contractpy 0.1.3

A tiny library for validating our data if its adhere the contract.

contractpy

contractpy is a tiny library for validating our data against a contract.

Basic usage

You could simply create a contract object and you could validate your data against the contract.

from pycontract import Contract, Types

my_contract = {
    'name': Types.STRING,
    'id': Types:INTEGER
}
contract = Contract(my_contract)

assert contract.verify({'name': 'Captain America': 'id': 12345}) is True

Yes it is as simple as this.

It works for complicated data as well. Like a json that contains a list of strings or list of dictionaries. It will recursively iterate over the inner dicts and check it against the contract. Please check out the other examples,

Other examples

my_contract = {
    'name': Types.STRING,
    'id': Types:INTEGER,
    'orders': [
        {
            'orderId': Types:INTEGER,
            'price': Types:FLOAT,
        }
    ],
    comments: [Types.String]
}

data = {
    'name': 'Hazel Grace',
    'id: 57331,
    'orders': [
        {
            'orderId': 1,
            'price': 420.45
        },
        {
            'orderId': 2,
            'price': 750.38
        }
    ],
    comments: ["I really liked the product!", "I am completely satisfied."]
}

assert Contract(my_contract).verify(data) is True

You could also do the contract testing for the APIs using this library. For Example,

    def test_users_api_conforms_the_contract(self):
        user_api_contract = {
            'page': Types.INTEGER,
            'per_page': Types.INTEGER,
            'total': Types.INTEGER,
            'total_pages': Types.INTEGER,
            'data': [
                {
                    'id': Types.INTEGER,
                    'name': Types.STRING,
                    'year': Types.INTEGER,
                    'color': Types.STRING,
                    'pantone_value': Types.STRING
                }
            ],
            'ad': {
                'company': Types.STRING,
                'url': Types.STRING,
                'text': Types.STRING
            }
        }

        response = requests.get('https://reqres.in/api/user?page=1')

        assert response.status_code == 200
        assert Contract(user_api_contract).verify(response.json()) is True

Note: Here, the test api is powered by reqres.in