Flight Path Microservice

Overview

This microservice API sorts and tracks a person's flight path from unordered flight records. It accepts a list of flights defined by source and destination airport codes, sorts them, and finds the total flight path from starting to ending airports.

API Endpoint

URL

POST http://localhost:8080/calculate

Request Body

The request body should be a JSON object containing an array of flight segments. Each segment is an array with two elements: the source and destination airport codes.

Example:

{
  "flights": [
    ["IND", "EWR"],
    ["SFO", "ATL"],
    ["GSO", "IND"],
    ["ATL", "GSO"]
  ]
}

Response

The response will be a JSON object containing the ordered flight path from the starting airport to the ending airport.

Example:

{
  "path": ["SFO", "EWR"]
}

Error Responses

• 400 Bad Request: Invalid input

  {
    "error": "Invalid input: The request body must contain a \"flights\" array of arrays, where each sub-array represents a flight with a source and destination airport code. Example: { \"flights\": [[\"SFO\", \"EWR\"], [\"ATL\", \"EWR\"]] }"
  }

• 500 Internal Server Error:

  • No unique starting point

    {
      "error": "Invalid flight data: no unique starting point found."
    }

  • Cycle detected

    {
      "error": "Cycle detected in the flight path."
    }

  • Disjoint or unconnected flights

    {
      "error": "Invalid flight data: disjoint or unconnected flights detected."
    }

Setup Instructions

1. Clone the repository:

   git clone https://github.com/dattgoswami/flight-path-service
   cd flight-path-service

2. Install dependencies:

   npm install

3. Create .env file:

   touch .env
   echo "PORT=8080" >> .env

4. Start the server:

   npm start

5. Run in development mode:

   npm run dev

6. Run tests:

   npm test

7. Lint the code:

   npm run lint

Project Structure

Files and directories:

flight-path-service/
├── index.js 
├── controllers/
│   └── flightController.js
├── routes/
│   └── flightRoutes.js
├── middleware/
│   ├── errorHandler.js
│   └── logger.js
├── tests/
|   └── flightRoutes.test.js
├── .env //to be created from .env.example
├── server.log
├── package.json
└── README.md

Scaling / Hosting

• It can be hosted on AWS Lambda; provisioned concurrency can be used to pre-initialize execution environments to respond to incoming requests meediately(i.e. reducing cold starts)
• With a trigger from API Gateway set on this Lambda
• It can be made asynchronous by decoupling the API Gateway and Lambda using AWS SQS(queue) in between

Tests

The following 10 test cases validate the calculateFlightPath function thoroughly:

1. Valid flight path:

   • Confirms the correct ordering of a simple set of flights.

2. Valid flight path with multiple segments:

   • Ensures the function handles longer flight paths correctly.

3. No unique starting point:

   • Detects when there is no unique starting point in the flight data.

4. Single flight:

   • Handles a case with only one flight segment.

5. Empty input:

   • Handles empty flight data gracefully.

6. Invalid input (not an array):

   • Ensures the input must be an array of flight segments.

7. Invalid input (malformed flight data):

   • Validates the structure of each flight segment.

8. Unconnected flight:

   • Detects if there are any unconnected flights.

9. Disjoint flights:

   • Identifies when flights are not connected to form a single path.

10. Cycle detected:

    • Checks for cycles in the flight path.

Summary

The Flight Path Microservice efficiently handles unordered flight records to provide a sorted flight path. By following the setup instructions and utilizing the error handling, the service ensures robust performance and accurate results.