Unit tests

The unit tests written for the SoCo module implements elementary checks of whether the individual methods produce the expected results. Such tests are especially useful during re-factoring and to check that already implemented functionality continues to work past updates to the Sonos® units internal software.

Running the unit tests

To run the unit tests enter the unittest folder in the source code checkout and run the unit test execution script execute_unittests.py (it is required that the SoCo checkout is added to the Python path of your system). To run all the unit tests for the SoCo class execute the following command:

python execute_unittests.py --modules soco --ip

where the IP address should be replaced with the IP address of the Sonos® unit you want to use for the unit tests (NOTE! At present the unit tests for the SoCo module requires your Sonos® unit to be playing local network music library tracks from the queue and have at least two such tracks in the queue). You can get a list of all the units in your network and their IP addresses by running:

python execute_unittests.py --list

To get the help for the unit test execution script which contains a description of all the options run:

python execute_unittests.py --help

Unit test code structure and naming conventions

The unit tests for the SoCo code should be organized according to the following guidelines.

One unit test module per class under test

Unit tests should be organized into modules, one module, i.e. one file, for each class that should be tested. The module should be named similarly to the class except replacing CamelCase with underscores and followed by _unittest.py.

Example: Unit tests for the class FooBar should be stored in foo_bar_unittests.py.

One unit test class per method under test

Inside the unit test modules the unit test should be organized into one unit test case class per method under test. In order for the test execution script to be able to calculate the test coverage, the test classes should be named the same as the methods under test except that the lower case underscores should be converted to CamelCase. If the method is private, i.e. prefixed with 1 or 2 underscores, the test case class name should be prefixed with the word Private.


Name of method under test Name of test case class
get_current_track_info GetCurrentTrackInfo
__parse_error PrivateParseError
_my_hidden_method PrivateMyHiddenMethod

Add an unit test to an existing unit test module

To add a unit test case to an existing unit test module Foo first check with the following command which methods that does not yet have unit tests:

python execute_unittests.py --modules foo --coverage

After having identified a method to write a unit test for, consider what criteria should be tested, e.g. if the method executes and returns the expected output on valid input and if it fails as expected on invalid input. Then implement the unit test by writing a class for it, following the naming convention mentioned in section One unit test class per method under test. You can read more about unit test classes in the reference documentation and there is a good introduction to unit testing in Mark Pilgrim’s “Dive into Python” (though the aspects of test driven development, that it describes, is not a requirement for SoCo development).

Special unit test design consideration for SoCo

SoCo is developed purely by volunteers in their spare time. This leads to some special consideration during unit test design.

First of, volunteers will usually not have extra Sonos® units dedicated for testing. For this reason the unit tests should be developed in such a way that they can be run on units in use and with people around, so e.g it should be avoided settings the volume to max.

Second, being developed in peoples spare time, the development is likely a recreational activity, that might just be accompanied by music from the same unit that should be tested. For this reason, that unit should be left in the same state after test as it was before. That means that the play list, play state, sound settings etc. should be restored after the testing is complete.

Add a new unit test module (for a new class under test)

To add unit tests for the methods in a new class follow the steps below:

  1. Make a new file in the unit test folder named as mentioned in section One unit test module per class under test.
  2. (Optional) Define an init function in the unit test module. Do this only if it is necessary to pass information to the tests at run time. Read more about the init function in the section The init function.
  3. Add test case classes to this module. See Add an unit test to an existing unit test module.

Then it is necessary to make the unit test execution framework aware of your unit test module. Do this by making the following additions to the file execute_unittests.py.:

  1. Import the class under test and the unit test module in the beginning of the file

  2. Add an item to the UNITTEST_MODULES dict located right after the ### MAIN SCRIPT comment. The added item should itself be a dictionary with items like this:

     'soco': {'name': 'SoCo', 'unittest_module': soco_unittest,
              'class': soco.SoCo, 'arguments': {'ip': ARGS.ip}},
     'foo_bar': {'name': 'FooBar', 'unittest_module': foo_bar_unittest,
                'class': soco.FooBar,'arguments': {'ip': ARGS.ip}}

    where both the new imaginary foo_bar entry and the existing soco entry are shown for clarity. The arguments dict is what will be passed on to the init method, see section The init function.

  3. Lastly, add the new module to the help text for the modules command line argument, defined in the __build_option_parser function:

    parser.add_argument('--modules', type=str, default=None, help=''
                        'the modules to run unit test for can be '
                        '\'soco\', \'foo_bar\' or \'all\'')

    The name that should be added to the text is the key for the unit test module entry in the UNITTEST_MODULES dict.

The init function

Normally unit tests should be self-contained and therefore they should have all the data they will need built in. However, that does not apply to SoCo, because the IP’s of the Sonos® units will be required and there is no way to know them in advance. Therefore, the execution script will call the function init in the unit test modules, if it exists, with a set of predefined arguments that can then be used for unit test initialization. Note that the function is to be named init , not __init__ like the class initializers. The init function is called with one argument, which is the dictionary defined under the key arguments in the unit test modules definition. Please regard this as an exception to the general unit test best practices guidelines and use it only if there are no other option.