What are the main steps to start contract testing?

1. Contract Definition: Identifying agreements between services and their formal description (OpenAPI/Swagger, AsyncAPI, Protocol Buffers).
2. Creating Test Data: Preparing data sets that conform to the contract specification for each scenario.
3. Tool Selection: Choosing the appropriate tool for contract testing (Pact, ReadyAPI, Postman with Newman).
4. Writing Tests: Implementing test cases on the selected tool to verify contract compliance.
5. Running Tests: Executing tests in a test environment.
6. Analyzing Results: Reviewing testing reports, identifying discrepancies and errors in contracts or their implementation.
7. CI/CD Integration: Automating contract tests at each stage of the development pipeline.

# Example of simple contract check using requests
import requests
import json

def test_api_contract():
    url = "http://api.example.com/users"
    response = requests.get(url)

    assert response.status_code == 200  # Check status code

    data = response.json()
    assert isinstance(data, list)  # Check that the response is a list

    if data:
        user = data[0]
        assert "id" in user
        assert isinstance(user["id"], int)
        assert "name" in user
        assert isinstance(user["name"], str)