credit-api

Requirements

The following must be installed on the host machine:

• docker
• docker-compose
• make

Usage

Building Images

make build

• builds the necessary images defined in the docker-compose.yaml file

Running Unit Tests

make test_unit

• runs all tests in the tests/unit folder

Running API

make run

• if not already running, starts up the postgres container
• applies migrations in the /migrations/versions folder to the postgres instance using alembic
• starts the api (api will be running on localhost:5001)

Running Functional Tests

(while API is running in separate terminal) make test_functional

• runs all tests in the tests/functional folder

API Specification

While running, the API can be hit on the host machine using localhost:5001

Full swagger API specification can be retrieved from localhost:5001/swagger.json

All numeric values (credit, payment amount, withdrawal, etc...) must be represented in microdollars. 1c = 1000000 microdollars. The values are stored and calculated in microdollars. This helps to prevent rounding errors when calculating in currencies.

Testing

To test the endpoints manually, you can do the following:

1. Create a new customer and save its uuid
2. Create a new account with that customer uuid
3. Apply payments/withdrawals to that account using the account uuid. Specify different dates to simulate real user activity.
4. Check the account responses to ensure their accuracy

Endpoints

/customer [POST]

• Creates a new customer and returns it back for confirmation.

Payload

{
    "fname": <Customer first name>,
    "lname": <Customer last name>,
    "email": <Customer email>
}

Response

{
    "uuid": <Customer uuid>,
    "fname": <Customer first name>,
    "lname": <Customer last name>,
    "email": <Customer email>
}

/customer/<uuid> [GET]

• <uuid> must be an existing customer id.
• Attempting to access a non-existing customer will return a 404.

Response:

{
    "uuid": <Customer uuid>,
    "fname": <Customer first name>,
    "lname": <Customer last name>,
    "email": <Customer email>
}

/account [POST]

• Creates a new account and returns it back for confirmation.
• All numeric values should be sent/received in microdollars

Payload

{
    "customerUUID": <The customer's UUID>,
    "maxCredit": <Maximum Credit for this account>,
    "timeOpened": <The time the account was opened>,
    "apr": <The apr for this credit line>
}

Response

{
    "uuid": <The account uuid>,
    "apr": <The account apr>,
    "maxCredit": <The maximum credit for this account>,
    "timeOpened": <The time the account was opened>,
    "availableCredit": <The amount of credit left on the account>,
    "principalOwed": <The amount of principal owed on the account>,
    "interestOwed": <The amount of interest owed on the account>
}

/account/<uuid>?time=<time>

• <uuid> is the account uuid
• <time> gets the account information as of a certain time. Defaults to now()
• Attempting to access a non-existing account will return a 404.

Response

{
    "uuid": <The account uuid>,
    "apr": <The account apr>,
    "maxCredit": <The maximum credit for this account>,
    "timeOpened": <The time the account was opened>,
    "availableCredit": <The amount of credit left on the account>,
    "principalOwed": <The amount of principal owed on the account>,
    "interestOwed": <The amount of interest owed on the account>
}

/account/payment [POST]

• Applies the payment then returns the updated balance information.
• Invalid payments will return a 422 error code.

Payload

{
    "accountUUID": <The account uuid>,
    "time": <The time the payment took place (default now())>,
    "amount": <The amount of the payment in microdollars>
}

Response

{
    "uuid": <The account uuid>,
    "apr": <The account apr>,
    "maxCredit": <The maximum credit for this account>,
    "timeOpened": <The time the account was opened>,
    "availableCredit": <The amount of credit left on the account>,
    "principalOwed": <The amount of principal owed on the account>,
    "interestOwed": <The amount of interest owed on the account>
}

/account/withdrawal [POST]

• Applies the withdrawal then returns the updated balance information.
• Invalid withdrawals will return a 422 error code.

Payload

{
    "accountUUID": <The account uuid>,
    "time": <The time the withdrawal took place (default now())>,
    "amount": <The amount of the withdrawal in microdollars>
}

Response

{
    "uuid": <The account uuid>,
    "apr": <The account apr>,
    "maxCredit": <The maximum credit for this account>,
    "timeOpened": <The time the account was opened>,
    "availableCredit": <The amount of credit left on the account>,
    "principalOwed": <The amount of principal owed on the account>,
    "interestOwed": <The amount of interest owed on the account>
}