pyetta

pyetta is a multi-tool made to simplify device on target testing workflows by providing some helpers which modularise the process of on target testing. It provides both a CLI for simple use cases, and a library of components that can simplify creation of test scripts.

The tool can be installed from pip by running the following command.

$ pip install pyetta

Assistance

Detailed information including usage and development goals can be found in the official documentation.

What does it do?

pyetta tries to bridge the gap between embedded systems development (targeting microcontrollers) and CI/CD practises and the concept of continual testing.

It does this in 2 approaches:

• A shipped CLI tool, which enables systems with commonly used frameworks to avoid having to rewrite testing parsers and converters to get the test results from the embedded board to their CI/CD pipeline.
• A library of common tools used within the CLI tool that can assist and simplify the process of writing integration tests against the system.

See the example below, if this sounds like something you have encountered or are encountering, then pyetta may be able to help!

Sample Use Case

A firmware developer develops an application targeting an STM32 microcontroller. This board performs various actions, including interfacing with an SPI-based NAND flash storage device. The developer either writes this driver themselves or they use an existing implementation provided by an external party. Both of these scenarios needs to be tested.

Using pyetta, the developer may simplify their testing of the interaction between the microcontroller and the flash chip. Depending on the testing approach, the functionality can be testing either on-target (with the microcontroller running the tests) or off-target, with a PC running the test on the microcontroller.

For on-target testing, pyetta CLI tool can assist the process of loading firmware onto the board, executing the tests, collecting the data for these tests, and parsing it into a supported and consumable format for the CI/CD pipeline such as JUnit XML.

For off-target testing, pyetta's library of components can assist with developing fixtures via the off-target unit test library (pytest for example).

Project Structure

The project is structured as follows.

root
|---.github: Github specific CI/CD actions
|---docs: Documentation for this project
|---examples: Examples relating to plugin development.
|---pyetta: Project sources
|---test: Test directory for project. 

Project Environment

The project python dependencies can be obtained by using pip to install them. Ensure the [dev] extras is installed in order to perform common developer actions such as testing or building docs or running tests.

Dependencies

The command below will install all the dependencies and the project itself into the standard python locations for your platform.

$ pip install .[dev]

If only the dependencies are needed, you can subsequently call pip uninstall to remove the top level pyetta package.

$ pip uninstall --yes pyetta

Linting, Tests and Coverage

Tests for this project use tox to orchestrate all testing items and is used for preparing a branch for submission. As such, it is the recommended way to do preliminary testing on the development machine as well.

The command below runs tox on the developer's python version, as well as building the documentation. You can specify the standard tox environments for testing specific python versions.

$ tox -p

Coverage can be generated by first combining all the coverage files, then creating the relevant reports.

$ coverage combine
$ coverage html

If you do not wish to use tox, the individual actions supported from tox. ini can be inspected and run manually. Some common manual steps are shown below for reference.

Linting and Analysis

Linting and static analysis is done using flake8. The command below can be used to run the linter.

$ flake8 --show-source

Documentation

Documentation for this project is located in the docs folder and is built by sphinx.

$ sphinx-build docs dist/docs

Running the command above will generate the documentation for this project and save it to a folder dist/docs.

Packaging

Packing is done using python's build command. The command below will build the package for deployment to a python package repository.

$ python -m build

Debugging

A note on debugging pyetta built-in plugins. The built-in plugins can be auto-loaded if the pyetta package is installed and the entrypoint metadata is available to the system. To circumvent this, builtin commands can be injected in via the --extras flag if they are needed during development.