RevitDevTool.PyTest

pytest plugin for testing CAD/BIM API code inside live host applications via the RevitDevTool Named Pipe bridge.

Write tests locally with pytest; execution happens inside the host process. Currently supported: Revit and AutoCAD family only. Navisworks, Rhino, Tekla, and other hosts are in progress.

Installation

pip install revitdevtool_pytest
# or
uv add revitdevtool_pytest

Supported hosts

Supported today

In progress

The plugin registry may list additional names for future work. Treat them as experimental until documented here as Supported today.

Pipe names (pytest only)

The plugin connects to the pytest/control pipe:

DevTools_{Host}_{Version}_{PID}

Examples: DevTools_Revit_2025_12345, DevTools_AutoCad_2026_7890

MCP clients use a separate pipe: DevToolsMcp_{Host}_{Version}_{PID}. Do not point pytest at an MCP pipe.

Quick start (consumer project)

uv init my-host-tests && cd my-host-tests
uv add revitdevtool_pytest pytest

pyproject.toml:

[tool.pytest.ini_options]
host_name = "revit"
host_version = "2025"
force_launch = false
per_test_timeout = "60"
launch_timeout = "180"

tests/conftest.py:

import pytest

@pytest.fixture(scope="session")
def revit_uiapp():
    return __revit__

@pytest.fixture(scope="session")
def revit_doc(revit_uiapp):
    return revit_uiapp.ActiveUIDocument.Document

tests/test_smoke.py:

def test_active_view(revit_doc):
    assert revit_doc.ActiveView is not None

uv run pytest -v

Configuration

CLI flags override INI: --host, --host-version, --force-launch, --per-test-timeout, --launch-timeout, --host-pipe.

Connection behavior

1. force_launch = false (default): scan for DevTools_* pipes matching host_name / host_version, reuse a free instance (suite leasing), or reconnect to a leased PID.
2. No matching instance: auto-launch host when host_version is set (unless --host-pipe pins an existing pipe).
3. force_launch = true: always spawn a new process and wait for its pipe.

Print output

Captured print() from in-host tests is shown for passing tests (same as -rP). No extra flags needed.

Writing tests

• Put host API imports inside functions — collection runs on your machine, execution in the host.
• Use fixtures for __revit__, documents, and rollback helpers.
• Declare suite dependencies with PEP 723 in CPython conftest.py (or test_*.py); RevitDevTool installs them before tests/run. IronPython test_*_ipy.py does not use PEP 723 — ipytests/run never installs packages.

# /// script
# dependencies = ["numpy>=2.0", "polars>=1.0"]
# ///

Revit rollback fixture

@pytest.fixture
def revit_auto_rollback(revit_transaction_service):
    revit_transaction_service.StartChanges()
    try:
        yield revit_transaction_service
    finally:
        revit_transaction_service.RevertChanges()

How it works

1. Local pytest collects tests.
2. Plugin connects to DevTools_{Host}_{Version}_{PID}.
3. Node IDs sent via JSON-RPC method tests/run (BridgeMessage length-prefixed frames).
4. Host runs PytestRunner.py embedded in RevitDevTool (PytestExecutionService on main thread).
5. Results and optional progress notifications return to the client.
6. Plugin maps CaseResult → standard pytest reports.

Developing this repository

Clone and run integration tests against a live host:

cd RevitDevTool.PyTest
uv run pytest -v                          # Revit suite (default)
uv run pytest tests/Revit/test_smoke.py -v
uv run pytest --host civil3d --host-version 2026  # after switching testpaths/host in pyproject.toml

Layout

Revit suite settings in pyproject.toml: testpaths = ["tests/Revit"], pythonpath = ["tests/Revit"] for local schedule imports.

Optional env: REVIT_TEST_MODEL_PATH — path to .rvt for revit_doc fixture (default F:\Project1.rvt).

IDE integration

VS Code / Cursor — python.testing.pytestEnabled: true. Plugin detects vscode_pytest / TEST_RUN_PIPE and disables CLI streaming to avoid duplicate tree entries.

PyCharm — enable pytest as test runner.

License

MIT