Project Description

Overview

This project is a backend server application built with Node.js and Express. It is designed to handle HTTP requests, log activities, secure the application, and manage API rate limiting, generic error handler middleware and generic async handler for the routes controllers. The server also supports multi-core systems by utilizing clustering to run multiple instances.

Requirements

Node Js v20.9.0

Project Structure

• Root Directory

  • index.js: Main entry point that tests the express application.
  • package.json: Contains project metadata and dependencies.
  • .env: Environment variables configuration file.
  • all-cities.json: JSON file containing city data.
  • README.md: Project documentation.
  • jest.config.js: Configuration file for Jest testing framework.
  • coverage: Directory containing code coverage reports.
  • __tests__: Directory containing test files.

• server/

  • index.js: Initializes and configures the Express application.
  • addresses.json: JSON file containing address data.
  • routes/
    • cities.js: Defines routes related to city data.
  • util/
    • util.js: Utility functions used across the application.

Key Features

• Express Server: Handles HTTP requests and responses.
• Middleware:
  • helmet: Secures the app by setting various HTTP headers.
  • morgan: Logs HTTP requests.
  • express-rate-limit: Limits repeated requests to public APIs.
  • cors: Enables Cross-Origin Resource Sharing.
• Clustering: Utilizes multiple CPU cores to improve performance.
• Environment Configuration: Uses .env file for environment-specific settings.
• Testing: Configured with Jest and Supertest for unit and integration testing.

Setup Instructions

1. Install Dependencies:

   npm install

2. Run Tests:

npm run test

3. Start the Express Server:

npm run start-express

4. Build and Run the Docker Container:

Build the Docker image: docker build -t gan-integrity-backend . Run the Docker container: docker run -p 8080:8080 gan-integrity-backend

Dependencies

• [express]: Web framework for Node.js.
• [cors]: Middleware for enabling CORS.
• dotenv: Loads environment variables from a .env file.
• [express-rate-limit]: Middleware to limit repeated requests.
• [express-validator]: Middleware for validating and sanitizing requests.
• fs-extra: Provides additional file system methods.
• [helmet]: Helps secure Express apps by setting various HTTP headers.
• [morgan]: HTTP request logger middleware.
• node-fetch: A light-weight module that brings window.fetch to Node.js.

DevDependencies

• jest: JavaScript testing framework.
• supertest: HTTP assertions made easy via superagent.

GAN Integrity backend code challenge

The script index.js uses a local api to perform various operations on a set of cities. Your task is to implement an api so that the script runs successfully all the way to the end.

Run npm install and npm run start to start the script.

Your api can load the required data from here.

In the distance calculations you can assume the earth is a perfect sphere and has a radius is 6371 km.

Once you are done, please provide us with a link to a git repo with your code, ready to run.