| commit | author | age | ||
| b731b5 | 1 | .. _qtut_functional_testing: |
| PE | 2 | |
| b1b922 | 3 | =================================== |
| PE | 4 | 06: Functional Testing with WebTest |
| 5 | =================================== | |
| 6 | ||
| 7 | Write end-to-end full-stack testing using ``webtest``. | |
| 8 | ||
| ccf397 | 9 | |
| b1b922 | 10 | Background |
| PE | 11 | ========== |
| 12 | ||
| ccf397 | 13 | Unit tests are a common and popular approach to test-driven development (TDD). |
| SP | 14 | In web applications, though, the templating and entire apparatus of a web site |
| 15 | are important parts of the delivered quality. We'd like a way to test these. | |
| b1b922 | 16 | |
| 19d341 | 17 | `WebTest <https://docs.pylonsproject.org/projects/webtest/en/latest/>`_ is a |
| ccf397 | 18 | Python package that does functional testing. With WebTest you can write tests |
| SP | 19 | which simulate a full HTTP request against a WSGI application, then test the |
| 20 | information in the response. For speed purposes, WebTest skips the | |
| 21 | setup/teardown of an actual HTTP server, providing tests that run fast enough | |
| 22 | to be part of TDD. | |
| 23 | ||
| b1b922 | 24 | |
| PE | 25 | Objectives |
| 26 | ========== | |
| 27 | ||
| ccf397 | 28 | - Write a test which checks the contents of the returned HTML. |
| SP | 29 | |
| b1b922 | 30 | |
| PE | 31 | Steps |
| 32 | ===== | |
| 33 | ||
| 8998f6 | 34 | #. First we copy the results of the previous step. |
| b1b922 | 35 | |
| 8998f6 | 36 | .. code-block:: bash |
| b1b922 | 37 | |
| 8998f6 | 38 | cd ..; cp -r unit_testing functional_testing; cd functional_testing |
| b1b922 | 39 | |
| 8998f6 | 40 | #. Add ``webtest`` to our project's dependencies in ``setup.py`` as a :term:`Setuptools` "extra": |
| b1b922 | 41 | |
| 8998f6 | 42 | .. literalinclude:: functional_testing/setup.py |
| SP | 43 | :language: python |
| 44 | :linenos: | |
| 753580 | 45 | :emphasize-lines: 16 |
| b1b922 | 46 | |
| 8998f6 | 47 | #. Install our project and its newly added dependency. |
| 23fbca | 48 | Note that we use the extra specifier ``[dev]`` to install testing requirements and surround it with double quote marks. |
| 8998f6 | 49 | |
| SP | 50 | .. code-block:: bash |
| 51 | ||
| 23fbca | 52 | $VENV/bin/pip install -e ".[dev]" |
| 8998f6 | 53 | |
| SP | 54 | #. Let's extend ``functional_testing/tutorial/tests.py`` to include a functional test: |
| 55 | ||
| 56 | .. literalinclude:: functional_testing/tutorial/tests.py | |
| 57 | :linenos: | |
| 58 | ||
| 59 | Be sure this file is not executable, or ``pytest`` may not include your tests. | |
| c92f49 | 60 | |
| 8998f6 | 61 | #. Now run the tests: |
| b1b922 | 62 | |
| 8998f6 | 63 | .. code-block:: bash |
| b1b922 | 64 | |
| 8998f6 | 65 | $VENV/bin/pytest tutorial/tests.py -q |
| SP | 66 | .. |
| 67 | 2 passed in 0.25 seconds | |
| b1b922 | 68 | |
| PE | 69 | |
| 70 | Analysis | |
| 71 | ======== | |
| 72 | ||
| ccf397 | 73 | We now have the end-to-end testing we were looking for. WebTest lets us simply |
| SP | 74 | extend our existing ``pytest``-based test approach with functional tests that |
| 75 | are reported in the same output. These new tests not only cover our templating, | |
| 76 | but they didn't dramatically increase the execution time of our tests. | |
| b1b922 | 77 | |
| ccf397 | 78 | |
| SP | 79 | Extra credit |
| b1b922 | 80 | ============ |
| PE | 81 | |
| c92f49 | 82 | #. Why do our functional tests use ``b''``? |
