Running tests#

The BlenderBIM Add-on has three layers of tests for each of its three technology layers. These roughly form a test pyramid, moving from many abstract domain logic tests, to low-level concrete unit tests, to a minimal number of UI and smoke tests. These tests use pytest as the test framework and runner.

All development is expected to use test driven development, and so we expect test coverage to be 100% where it is technically possible to test.

When running tests, Makefile targets are provided for convenience so you can type in a simple command without knowing the internals.

Because the BlenderBIM Add-on depends on IfcOpenShell, it is advised to also run tests for IfcOpenShell and its Python bindings, which is not covered in this document.

Core tests#

The core layer tests are pure Python unit tests with no dependencies on Blender or other modules. They are designed to be fast and easy to run as they test purely abstract domain logic.

Although they are vanilla Python tests, they do not use the Python Mock module. Instead, a lightweight Prophecy mocker class is used, which allows tests to be written in a highly concise, expressive manner. For those coming from a BDD background in Ruby’s RSpec, PHP’s PHPSpec, and PHP’s Prophecy, this is very similar.

$ cd src/blenderbim/
$ make test-core

Tool tests#

The tool layer tests actual concrete functions. These have the following dependencies:

  • pytest-blender, accessible to your system’s Python

  • Blender executable, accessible to pytest-blender on your system’s Python (e.g. through the blender command in your path)

  • pytest, accessible to your Blender Python

  • pytest-bdd, accessible to your Blender Python

You can install the dependencies by running the scripts/setup_pytest.py script in Blender.

Then, run the tests. This will launch Blender headlessly and check the behaviour of all concrete functions.

$ cd src/blenderbim/
$ make test-tool # Test everything
$ make test-tool MODULE=foo # Only test a single module

BlenderBIM Add-on tests#

The BIM layer acts as a full integration test. It is not possible to fully test the UI, as we cannot reliably emit interface signals, nor read the interface as a DOM of sorts. The best we can do is to call Blender operators as a smoke test, and also check simple property and scene changes. It has the same dependencies as the tool tests.

$ cd src/blenderbim/
$ make test-bim # Test everything
$ make test-bim MODULE=foo # Only test a single module