paytest: A Scala repository from rephus

This REST api powered by Spray and persistence on Slick allows users to create, update and list payments and accounts.

Libraries and frameworks:

Scala 2.11.8
Spray: REST api
Slick: Persistence
Postgres/H2: Database drivers
Flyway: To run DB migrations
Specs2: Testing framework

Endpoints

GET /payment list all papyments
GET /payment/[id] get payment by id
POST /payment create new payment
PUT /payment/[id] update an existing payment
DELETE /payment/[id]

Extra endpoints for monitoring, useful when implementing a complex microservice stack:

GET / return status and name of the app
GET /ping pong

Features

Database migrations using slick
Payment endpoint
Status endpoint
Postgres database on docker when running server, but H2 database for tests
Added pagination (limit, from filters) on list of payments endpoint
Comprehensive test coverage on tests, DB methods, API and serializers

Project structure

This is the structure of the modules in the project, it follows the model-view-controller pattern.

src/main/resources/db : Folder with all migrations tu run with Flyway
src/main/resources/application.conf: Configuration file for the server
src/main/scala/paytest: Where the code of the app is
- Boot: App entrypoint, we run DB migrations and initialize the Spray REST API service
- controller: contains the endpoints, and their actions, response serialization happens implicitly
- model: contains the classes and the DB mapping
- view: contains the JSON serializers
- service: contains the DB acctions (insert, select, update, delete...)

All tests are inside src/test/scala/paytest, following a similar model-view-controller structure. There is also another application.conf file with the H2 database details only for tests. Plus, there is an additional factory pakcage for generating random objects (Account and Payment) with filled fields

Implementation comments

This is the list of this that I did or didn't do, most of them don't provide any value to the showcase of this project, but they are used to simplify the implementation.

DB in postgres "paytest" is created on startup with the init.sql script on docker
I'm using string instead of uuid db types to avoid library conflicts, simplify tests and database compatibilities
I'm generating randomStrings and randomFloats on every field on data and tests that are required, in order to avoid hardcoded false positives and import data faster
jsonapi was not implemented as I undrestand this is a matter of updating the format accordingly and doesn't provide any value for this test
There is no endpoint to create, list or update accounts. If needed, only a new controller needs to be created.

Things to do next

This is a list of this that should be done before moving to a full environment.

Add security to API (uses profiles, access token, private network...)
Filter payment results on queryparams
Version API
Add error reporting system (eg: Sentry)
Add swagger and external documentation on API
continuous integration / continuous deploy

Testing

Run all test

./sbt test

Run a particular test (regex)

./sbt 'test-only *Serializer*'

Or use docker instead

docker-compose run paytest bash -c "./sbt test"

Run the server

Before running the server, you will need to be running a postgres instance with a paytest database, you can run it on your machine using docker with

docker-compose up postgres

Run with docker

docker-compose up paytest

Or use the already built java jar (sbt assembly)

java -jar server.jar

You could also use ./sbt run but you need to change the application.conf to use postgres on localhost

Sample usage: create a payment

PK id UUID is generated automatically

curl -X POST http://localhost:8655/payment -H "Content-Type: application/json" -d'{
  "reference":"",
  "sender_charges":[
    {"amount":0.3476658,"currency":"EUR"},
    {"amount":0.5503485,"currency":"GBP"}
  ],
  "sponsor":null,
  "numeric_reference":833901495,
  "fx":{
    "contract_reference":"ZYvTBee",
    "exchange_rate":0.9312809109687805,
    "original_currency":"YDVf13O1",
    "original_amount":0.8121793270111084
  },
  "debtor":null,
  "amount":0.647894024848938,
  "scheme_payment_subtype":"",
  "id":"6218ace4-cb59-4a27-8733-4806962ac944",
  "payment_type":"z2XSji",
  "payment_id":-263217557,
  "receiver_charges_amount":0.5060580968856812,
  "scheme_payment_type":"m",
  "bearer_code":"",
  "debtor_id":"2",
  "currency":"GBP",
  "beneficiary":null,
  "beneficiary_id":"1",
  "payment_purpose":"EEpwK",
  "sponsor_id":"3",
  "end_to_end_reference":"pT7GOpWK0",
  "receiver_charges_currency":"USD",
  "payment_scheme":"83Cil",
  "processing_date":"2018-01-01"}
'

rephus/paytest