JustGiving Test

Dev Summary

The solution is written in .NetCore 3 with the shared code using .NetStandard 2. The data store is a SQLlite DB using Entity Framework. Swagger is the API Client used to document the API and is exposed when running the API to provide support in testing the API. XUnit is the testing framework used for Unit Tests.

API Endpoints

• GiftAid - /api/giftaid
• Donation - /api/donate
• Test - /api/test

Improvements to be made:

• The unit tests are basic and need to be improved
• Add API Application Metrics
• Add docker containerization support
• Add application logging

Instructions

A big part of what we do at JustGiving is reclaim the Gift Aid on donations made to charities. This saves them a lot of time and processing overheads.

The calculation for gift aid is [Donation Amount] * ( [TaxRate] / (100 - [TaxRate]) ).

• For unit testing we use NUnit and NSubstitute, these are already referenced in the projects, but feel free to use which ever framework you prefer.
• All stories should be completed with an appropriate amount of testing.
• Please create a public repo (GitHub, BitBucket, GitLab etc) and send us the link, make sure to commit regularly so we can see how you came up with the solution.
• Remember to be RESTful.

Story 1 - Gift Aid Calculator

• Create a calculator.
• Gift aid calculated at a tax rate of 20%.

Story 2 - Endpoint

• Create an endpoint so that other services can access the calculation for Gift Aid.
• Use this swagger spec as the basis for your API

swagger: '2.0'
info:
  title: Gift Aid Service
  version: 1.0.0
basePath: /api
schemes:
  - https
paths:
  /giftaid:
    get:
      summary: Get the amount of gift aid reclaimable for donation amount
      parameters:
        - in: query
          name: amount
          type: number
          required: true
      produces:
        - application/json
      responses:
        '200':
          description: OK
          schema:
            $ref: '#/definitions/GiftAidResponse'
definitions:
  GiftAidResponse:
    type: object
    required:
      - donationAmount
      - giftAidAmount
    properties:
      donationAmount:
        type: number
      giftAidAmount: 
        type: number

Story 3 - Validation

• There are two validation rules:
  • Minimum donation amount is £2.00.
  • Maximum donation amount is £100,000.00.
• Add validation for these cases and any other validation / error handling you think is appropriate for this endpoint.
• Add appropriate tests and document the endpoint

Story 4 - Storing Gift Aid Declarations

• When a user makes a donation with Gift Aid, we need to store information about the donor.
• We need to store:
  • Name
  • Post Code
  • Donation Amount
• Add an endpoint for this.
• Mock a database or add a simple in-memory database (maybe LiteDB) to persist this data.
• Produce a unique id for the declaration.
• Return the declaration id and the gift aid amount in the reponse.
• Add appropriate tests and document the endpoint

Thanks for your time, we look forward to hearing from you!