Pytest Fixtures and Options

While the ROAST test framework is test-tool agnostic, pytest fixtures have been provided to simplify test creation and execution. The fixtures provided are grouped into three categories.

Configuration Generation
Board Acquisition
- board_session fixtures
- board fixture
Scenario Generation
- create_scenario fixture

Configuration Generation 

The features in this section provide functionality related to generating a test configuration.

create_configuration fixture 

This fixture will generate a configuration based on the location of the test file being executed. The optional parameters to this fixture are:

test_name - This specifies a test configuration to be retrieved in a subdirectory relative to the test file. If not provided, this will resolve to request.node.name.
base_params - The list provided is written to the base_params attribute of the configuration.
params - This allows a list of test configurations to be retrieved in subdirectories relative to the test file. This is typically used to retrieved definitions when parameterizing tests.
overrides - This allows variable overrides to be specified. This can be another Python file, key/value pair, or both. If not provided, it will attempt to use pytest.override from the --override option.
machine - This specifies an override file based on the machine type where the test will be executed. If not provided, it will attempt to use pytest.machine from the --machine option.

--override option 

This option allows the user to specify an override file, key/value pairs, or both to override variable values in the configuration generated from configuration files.

Examples:

To override a variable named “my_version”:

$ pytest --override my_version=2020.1

To override a list variable named “my_list”:

$ pytest --override my_list=c,d

To override multiple variables defined in a Python file:

$ pytest --override /path/to/file.py

To override using both file and key/value pair:

$ pytest --override /path/to/file.py my_version=2020.1

This option allows the user to specific an override file from a specific location. The functionality is the same as using an override by file except that the file location does not need to be specified.

To override using a machine file:

$ pytest --machine zynq

--randomize option 

This option allows the user to set a global randomize configuration parameter to True or False. If not specified, this is set to False by default.

To enable randomization:

$ pytest --randomize

Board Acquisition 

The fixtures in this section provide wrappers for easy board acquisition.

board_session fixtures 

These fixtures will return an instantiated Board object based on the board_type keyword argument. For example, the host_board_session fixture will instantiate a Board object with board_type="host_target" and return a TargetBoard object.

This is accomplished through loading of the TargetBoard object as an entry point upon installation of the roast-xilinx package. Custom Board classes can be written and registered as a plugin where additional fixtures can be created to call the custom classes.

board fixture 

This fixture wraps board_session fixtures and attempts to retrieve the board_interface key from the configuration to be used as the board_type. A valid board type must be specified otherwise an exception will be generated.

Upon return, the Board object will have attributes such as:

config
target_console - console session with a board

Additionally, the start() method will be called to initialized the board.

Scenario Generation 

The fixture is an all-in-one wrapper for configuration generation and automated loading of test suites and system components of a test system.

create_scenario fixture 

This fixture wraps the create_configuration fixture and calls roast.component.scenario() to return a Scenario object which contains handles to all loaded plugins (instantiated classes).