pytest

Run CPython pytest tests inside a live Revit or AutoCAD-family host through the RevitDevTool pytest bridge. The client package is revitdevtool_pytest 0.4.0. Collection and reporting happen in the local Python process; Revit API code executes in the host.

Install and configure

From the test project, add the pinned client package and run through uv:

uv add "revitdevtool_pytest==0.4.0"
uv run pytest --host revit --host-version 2025 -v

The test client connects to the selected host automatically. Choose the host and version with the command-line options shown below.

Example configuration:

[tool.pytest.ini_options]
testpaths = ["tests"]
python_files = ["test_*.py"]

Fixtures and host context

Use bridge fixtures for the host, active document, and cleanup. Tests should leave the document in a predictable state and perform writes inside valid transactions.

def test_active_document(revit):
    assert revit.active_document is not None

Useful options include --force-launch, --launch-timeout, --per-test-timeout, and --host-pipe for connecting to a known host.

Debugging

CPython starts debugpy during initialization. Attach VS Code to the port shown by RevitDevTool, usually 5678, before running the test. See Attach Debugger.

Troubleshooting

Symptom	Check
Host API import fails locally	The test must execute through the bridge; host API code cannot run in ordinary external Python
No host found	Start the host with RevitDevTool loaded or use --force-launch and --host-version
Fixture unavailable	Check the installed client package and fixture name in the project configuration
Test suite is locked	End the other pytest process for the same host, version, and workspace

For the full wire and fixture reference, see Testing Overview.