Flights aggregator

This is the coding challenge for PowerUs Fullstack developer position

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Requirements:

• Your service should get flights from these 2 routes, merge them, remove duplicates, and send them to the client. https://coding-challenge.powerus.de/flight/source1 https://coding-challenge.powerus.de/flight/source2
• As the identifier of the flight, the combination of flight numbers and dates can be used.
• The flight services above are not stable, i.e. it can sometimes fail or reply after a couple of seconds.
• The response time of your service shouldn't take longer than 1 second.
• Please write tests for your implementation.

Details:

• Think that this service will be used in a flight search page for the customers.
• There will be many other flight source services added in the future.
• We can assume any information that we get from the endpoints remains valid for an hour.
• It is always better to show more results to the end-user as much as possible, but never invalid information.

Expectations:

• Clean code, easy to read
• Scalability
• Simplicity
• Using NestJS as a framework and Jest for testing is a plus.

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Notes

Technologies:

• TypeScript
• NestJS
• Prisma
• Jest
• Swagger
• MongoDB
• Docker - docker-compose

Requirements:

• Development requirements: node.js version 19 and MongoDB. It is required by Prisma to have MongoDB replicaset configured. If you don't have it configured locally (or in Docker) then I would suggest to use Mongo Atlas service, it's free (for study usage) and easy in setup (*I'll send the DB credentials in email).

• Local run requirements: requirements are the same as for development, or you can run it in docker (required to install Docker and docker-compose)

Configuration:

The project configuration is based on ENV file. Just copy (and edit) the .env.example file and save it as .env.

If you're going to run it in docker, then copy (and edit) the .env.docker.example file to .docker/app/.env.docker.

You can also specify which .env file to read via setting the file path in ENV_FILE_PATH evn variable.

There also is config file for specifying flights providers - flights-providers-config.yaml.

Run:

The application has two scopes: api and tasks.

api scope responsible for the API application only, and tasks for tasks scheduler with tasks only.

api application scope doesn't fetch providers flights, the flights endpoint just shows data from the DB. In order to fetch data from flights providers you need to start app with scope tasks.

To select application scope you should set APP_SCOPE env variable in the .env file.

So, normally running application consists of two instances (one for api and another for tasks).

• Development: run npm run start:dev this command will start the development server with hot reload.
• Docker: run docker-compose build and then docker-compose up -d (run docker-compose down if you would like to stop the project). This will build and run the project with Redis cache.
• Tests: run npm run test.

Development:

• Project has plop generation, so if you need to add a new controller or provider just use plop and it will generate it in the right place with the right structure.
• All the API response body keys are converted to snake_case via snake-case.interceptor.ts, so you can write your controller DTO properties in camelCase. Also take a look at @SCApiProperty decorator - it will help to convert your swagger API response body keys to snake_case.
• Use fast-case lib for your case conversions.