Unit Test Quickstart

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Simple recipes and tips for writing unit tests in the Gramps source code tree.

First, some general procedural and structural notes

  • unit tests are usually created to verify correct functional behavior of a single module of source code.
  • test code goes in a test subdirectory of the subject module's directory
  • the test module should be named with a suffix _test so that it can be found by automatic regression test tools.
  • the leading part of the test will commonly be named the same as the basename (or a variant) of the module under test, leading, for example, to the following files
src/A/B/module.py
src/A/B/test/module_test.py
  • the test subdirectory can contain data or helper programs as required
  • the test and such supplementary elements that are persistent will be maintained as part of the source control system.
  • the test module can create and delete test data during execution. Commonly this would go in a deeper subdir, named to avoid collision with other test programs.
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Running Unit Tests

A single unit test can be run from the top-level Gramps directory.

GRAMPS_RESOURCES=. python -m unittest <test_module>

for example:

GRAMPS_RESOURCES=. python -m unittest gramps.gen.lib.test.date_test

To run all the unit tests use:

GRAMPS_RESOURCES=. python -m unittest discover -p '*_test.py'

For verbose output use the -v flag:

GRAMPS_RESOURCES=. python -m unittest discover -p '*_test.py' -v

Simple Code Recipe

There are only a few firm requirements to fit into the framework. Here is a simple test module that may be considered something of a template.

import unittest

# import the module under test
import ..MyModule                # use your module name
 
# find the data directory
this_dir = os.path.dirname(__file___)
data_dir = os.path.join(this_dir, 'data')
 
# unittest requires a TestCase class containing test function members 
# optional setUp() and tearDown() functions can perform pre/post test housekeeping
class Test_top(unittest.TestCase):
     def setUp(self):
         ...
     def tearDown(self):
         ...

     def test_action_x_leads_to_y(self):
         ..do stuff..
         self.assertTrue(expression, "message to display on failure")
         #see other assert and fail functions in the unittest module

     ..more defs for more tests, more classes for possible grouping logic..

if __name__ == "__main__":
    unittest.main()

Using Your Unit Test

  • create a module_test.py if and whenever it seems like it might be useful
  • create a test subdir if one is not already there
  • one practice might be as follows
cd ...gramps/src
export PYTHONPATH=`pwd`
cd A/B/test
gvim +ba ../module.py module_test.py
  • repeat
    • do some editing
    • do some testing as follows (optional -v shows extra progress messages)
 python module_test.py -v
  • until happy
  • check-in your module code and test code

This works in gramps40/trunk from the toplevel dir to run the existing exportvcard_test.py:

GRAMPS_RESOURCES=$PWD PYTHONPATH=$PWD:$PWD/gramps python gramps/plugins/export/test/exportvcard_test.py

See also Testing Gramps.

Further Information

Perhaps: Just add questions and suggestions to this wiki page!