ProgramVer — Testing

pip install -r requirements.txt
pytest

14 tests, passing, in about a tenth of a second.

What is covered

tests/test_main.py exercises all four functions:

Test group	Asserts
get_resource_path	The returned path ends with the requested filename
openLicense	A window is created and a file is opened
openEULA	The same, for the EULA
ProgramVer	The widgets are constructed and packed

unittest.mock supplies mock_open for file reads and patches main.Tk, main.Text, main.Label, main.Button, and main.PhotoImage.

What is not covered, and it matters here

Mocking every file read and every widget is what lets the suite run headless in CI. It also means the suite passes on a program that cannot start.

Concretely: test_get_resource_path asserts the returned string ends with dfdlogo.gif. It never checks that the file exists — and it does not. test_openLicense_creates_window patches builtins.open with mock_open, so LICENSE.txt being absent is invisible.

So "100% coverage of the main module", as earlier documentation put it, is true and says nothing about whether the program works. Every line executes; every line executes against a mock.

Worth adding

A test that the files the code opens are actually in the repository:

def test_required_resources_exist(self):
    for name in ("imgs/dfdlogo.gif", "imgs/pythonpoweredlengthgif.gif",
                 "LICENSE.txt", "EULA.txt"):
        self.assertTrue(os.path.exists(get_resource_path(name)), name)

Four lines, no mocking, and it would have caught all three of this repository's High-severity issues. Recorded in internal/known-issues.md.

The general point is worth keeping in mind when extending the suite: mock the display, not the filesystem. The display cannot be exercised in CI; the filesystem can.

CI

.github/workflows/tests.yml runs the suite on push and pull request. pylint.yml lints, codeql-analysis.yml scans, push-to-pypi.yml publishes on release.