Dave's Tech Test

Running the app

To start the app run make currencyFair-run (Requires docker)

I developed on Ubuntu but it should all work on Mac. If there's an error running that command let me know.

To run tests make run-tests

Tools used

Backend: Laravel, PHP 7.4, Docker, Postgres

Frontend: React, TypeScript, SASS (FE code is in /frontend-app dir)

Approach

While this API consists of just two endpoints, I approached the task as if I were building the foundations of a large API.

• Instead of traditional controllers I went with single action controllers. I find as an API grows over time this keeps the code base clean and you don't end up with monster controllers. They are also easier to test.
• DB access is via repositories which return DomainObjects, making it easy to swap in elasticSearch or another data store seamlessly.
• Service classes all have just one public 'execute' method. Again, easy to test and adheres to the SRP.
• All validation is done in custom requests so no validation logic in controllers or services. Each entity has its own validator which is easily reusable.
• Everything is Dockerised so setup 'should' be simple

What I'd change with more time / What I didn't do

• Currently the FE is polling the API, this should be using websockets
• It would have been nice to use a time-series DB like TimeseriesDb or InfluxDB
• The FE has no tests
• Adding visualisation
• The FE UI isn't responsive
• I hackily 0777 some dirs in the setup as I didn't have time to debug docker

cURL requests

Create a transaction

curl -X POST \
  http://127.0.0.1:2591/api/transactions \
  -H 'accept: application/json' \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/json' \
  -d '{"userId": "134256", "currencyFrom": "USD", "currencyTo": "GBP", "amountSell": 2222.45, "amountBuy": 200.10, "rate": 0.7471, "timePlaced" : "24-JAN-18 10:27:44", "originatingCountry" : "FR"} '

Get all transactions

curl -X GET \
  http://127.0.0.1:2591/api/transactions \
  -H 'accept: application/json' \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/json' \

Any questions let me know :-)

Cheers!