Welcome to Authorizer

This Project was created with the objective to carry out banking transactions following the rules proposed by the bank instituition.

🏦

How to Run 🎡

Preparing the environment 💻

How is nothing too complex the environment is more prepared for perform tests

Execute: (os & Linux)

1 - virtualenv .venv

2 - source .venv/bin/activate

(Windows)

1 - python -m venv .venv

2 - source .venv/Scripts/activate

3 - pip install -r requirements.txt

To execute the project you must execute on the root project the follow command:

python3 authorizator.py < operations

To verify all the tests proposed you must:

access the tests/test.py and execute the run(pytest) with command: python3 -m unittest tests/test.py or use a framework (preference pycharm) here you you will have others scenarios

Explaining the project

infrastructure/Authorizer.py

This file is the first authorization layer, where the establishment/credit card machine have the freedom to know the status of client's credit card or know if is a valid credit card.

infrastructure/Account.py

Here is the core

This file is the account layer, here the app execute the process of captures from credit card errors for example: Limit to purchase, time for a request to another, duplicated purchase.

Businness rules:

1. No transaction should be accepted unless the account has been initialized: account-not-initialized.

2. No transaction should be accepted when the card is not active: card-not-active.

3. The transaction amount should not exceed the available limit: insufficient-limit.

4. There should be no more than 3 transactions from any merchant within a 2-minute interval: high-frequency-small-interval.

5. There should be no more than 1 similar transaction (same amount and merchant) within a 2-minute interval: double-transaction.

All the Scenarios is on tests/tmp_operations/operations_to_test.py

account-not-initialized

Request:

{"transaction": {"merchant": "Uber Eats", "amount": 25, "time": "2020-12-01T11:07:00.000Z"}}
{"account": {"active-card": true, "available-limit": 225}}
{"transaction": {"merchant": "Uber Eats", "amount": 25, "time": "2020-12-01T11:07:00.000Z"}}

Response:

operation: {"transaction": {"merchant": "Uber Eats", "amount": 25, "time": "2020-12-01T11:07:00.000Z"}}
operation_response: {'account': {}, 'violations': ['account-not-initialized']}

bank account: {'account': {'active-card': True, 'available-limit': 225}, 'violations': []}

operation: {"transaction": {"merchant": "Uber Eats", "amount": 25, "time": "2020-12-01T11:07:00.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 200}, 'violations': []}

card-not-active

Request:

{"account": {"active-card": false, "available-limit": 100}}
{"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
{"transaction": {"merchant": "Habbib's", "amount": 15, "time": "2019-02-13T11:15:00.000Z"}}

Response:

bank account: {'account': {'active-card': False, 'available-limit': 100}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
operation_response: {'account': {'active-card': False, 'available-limit': 100}, 'violations': ['card-not-active']}

operation: {"transaction": {"merchant": "Habbib's", "amount": 15, "time": "2019-02-13T11:15:00.000Z"}}
operation_response: {'account': {'active-card': False, 'available-limit': 100}, 'violations': ['card-not-active']}

insufficient-limit

Request:

{"account": {"active-card": true, "available-limit": 1000}}
{"transaction": {"merchant": "Vivara", "amount": 1250, "time": "2019-02-13T11:00:00.000Z"}}
{"transaction": {"merchant": "Samsung", "amount": 2500, "time": "2019-02-13T11:00:01.000Z"}}
{"transaction": {"merchant": "Nike", "amount": 800, "time": "2019-02-13T11:01:01.000Z"}}

Response:

bank account: {'account': {'active-card': True, 'available-limit': 1000}, 'violations': []}

operation: {"transaction": {"merchant": "Vivara", "amount": 1250, "time": "2019-02-13T11:00:00.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 1000}, 'violations': ['insufficient-limit']}

operation: {"transaction": {"merchant": "Samsung", "amount": 2500, "time": "2019-02-13T11:00:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 1000}, 'violations': ['insufficient-limit']}

operation: {"transaction": {"merchant": "Nike", "amount": 800, "time": "2019-02-13T11:01:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 200}, 'violations': []}

high-frequency-small-interval

Request:

{"account": {"active-card": true, "available-limit": 100}}
{"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
{"transaction": {"merchant": "Habbib's", "amount": 20, "time": "2019-02-13T11:00:01.000Z"}}
{"transaction": {"merchant": "McDonald's", "amount": 20, "time": "2019-02-13T11:01:01.000Z"}}
{"transaction": {"merchant": "Subway", "amount": 20, "time": "2019-02-13T11:01:31.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 10, "time": "2019-02-13T12:00:00.000Z"}}

Response:

bank account: {'account': {'active-card': True, 'available-limit': 100}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 80}, 'violations': []}

operation: {"transaction": {"merchant": "Habbib's", "amount": 20, "time": "2019-02-13T11:00:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 60}, 'violations': []}

operation: {"transaction": {"merchant": "McDonald's", "amount": 20, "time": "2019-02-13T11:01:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 40}, 'violations': []}

operation: {"transaction": {"merchant": "Subway", "amount": 20, "time": "2019-02-13T11:01:31.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 40}, 'violations': ['high-frequency-small-interval']}

operation: {"transaction": {"merchant": "Burger King", "amount": 10, "time": "2019-02-13T12:00:00.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 30}, 'violations': []}

doubled-transaction

Request:

{"account": {"active-card": true, "available-limit": 100}}
{"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
{"transaction": {"merchant": "McDonald's", "amount": 10, "time": "2019-02-13T11:00:01.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:02.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 15, "time": "2019-02-13T11:00:03.000Z"}}

Response:

bank account: {'account': {'active-card': True, 'available-limit': 100}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:00.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 80}, 'violations': []}

operation: {"transaction": {"merchant": "McDonald's", "amount": 10, "time": "2019-02-13T11:00:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 70}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:02.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 70}, 'violations': ['doubled-transaction']}

operation: {"transaction": {"merchant": "Burger King", "amount": 15, "time": "2019-02-13T11:00:03.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 55}, 'violations': []}

Multiple errors

Request:

{"account": {"active-card": true, "available-limit": 100}}
{"transaction": {"merchant": "McDonald's", "amount": 10, "time": "2019-02-13T11:00:01.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:02.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 5, "time": "2019-02-13T11:00:07.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 5, "time": "2019-02-13T11:00:08.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 150, "time": "2019-02-13T11:00:18.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 190, "time": "2019-02-13T11:00:22.000Z"}}
{"transaction": {"merchant": "Burger King", "amount": 15, "time": "2019-02-13T12:00:27.000Z"}}

Response:

bank account: {'account': {'active-card': True, 'available-limit': 100}, 'violations': []}

operation: {"transaction": {"merchant": "McDonald's", "amount": 10, "time": "2019-02-13T11:00:01.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 90}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 20, "time": "2019-02-13T11:00:02.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 70}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 5, "time": "2019-02-13T11:00:07.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 65}, 'violations': []}

operation: {"transaction": {"merchant": "Burger King", "amount": 5, "time": "2019-02-13T11:00:08.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 65}, 'violations': ['high-frequency-small-interval', 'doubled-transaction']}

operation: {"transaction": {"merchant": "Burger King", "amount": 150, "time": "2019-02-13T11:00:18.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 65}, 'violations': ['high-frequency-small-interval', 'insufficient-limit']}

operation: {"transaction": {"merchant": "Burger King", "amount": 190, "time": "2019-02-13T11:00:22.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 65}, 'violations': ['high-frequency-small-interval', 'insufficient-limit']}

operation: {"transaction": {"merchant": "Burger King", "amount": 15, "time": "2019-02-13T12:00:27.000Z"}}
operation_response: {'account': {'active-card': True, 'available-limit': 50}, 'violations': []}

infrastructure/ToolsAccount.py

This file it's like a helper for the Account, here has some tools and checkers for help the Account.