integrations
Error handling across components

Test Scenarios:

Full request/response cycles
Database transaction handling
External API communication
Error propagation

# 3. Security Tests

Purpose: Verify security measures and vulnerability prevention

Coverage Areas:

Authentication bypass attempts
SQL injection prevention
XSS protection
Rate limiting effectiveness
Input validation

Security Test Types:

describe('Security Tests', () => {
  it('should prevent SQL injection in queries', () => {
    // Test malicious SQL inputs
  });
  
  it('should enforce rate limiting', () => {
    // Test request throttling
  });
});

# 4. Performance Tests

Purpose: Ensure application performance under various loads

Test Types:

Load testing (normal traffic)
Stress testing (peak traffic)
Spike testing (sudden traffic increases)
Volume testing (large data sets)

# Test Organization

# Directory Structure

tests/
├── unit/
│   ├── routes/
│   │   ├── public.test.ts
│   │   └── authenticated.test.ts
│   ├── middleware/
│   │   └── auth.test.ts
│   └── utils/
│       └── transformers.test.ts
├── integration/
│   ├── api.integration.test.ts
│   └── database.integration.test.ts
├── security/
│   ├── auth.security.test.ts
│   └── injection.security.test.ts
├── performance/
│   └── load.performance.test.ts
└── fixtures/
    ├── mockData.ts
    └── testHelpers.ts

# Test Configuration

# Jest Configuration (`jest.config.js`)

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  
  // Test patterns
  testMatch: [
    '**/__tests__/**/*.+(ts|tsx|js)',
    '**/*.(test|spec).+(ts|tsx|js)'
  ],
  
  // Coverage configuration
  collectCoverageFrom: [
    'src/**/*.{ts,tsx}',
    '!src/**/*.d.ts',
    '!src/**/index.ts',
  ],
  
  // Coverage thresholds
  coverageThreshold: {
    global: {
      branches: 80,
      functions: 80,
      lines: 80,
      statements: 80
    }
  },
  
  // Test environment setup
  setupFilesAfterEnv: ['<rootDir>/tests/setup.ts'],
  
  // Timeout configuration
  testTimeout: 30000,
  
  // Mock configurations
  moduleNameMapping: {
    '^@/(.*)$': '<rootDir>/src/$1'
  }
};

# Test Data Management

# Mock Data Strategy

Principles:

Deterministic test data
Realistic data structures
Isolated test environments
Reusable mock objects

Mock Implementation:

// tests/fixtures/mockData.ts
export const mockCovidData = [
  {
    index: 1,
    date: new Date('2024-01-01'),
    country: 'France',
    total_cases: 1000,
    new_cases: 50,
    total_deaths: 100,
    new_deaths: 5,
  }
];

export const mockPrismaClient = {
  covidData: {
    findMany: jest.fn(),
    create: jest.fn(),
    update: jest.fn(),
    delete: jest.fn(),
  }
};

# Database Testing

Strategy:

In-memory database for unit tests
Containerized PostgreSQL for integration tests
Database migrations in test environment
Transaction rollback for isolation

Setup Example:

// Database setup for integration tests
beforeAll(async () => {
  // Start test database container
  await startTestDatabase();
  
  // Run migrations
  await runMigrations();
});

beforeEach(async () => {
  // Start transaction
  await db.query('BEGIN');
});

afterEach(async () => {
  // Rollback transaction
  await db.query('ROLLBACK');
});

# Continuous Integration Testing

# Pipeline Integration

Test Execution Flow:

Pre-commit: Basic linting and type checking
Pull Request: Full test suite execution
Merge: Security and performance tests
Deploy: Smoke tests and health checks

Matrix Testing:

strategy:
  matrix:
    node-version: [18.x, 20.x]
    database-version: [13, 14, 15]
    environment: [test, staging]

# Parallel Test Execution

Benefits:

Faster feedback cycles
Resource optimization
Better CI/CD throughput

Configuration:

jobs:
  unit-tests:
    runs-on: ubuntu-latest
    # Unit test execution
    
  integration-tests:
    runs-on: ubuntu-latest
    needs: unit-tests
    # Integration test execution
    
  security-tests:
    runs-on: ubuntu-latest
    # Security test execution

# Test Quality Metrics

# Coverage Metrics

Target Thresholds:

Line Coverage: 80%
Branch Coverage: 80%
Function Coverage: 80%
Statement Coverage: 80%

Exclusions:

Configuration files
Type definitions
Generated code
Third-party integrations

# Quality Gates

Automated Checks:

All tests must pass
Coverage thresholds met
No critical security vulnerabilities
Performance benchmarks satisfied

Failure Handling:

// Graceful test failure handling
afterEach(async () => {
  if (testFailed) {
    await captureErrorLogs();
    await saveTestArtifacts();
  }
});

# Performance Testing

# Load Testing Strategy

Scenarios:

Normal Load: Expected daily traffic patterns
Peak Load: Maximum expected concurrent users
Stress Load: Beyond normal capacity limits
Spike Load: Sudden traffic increases

Metrics Tracked:

Response time percentiles (95th, 99th)
Throughput (requests per second)
Error rates
Resource utilization

# Performance Test Implementation

describe('Performance Tests', () => {
  it('should handle 1000 concurrent requests', async () => {
    const requests = Array(1000).fill(null).map(() =>
      request(app).get('/api/covid/public/latest')
    );
    
    const startTime = Date.now();
    const responses = await Promise.all(requests);
    const duration = Date.now() - startTime;
    
    expect(responses.every(r => r.status === 200)).toBe(true);
    expect(duration).toBeLessThan(5000); // 5 seconds
  });
});

# Security Testing

# Authentication Testing

Test Scenarios:

Valid token authentication
Invalid token rejection
Token expiration handling
Malformed header processing

Implementation:

describe('Authentication Security', () => {
  it('should reject requests without Bearer token', async () => {
    const response = await request(app)
      .get('/api/protected-endpoint')
      .expect(401);
      
    expect(response.body.error).toContain('Access denied');
  });
});

# Input Validation Testing

Vulnerability Categories:

SQL injection
NoSQL injection
XSS attacks
Command injection
Path traversal

Test Implementation:

describe('Input Validation', () => {
  it('should prevent SQL injection in country parameter', async () => {
    const maliciousInput = "'; DROP TABLE covid_data; --";
    
    const response = await request(app)
      .get(`/api/covid/public/country/${maliciousInput}`)
      .expect(400);
      
    // Verify database integrity
    const tableExists = await checkTableExists('covid_data');
    expect(tableExists).toBe(true);
  });
});

# Test Maintenance

# Regular Maintenance Tasks

Weekly:

Review test failures and flaky tests
Update test data for relevance
Monitor test execution times

Monthly:

Analyze coverage trends
Review and update test strategies
Optimize slow-running tests

Quarterly:

Major test framework updates
Performance benchmark reviews
Security test strategy updates

# Test Debugging

Debug Strategies:

Verbose Logging: Enable detailed test output
Isolation: Run individual test suites
Snapshot Testing: Compare test outputs
Mock Inspection: Verify mock call patterns

Debug Configuration:

// Enable debug mode for specific tests
const DEBUG = process.env.DEBUG === 'true';

beforeEach(() => {
  if (DEBUG) {
    console.log('Test environment:', process.env.NODE_ENV);
    console.log('Database URL:', process.env.DATABASE_URL);
  }
});

# Best Practices

# Test Writing Guidelines

Structure:

Arrange: Set up test data and environment
Act: Execute the function or endpoint
Assert: Verify expected outcomes

Naming Conventions:

describe('Component/Function Name', () => {
  describe('when condition', () => {
    it('should expected behavior', () => {
      // Test implementation
    });
  });
});

# Mock Management

Principles:

Mock external dependencies
Reset mocks between tests
Verify mock interactions
Use realistic mock data

Implementation:

beforeEach(() => {
  jest.clearAllMocks();
  mockPrismaClient.covidData.findMany.mockResolvedValue(mockData);
});

afterEach(() => {
  expect(mockPrismaClient.covidData.findMany).toHaveBeenCalledTimes(1);
});

# Error Testing

Error Scenarios:

Network failures
Database connection issues
Invalid input data
Rate limit exceeded
Server timeouts

Error Test Pattern:

it('should handle database connection failure', async () => {
  mockPrismaClient.covidData.findMany.mockRejectedValue(
    new Error('Database connection failed')
  );
  
  const response = await request(app)
    .get('/api/covid/public/latest')
    .expect(500);
    
  expect(response.body.error).toContain('Database connection failed');
});

# Reporting and Analytics

# Test Reports

Generated Reports:

Coverage reports (HTML, LCOV)
Test execution summaries
Performance benchmarks
Security scan results

Report Locations:

coverage/
├── lcov-report/index.html
├── lcov.info
└── clover.xml

test-results/
├── junit.xml
├── performance-report.json
└── security-scan.json

# Metrics Dashboard

Key Metrics:

Test pass/fail rates over time
Coverage trends
Performance regression indicators
Security vulnerability counts

Integration:

GitHub Actions status checks
Codecov coverage tracking
Slack notifications for failures
Email reports for weekly summaries

This comprehensive testing strategy ensures robust, secure, and performant code delivery for the pandemic surveillance platform.

# Testing Strategy Documentation

# Overview

# Testing Pyramid

# Test Categories

# 1. Unit Tests

# 2. Integration Tests

# 3. Security Tests

# 4. Performance Tests

# Test Organization

# Directory Structure

# Test Configuration

# Jest Configuration (jest.config.js)

# Test Data Management

# Mock Data Strategy

# Database Testing

# Continuous Integration Testing

# Pipeline Integration

# Parallel Test Execution

# Test Quality Metrics

# Coverage Metrics

# Quality Gates

# Performance Testing

# Load Testing Strategy

# Performance Test Implementation

# Security Testing

# Authentication Testing

# Input Validation Testing

# Test Maintenance

# Regular Maintenance Tasks

# Test Debugging

# Best Practices

# Test Writing Guidelines

# Mock Management

# Error Testing

# Reporting and Analytics

# Test Reports

# Metrics Dashboard

# Jest Configuration (`jest.config.js`)