Add comprehensive Python test suite for .NET mail service conversion

[Copilot]

Created complete test infrastructure for Python conversion with 116 test cases targeting 90%+ coverage across models, commands, services, and APIs. Includes WCAG 2.1 Level AA accessibility validation.

Test Suite Structure (1,810 LOC)

Unit Tests

• Models: Contact validation, email parsing, broadcast scheduling (22 tests)
• Commands: Signup flow, duplicate handling, transaction management (18 tests)
• Services: SMTP sending, retry logic, background processing (12 tests)
• API: Public endpoints, validation, error handling (20 tests)

Integration Tests

• Database: Connection pooling, transactions, CRUD operations (10 tests)
• Accessibility: Keyboard navigation, screen readers, contrast ratios, ARIA compliance (24 tests)
• End-to-end workflows: Signup, email sending, unsubscribe flows

Infrastructure

# tests/conftest.py - Shared fixtures
@pytest.fixture
def sample_contact():
    return {
        'name': 'John Doe',
        'email': '[email protected]',
        'subscribed': True,
        'key': 'test-key-123'
    }

# tests/models/test_contact.py - Example test
def test_contact_email_validation_invalid(self):
    invalid_emails = ['invalid.email', '@example.com', 'user@']
    for email in invalid_emails:
        with pytest.raises(ValueError):
            Contact(name="Test User", email=email)

Configuration

• pytest.ini: Coverage thresholds, test discovery, markers
• Makefile: test, test-coverage, test-accessibility, lint, security
• GitHub Actions: Multi-version Python (3.9-3.12), coverage reporting, security scans

Dependencies

• Testing: pytest, pytest-cov, pytest-asyncio, pytest-mock, pytest-xdist
• Quality: flake8, pylint, black, mypy, isort
• Security: bandit, safety
• Accessibility: axe-selenium-python, pa11y

Coverage Targets

Component	Tests	Target
Models	22	95%
Commands	18	95%
Services	12	90%
API Routes	20	90%
Integration	44	85%

Documentation

• README.md: Project overview, setup, API documentation
• TESTING_GUIDE.md: TDD practices, test patterns, debugging
• TEST_COVERAGE.md: WCAG compliance checklist, security requirements
• PYTHON_TESTS_SUMMARY.md: Complete implementation summary

Tests are ready to validate Python implementation once conversion is complete. All fixtures, mocks, and test data structures mirror .NET service behavior.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Convert into Python</issue_title>
<issue_description>- Convert this code into python using best practices

• Add full coverage unit tests in python
• I want the UI to be accessible</issue_description>

<agent_instructions>create tests</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Convert into Python #24

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To fix the problem, explicitly add a permissions block to the workflow. Since all jobs in the workflow only read repository contents (e.g., for checking out code and running tests) and do not require write privileges (such as writing to the repository, creating/forking pull requests, or pushing changes), set the permission to the minimal value—contents: read—at the root level. This ensures all jobs restrict their GITHUB_TOKEN appropriately without the need to repeat the setting for each job. This change should be made at the top-level of the YAML file, right after the name: key and before the on: key.

---

The best way to fix the problem is by adding an explicit permissions block at the workflow/root level in the .github/workflows/python-tests.yml file, ensuring the GITHUB_TOKEN has only the least privilege required. In this case, the jobs simply check out code, run tests, upload artifacts, and report coverage; none appear to need write permissions. The minimum necessary permission to fetch the source code is contents: read. The block should be inserted after the name: line and before the on: block for clarity and best practice.

Steps:

• Edit the top of .github/workflows/python-tests.yml.
• After line 1 (name: Python Tests), insert:

  permissions:
    contents: read

• No other code changes, dependencies, or method definitions are needed.

---

To fix this issue, add an explicit permissions block to the workflow file. The recommended and most secure approach is to set the minimal permissions needed for all jobs at the workflow root level. For the workflow provided, all the jobs utilize read-only access at most: they read code and upload artifacts to Actions/Codecov, but do not need to write to repo contents, issues, or pull requests.

What to do:

• Add permissions: contents: read at the root level of the workflow, just below the name: statement, so that all jobs inherit this unless overridden.
• This change is made near the top of .github/workflows/python-tests.yml, between the name: and on: lines.
• No imports or new packages are required, only a YAML change.