BDD library for the pytest runner
pytest-bdd-ng combine descriptive clarity of Gherkin language with power and fullness of pytest infrastructure. It enables unifying unit and functional tests, reduces the burden of continuous integration server configuration and allows the reuse of test setups.
Pytest fixtures written for unit tests can be reused for setup and actions mentioned in feature steps with dependency injection. This allows a true BDD just-enough specification of the requirements without obligatory maintaining any context object containing the side effects of Gherkin imperative declarations.
Note
Project documentation: pytest-bdd-ng
Install pytest-bdd-ng
pip install pytest-bdd-ng
Project layout
pytest-bdd-ng automatically collect *.feature files from pytest tests directory. Important to remember, that feature files are used by other team members as live documentation, so it's not a very good idea to mix documentation and test code.
The more features and scenarios you have, the more important becomes the question about their organization. So recommended way is to organize your feature files in the folders by semantic groups:
features ├──frontend │ └──auth │ └──login.feature └──backend └──auth └──login.feature
And tests for this features could be organized in the next manner:
tests └──conftest.py └──functional │ └──__init__.py │ └──conftest.py │ │ └── "User step library used by descendant tests" │ │ │ │ from steps.auth.given import * │ │ from steps.auth.when import * │ │ from steps.auth.then import * │ │ │ │ from steps.order.given import * │ │ from steps.order.when import * │ │ from steps.order.then import * │ │ │ │ from steps.browser.given import * │ │ from steps.browser.when import * │ │ from steps.browser.then import * │ │ │ └──frontend_auth.feature -> ../../features/frontend/auth.feature │ └──backend_auth.feature -> ../../features/backend/auth.feature ...
Step definitions could be organized in the next way
steps └──auth │ └── given.py │ │ └── """User auth step definitions""" │ │ from pytest import fixture │ │ from pytest_bdd import given, when, then, step │ │ │ │ @fixture │ │ def credentials(): │ │ return 'test_login', 'test_very_secure_pass' │ │ │ │ @given('User login into application') │ │ def user_login(credentials): │ │ ... │ └── when.py │ └── then.py └──order │ └── given.py │ └── when.py │ └── then.py └──browser │ └── ... ...
To make links between feature files at features directory and test directory there are few options (for more information please investigate project tests):
- Symlinks
- .desktop files
- .webloc files
- .url files
Note
Link files also could be used to load features by http://