annizhang / fetch-exercise

Fetch Rewards Exercise

Requirements

go 1.17.6

How to Run

$ go build
$ ./fetch-exercise

Starting server at port 8080

Implemented Endpoints:

Add Transactions

Add transaction for specific payer, transaction amount, and date

• URL

  /add_transaction

• Method

  POST

• Request Body

  • payer string
  • points int
  • timestamp string

• Success Response

  • Code: 201

Spend Points

Spend points using oldest payer points first and returns which points were spent from which payer

• URL

  /spend_points

• Method

  POST

• Request Body

  • points int

• Success Response

  • Code: 200
  • Content:

    {
    "spent_points": [
      {
        "payer": "DANNON",
        "points": -100
      },
      {
        "payer": "UNILEVER",
        "points": -200
      },
      {
        "payer": "MILLER COORS",
        "points": -4700
      }
    ]
  }
  

• Error Response

  • 400 Bad Request

Get Points

Get Points returns total payer points

• URL

  /get_points

• Method

  GET

• Success Response

  • Code: 200
  • Content:

  {
    "points": {
      "DANNON": 1000,
      "MILLER COORS": 5300,
      "UNILEVER": 0
    }
  }
  

Example Calls

First add transactions

Requests:

curl -H "Content-Type: application/json" -X POST -d '{ "payer": "DANNON", "points": 1000, "timestamp": "2020-11-02T14:00:00Z" }' http://localhost:8080/add_transaction

curl -H "Content-Type: application/json" -X POST -d '{ "payer": "UNILEVER", "points": 200, "timestamp": "2020-10-31T11:00:00Z" }' http://localhost:8080/add_transaction

curl -H "Content-Type: application/json" -X POST -d '{ "payer": "DANNON", "points": -200, "timestamp": "2020-10-31T15:00:00Z" }' http://localhost:8080/add_transaction

curl -H "Content-Type: application/json" -X POST -d '{ "payer": "MILLER COORS", "points": 10000, "timestamp": "2020-11-01T14:00:00Z" }' http://localhost:8080/add_transaction

curl -H "Content-Type: application/json" -X POST -d '{ "payer": "DANNON", "points": 300, "timestamp": "2020-10-31T10:00:00Z" }' http://localhost:8080/add_transaction

Response:

{"message":"201 Created"}
{"message":"201 Created"}
{"message":"201 Created"}
{"message":"201 Created"}
{"message":"201 Created"}

Spend points

Request:

curl -H "Content-Type: application/json" -X POST -d '{ "points": 5000 }' http://localhost:8080/spend_points

Response:

{
  "spent_points": [
    {
      "payer": "DANNON",
      "points": -100
    },
    {
      "payer": "UNILEVER",
      "points": -200
    },
    {
      "payer": "MILLER COORS",
      "points": -4700
    }
  ]
}

Get points

Request:

curl -H "Content-Type: application/json" http://localhost:8080/points

Response:

{
  "points": {
    "DANNON": 1000,
    "MILLER COORS": 5300,
    "UNILEVER": 0
  }
}

Notes for Improvement

• Add unit tests
• Handle more validation and errors
• Wrap responses with status codes and messages
• Add persistent storage