tests.rst

Adding Tests

We will now add tests for the models and views as well as a few functional tests in a new tests subpackage. Tests ensure that an application works, and that it continues to work when changes are made in the future.

The file tests.py was generated as part of the alchemy scaffold, but it is a common practice to put tests into a tests subpackage, especially as projects grow in size and complexity. Each module in the test subpackage should contain tests for its corresponding module in our application. Each corresponding pair of modules should have the same names, except the test module should have the prefix test_.

Start by deleting tests.py, then create a new directory to contain our new tests as well as a new empty file tests/__init__.py.

Warning

It is very important when refactoring a Python module into a package to be sure to delete the cache files (.pyc files or __pycache__ folders) sitting around! Python will prioritize the cache files before traversing into folders, using the old code, and you will wonder why none of your changes are working!

Test the views

We'll create a new tests/test_views.py file, adding a BaseTest class used as the base for other test classes. Next we'll add tests for each view function we previously added to our application. We'll add four test classes: ViewWikiTests, ViewPageTests, AddPageTests, and EditPageTests. These test the view_wiki, view_page, add_page, and edit_page views.

Functional tests

We'll test the whole application, covering security aspects that are not tested in the unit tests, like logging in, logging out, checking that the basic user cannot edit pages that it didn't create but the editor user can, and so on.

View the results of all our edits to tests subpackage

Open tutorial/tests/test_views.py, and edit it such that it appears as follows:

src/tests/tutorial/tests/test_views.py

Open tutorial/tests/test_functional.py, and edit it such that it appears as follows:

src/tests/tutorial/tests/test_functional.py

Note

We're utilizing the excellent WebTest package to do functional testing of the application. This is defined in the tests_require section of our setup.py. Any other dependencies needed only for testing purposes can be added there and will be installed automatically when running setup.py test.

Running the tests

We can run these tests similarly to how we did in running_tests:

On UNIX:

$ $VENV/bin/py.test -q

On Windows:

c:\pyramidtut\tutorial> %VENV%\Scripts\py.test -q

The expected result should look like the following:

......................
22 passed, 1 pytest-warnings in 5.81 seconds

Note

If you use Python 3 during this tutorial, you will see deprecation warnings in the output, which we will choose to ignore. In making this tutorial run on both Python 2 and 3, the authors prioritized simplicity and focus for the learner over accommodating warnings. In your own app or as extra credit, you may choose to either drop Python 2 support or hack your code to work without warnings on both Python 2 and 3.