Payment Transaction

Payment transaction is a Restful API written in Golang, which simulates a purchase made with card and according to certain rules, approve or not approve the financial transaction.

Install

To run this program, you will need to:

$ export GOPATH=$(go env GOPATH)
$ go get github.com/vinixavier/payment_transaction
$ cd $GOPATH/vinixavier/payment_transaction
$ go install
$ $GOPATH/bin/payment_transaction &

Once this is done, the program will listen on localhost:3000.

Test

To test this program:

$ cd $GOPATH/github.com/vinixavier/payment_transaction
$ go test

Using

To make a payment, use the curl command or the postman application to perform a POST for the API.

Example in Linux with the curl command:

$ curl -X POST -d @examples/input.json http://localhost:3000/payment

{"approved":false,"deniedReasons":["Card is blocked!"]}

See examples of request files in the examples/*.json directory.

Payment

POST /payment

Make a payment.

Request

{
    "account": {
        "cardIsActive": "Boolean",
        "limit": "Number",
        "blacklist": [ "String" ],
        "isWhitelisted": "Boolean"
    },
    "transaction": {
        "merchant": "String",
        "amount": "Number",
        "time": "String"
    },
    "lastTransaction":
        [ "<Transaction>" ]
    }
}

Response

{
  "approved": "Boolean",
  "newLimit": "Number",
  "deniedReasons": [ "String" ]
}

Payment Rules

This API considers the following rules to be applied at the time of the transaction:

1. The transaction amount should not be above limit.
2. No transaction should be approved when the card is blocked.
3. The first transaction shouldn't be above 90% of the limit.
4. There should not be more than 10 transactions on the same merchant.
5. Merchant blacklist.
6. There should not be more than 3 transactions on a 2 minutes interval

To Do

1. Include application/json header.
2. Include more unit tests.