unittest (IronPython)

Use Python's unittest.TestCase style for IronPython tests. The pytest package discovers the files, while the test body runs with the IronPython engine inside the Autodesk host.

File naming

Name IronPython tests with the routing suffix:

tests/test_walls_ipy.py

The suffix marks the file as an IronPython test. It does not make the test a CPython test and it does not enable pytest fixtures.

Property	IronPython unittest
Runner command	uv run pytest
Test style	unittest.TestCase
pytest fixtures	Not supported
PEP 723 dependencies	Not supported
Debugger attach	Not supported

Example

import unittest

class WallTests(unittest.TestCase):
    def test_active_document(self):
        self.assertIsNotNone(__revit__.ActiveUIDocument.Document)

Run the test through the same bridge used by CPython:

uv run pytest --host revit --host-version 2025 -v

The test client discovers test_*_ipy.py files separately from regular test_*.py files. A mixed test folder is supported, while each test keeps its own Python runtime semantics.

Engine selection

On Revit, RevitDevTool prefers the pyRevit IronPython engine when pyRevit is installed (default IronPython 2.7.12). Without pyRevit it falls back to IronPython 3.4.2. AutoCAD-family hosts use bundled IronPython 3.4.2.

Limitations

• Do not use pytest fixtures or PEP 723 metadata in an IronPython test.
• Do not expect debugpy or .NET debugger attach for IronPython tests.
• Keep host API access inside valid document, transaction, and document-lock context.
• Use pytest or CPython when modern packages or breakpoints are required.

See Testing Overview for the shared pipe and mixed-tree behavior.