software-testing_09_PyTest_Melvyn/README.md

Session 9 - Banking Unit Tests (PyTest)

A small local Python project aligned with the Session 9 lecture. It includes conditional banking functions, BVA parametrization, negative tests with pytest.raises, a yield fixture in conftest.py, and a mock of the external notification dependency.

Run locally

From the project folder:

python -m venv .venv

Activate the virtual environment:

• Windows PowerShell: .venv\Scripts\Activate.ps1
• macOS/Linux: source .venv/bin/activate

Install dependencies and run tests:

python -m pip install -r requirements.txt
python -m pytest -v
python -m pytest --cov=banking --cov-branch --cov-report=term-missing --cov-report=html

Open htmlcov/index.html for the detailed coverage report. The included coverage_report.txt contains a verified sample run. No deployment, database, or real notification service is needed.

Lecture checklist

• Three conditional operations: deposit, withdraw, transfer (plus constructor validation)
• At least eight test cases, including parametrized boundary values
• Multiple negative pytest.raises tests
• yield fixture with cleanup in tests/conftest.py
• unittest.mock.patch on banking.send_notification (where it is used)
• Statement and branch coverage with a short analysis

Amounts use integer units to avoid floating-point money rounding in this introductory example. notification_service.py deliberately raises if called directly: unit tests mock this external dependency. The transfer example is in-memory and not intended as a production banking implementation.