Contents

1. Introduction
2. Building
3. Running the server
4. Running the client
5. Generating Swagger

Introduction

This repository contains a simple example of how to use the servant-checked-exceptions library.

The example has a simple API, representing a simple database of locations, where each location has a unique integer ID and a unique name.

The API provides operations to add new locations, as well as to find existing locations based on ther IDs or names.

Each endpoint is capable of throwing exceptions, as declared with the Throws combinator. Each exception type corresponds to a specific HTTP error code.

Building

$ stack build

Running the server

$ stack exec server

Running the client

Adding locations

$ stack exec client -- addLocation "Cambridge"
Location {locationId = 0, locationName = "Cambridge"}

$ stack exec client -- addLocation "Oxford"
Location {locationId = 1, locationName = "Oxford"}

$ stack exec client -- addLocation "Boston"
Location {locationId = 2, locationName = "Boston"}

$ stack exec client -- addLocation "Taipei"
Location {locationId = 3, locationName = "Taipei"}

Adding locations (unsuccessfully, triggering exceptions)

$ stack exec client -- addLocation "A"
LocationNameTooShortError

$ stack exec client -- addLocation "****"
LocationNameHasInvalidCharsError

Finding locations

$ stack exec client -- findLocationById 0
Location {locationId = 0, locationName = "Cambridge"}

$ stack exec client -- findLocationByName Oxford
Location {locationId = 1, locationName = "Oxford"}

Finding locations (unsuccessfully, triggering exceptions)

$ stack exec client -- findLocationById 1000
NoMatchingLocationError

$ stack exec client -- findLocationByName Utopia
NoMatchingLocationError

Generating Swagger

$ stack exec swagger | json_pp | less