Testing and tooling

Unit testing

The PyTest framework is used for testing the EMMOntoPy package. It is a unit testing framework with a plugin system, sporting an extensive plugin library as well as a sound fixture injection system.

To run the tests locally install the package with the dev extra (see the developer's setup guide) and run:

$ pytest
=== test session starts ===
...

To understand what options you have, run pytest --help.

Tools

Several tools are used to maintain the package, keeping it secure, readable, and easing maintenance.

Mypy

Mypy is a static type checker for Python.

Documentation: mypy.readthedocs.io

The signs of this tool will be found in the code especially through the typing.TYPE_CHECKING boolean variable, which will be used in the current way:

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from typing import List

Since TYPE_CHECKING is False at runtime, the if-block will not be run as part of running the script or module or if importing the module. However, when Mypy runs to check the static typing, it forcefully runs these blocks, considering TYPE_CHECKING to be True (see the typing.TYPE_CHECKING section in the Mypy documentation).

This means the imports in the if-block are meant to only be used for static typing, helping developers to understand the intention of the code as well as to check the invoked methods make sense (through Mypy).