Trac Unit Tests

Many of the Trac Python modules are accompanied by unit tests. You should run the tests whenever making changes, to be confident you haven't broken anything. Note though that the coverage of application code by the unit tests is still rather poor, and even if it were better, not having broken the unit tests does not mean you haven't broken the application! Unit tests do not replace manual testing.

Ideally, you'd also include new unit tests for a change or enhancement, even if you're just submitting a patch. Patches that break the unit tests are a lot less likely to get integrated than patches that add unit tests for the new or changed functionality.

Running the tests

You can run the unit tests from the command line by executing:

python -m trac.test --skip-functional-tests

or unix way:

$ PYTHONPATH=. python trac/test.py --skip-functional-tests

or:

$ make unit-test

See TESTING-README for more details about functional tests.

Assuming the current working directory is where you checked out the Trac code from the SubversionRepository.

This will run all the unit tests, but you can also run only those tests for a specific package or module. For example, to run the unit tests for the trac.versioncontrol package, execute:

python -m trac.versioncontrol.tests.__init__

or if you prefer bash:

 $ PYTHONPATH=. trac/versioncontrol/tests/__init__.py

To run the unit tests for the trac.versioncontrol.cache module, execute:

python -m trac.versioncontrol.tests.cache

or

 $ PYTHONPATH=. trac/versioncontrol/tests/cache.py

If you've made larger changes, then before running the tests, please make sure you've cleaned all .pyc files that may be left after removed or renamed source *.py files:

 $ find . -name *.pyc | xargs rm

Test Database

If you're developing on database different from SQLite, you may want to specify its URI using TRAC_TEST_DB_URI environment variable.

Buildbots

The Trac unit tests are also being run by the ​Python Community Buildbots project. Trac tests are executed regularly on both the latest Python version and development snapshots, so that the scope of backwards incompatible changes to Python can be easily detected. Look for the x86 Gentoo trunk buildslave on both ​Python trunk and ​Python 2.5 (which Trac revision is being tested can be seen from the pre-requisites installation phase, which shows an svn up log).

Adding tests

If you're adding a new module, or you want to add tests for a module that doesn't have any unit tests yet, you'll need to create a new Python module for the unit tests.

For example, say you want to add tests for the module trac.foo (which maps to trac/foo.py). You'll need to create a new module at trac/tests/foo.py and put the tests there. Also, you'll have to edit the __init__.py in the tests package so that your new unit tests get executed with the others.

Utility code for unit tests

The module trac.test​ contains a couple of functions and classes that can help writing unit tests. In particular, it provides an InMemoryDatabase class that can be used to test functionality that requires database access, without having to create an actual database on disk. Also there's a very simple factory for ​mock objects, which you can use to create quick substitutes of the "real" objects for testing.

Optional Dependencies

Some unit-tests depend on:

• ​pytz
• ​Pygments

In addition, the figleaf package can be used to provide code coverage information:

• ​figleaf

These can be installed with easy_install:

easy_install pytz
easy_install Pygments
easy_install figleaf

If these dependencies are not present, certain tests will be skipped.

Troubleshooting

For general advice about Trac debugging, see TracTroubleshooting.

ImportError: no module named tests

If you try to run the tests and you receive

ImportError: No module named tests 

It may mean that you have a version of Trac installed in /usr/lib/pythonX.X/site-packages or /usr/local/lib/pythonX.X/site-packages but you are testing a different version installed elsewhere on your machine.

If so, uninstalling the system version of Trac in /usr/lib/pythonX.X should allow you to run the unit tests, testing your private version.

Installing your virtual environment with --no-site-packages should eliminate this problem.

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See also: TracDev/FunctionalTests, Tickets containing keyword testing