MoPyRegtest: A Python enabled simple regression testing framework for Modelica models

Project status

A lightweight, CI-friendly regression testing framework for Modelica models, wrapped in Python's unittest module. Uses OpenModelica for model translation and simulation.

Key features:

• Regression testing — compare simulation results against reference CSV files using configurable metrics and tolerances
• Success-only testing — verify that models compile, build, and simulate successfully (useful for unit test models with built-in assertions)
• Automatic test generation — generate unittest test files for entire Modelica libraries via CLI or Python script
• CSV comparison — compare two CSV result files directly from the command line

Prerequisites

• Python 3 with numpy and pandas
• OpenModelica (>= 1.13.0) with omc on PATH

Installation

# From PyPI
python3 -m pip install --user mopyregtest

# From source
git clone https://github.com/pstelzig/MoPyRegtest.git
cd MoPyRegtest
python3 -m pip install --user .

Verify the CLI: mopyregtest --help

Tip: If mopyregtest is not found, check that pip's script directory is on your PATH.
Run python3 -m pip uninstall mopyregtest (without confirming) to see where pip installed the executable.

Quick start

Regression test (manual)

import mopyregtest

tester = mopyregtest.RegressionTest(
    package_folder="~/.openmodelica/libraries/Modelica 4.0.0+maint.om",
    model_in_package="Modelica.Electrical.Analog.Examples.HeatingRectifier",
    result_folder="./results",
    modelica_version="4.0.0")

tester.compare_result(reference_result="references/HeatingRectifier_res.csv", tol=1e-3)

Success-only test (manual)

tester = mopyregtest.RegressionTest(
    package_folder="~/.openmodelica/libraries/Modelica 4.0.0+maint.om",
    model_in_package="Modelica.Blocks.Examples.Filter",
    result_folder="./results")

tester.check_success()

Auto-generate tests (CLI)

# Regression tests
mopyregtest generate ./gen_tests MyTest ~/".openmodelica/libraries/Modelica 4.0.0+maint.om/" \
    Modelica.Blocks.Sources.Sine,Modelica.Blocks.Sources.Step

# Success-only tests
mopyregtest generate --mode=success ./gen_tests MySimTest ~/".openmodelica/libraries/Modelica 4.0.0+maint.om/" \
    Modelica.Blocks.Examples.Filter

Compare CSV files (CLI)

mopyregtest compare --metric=Lp_dist --tol=0.015 --validated-cols=y reference.csv actual.csv

Documentation

For detailed usage, metrics reference, and worked examples see the documentation.
Runnable examples are in the examples/ folder.

License

MIT — see LICENSE.

Contributing

Contributions are welcome! Please open an issue or pull request.

Authors

• Dr. Philipp Emanuel Stelzig