Add Unit, Integration, and E2E Tests with GitHub Actions CI Workflow

[rimanshu-SF]

📦 Overview

This PR introduces a complete testing and CI setup for the Book Management System (BMS) microservices architecture, including:

• ✅ Unit tests for isolated components
• ✅ Integration tests to validate inter-module communication
• ✅ End-to-End (E2E) tests via the API Gateway
• ✅ GitHub Actions CI pipeline to run all tests on every commit/PR

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🧪 Testing Strategy

• Unit Tests:

  • Each microservice contains its own unit tests using Mocha, Chai, and LoopBack 4's testing utilities.

• Integration Tests:

  • Validate service-level operations (e.g., creating a book with a valid author/category).
  • Ensure services interact correctly with their repositories and controllers.

• E2E Tests (API Gateway):

  • Simulate full user flow: create author, category, book via the gateway.
  • Uses supertest with mock JWT tokens for protected routes.

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⚙️ GitHub Actions

• A new workflow (.github/workflows/e2e.yml) is added to:
  • Clone all microservices
  • Install dependencies
  • Start services in the background
  • Run E2E tests through the API Gateway

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📌 Notes

• Microservices are maintained in separate repositories.
• All services assumed to run on separate ports.
• DB interactions are mocked or use in-memory DBs.
• Secrets and private repo tokens should be configured for full CI coverage.

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✅ Checklist

• Unit tests added
• Integration tests added
• E2E tests implemented via gateway
• GitHub Actions workflow tested and passing