Weather App

Project Overview

This Node.js application uses TypeScript to interact with a weather API and fetch temperature data based on user-provided date and location parameters. It handles API rate limits, data formatting, and ensures data persistence using SQLite for caching.

Requirements

• Node.js
• Docker
• SQLite

Setup and Run

1. Clone the repository:

   git clone <repository_url>
   cd weather-app

2. Install dependencies:

   npm install

3. Build the application:

   npm run build

4. Run the application:

   npm start

5. Run tests:

   npm test

Docker

To run the application using Docker:

1. Build the Docker image:

   docker build -t weather-app .

2. Run the Docker container:

   docker run -p 3000:3000 weather-app

API Endpoint

• GET /weather?city=<city>&date=<date>
  • Parameters:
    • city: The city for which to fetch the weather data.
    • date: The date for which to fetch the weather data (in ISO 8601 format).
  • Example:

    http://localhost:3000/weather?city=London&date=2024-07-20
    

Approach

Caching

• SQLite: Used SQLite to cache weather data to avoid hitting the API rate limit. Cached data expires appropriately to ensure freshness.
• Initialization: The database and table are created if they do not exist.

Error Handling

• API Limits: Implemented robust error handling for API rate limits, random errors, and data format issues.
• Retries: Retries on transient errors to handle temporary issues with the API.

Testing

• Jest: Comprehensive tests for API integration, data conversion, caching mechanism, and error handling using Jest.
• Coverage: Ensures that the application works as expected and handles edge cases.

Assumptions

• The weather API endpoint and documentation are accurate and reliable.
• The cache expiration is handled within the scope of this task, and no external cache expiration policy is applied.

Environment Variables

• PORT: The port on which the application will run (default is 3000).

Additional Notes

• Ensure SQLite is installed and accessible in your environment.
• Ensure that the .env file is properly configured with the required environment variables if any.

Example Response

{
  "city": "London",
  "date": "2024-07-20",
  "temperatureCelsius": 20,
  "temperatureFahrenheit": 68
}

Directory Structure

weather-app/
├── src/
│   ├── index.ts
│   ├── server.ts
│   ├── weatherService.ts
│   ├── cache.ts
│   ├── types.ts
│   ├── utils.ts
├── tests/
│   ├── weatherService.test.ts
│   ├── cache.test.ts
├── .env
├── Dockerfile
├── jest.config.js
├── package.json
├── README.md
├── tsconfig.json