Simple Haskell "Real world app"

A "simple Haskell" web app in order to show how Haskell shines at building "standard" apps with industrial practices (tdd & bdd).

It aims to implement the real world app API

Main 3rd party libraries

Following the Port & Adapter architecture, the frameworks can be replaced with one another. To illustrate this, the app let you choose between 2 http servers and 2 storage backends at startup (see below), they also pass the same test suite.

• HTTP routers : Scotty & Servant
• Persistence : Hasql & Tvar (business logic tests)
• Logs : Katip & Tvar (business logic tests)
• Testing : Hspec

start the App

open a shell with all the needed deps (using nix-shell)

nix-shell

make start-pg
make run

or the using docker (requires no local system dependency)

make run-docker

app configuration

var	default	type	description
SERVER	servant	servant | scotty	the http server implementation
PORT	3000	Int	the port the server will listen on
STORAGE	hasql	hasql|inMem	the storage implementation
DB_HOST	localhost	String	(hasql): the db host
DB_PORT	5432	Int	(hasql): the db port
DB_USER	postgres	String	(hasql): the db user
DB_PASSWORD	password	String	(hasql): the db password
DB_NAME	postgres	String	(hasql): the db name

curl -v localhost:3000/api/users -d '{"user": {"email": "bla", "username": "bob", "password": "hello"}}' -H 'content-type:application/json'