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

Requirement	Version
Python	>= 3.10
pytest	>= 9.0
pywin32	>= 311
OS	Windows (Named Pipes)
Host	RevitDevTool add-in loaded

Supported hosts

Supported today

host_name	Application	Pipe prefix
revit	Autodesk Revit	Revit
autocad	AutoCAD	AutoCad
civil3d	Civil 3D	Civil3D
plant3d	Plant 3D	Plant3D
acadarch	AutoCAD Architecture	AcadArch
acadmech	AutoCAD Mechanical	AcadMech
acadmep	AutoCAD MEP	AcadMep
acadelec	AutoCAD Electrical	AcadElec
acadmap3d	AutoCAD Map 3D	AcadMap3D

In progress

host_name	Application	Status
navisworks	Navisworks	Not validated
rhino	Rhino	Not validated
tekla	Tekla Structures	Not validated

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

Option	Default	Description
host_name	"revit"	Target host — use Supported today names only.
host_version	—	Version string ("2025", "8.0", …). Required for launch.
force_launch	false	Force a new host instance (skip reuse). Requires host_version.
per_test_timeout	"60"	Per-test budget (seconds). The tests/run pipe wait is this × collected tests.
launch_timeout	"180"	Wait for host pipe after launch (seconds).
host_pipe	—	Explicit pipe name (skip discovery).

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 conftest.py; RevitDevTool installs them before run:

# /// 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

Path	Purpose
src/revitdevtool_pytest/	Plugin source (published wheel)
tests/Revit/	Revit integration tests + schedule/ helpers
tests/Civil3d/	Civil 3D / AutoCAD API tests

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