Is is possible to write a unit test in api/cpp/tests/rendering/basic.cpp for this bug and others? These changes affect render_internal.cpp

I guess in this particular case it is not render issue. It is just missing stereocenter, which is worth to test using just stereo information (e.g. number of stereo bonds down)

Unfortunately we can't count the up and down bonds for the unit test; in this case, indigo correctly assigns the stereocenters with the correct bond directions, but when the molecule is passed through MoleculeRenderInternal::_prepareSGroups(), the stereocenter to the super atom is forgotten.
Can you suggest another place for a unit test?

for render tests we use regression test with pixel comparison
e.g. https://github.com/epam/Indigo/blob/master/api/tests/integration/tests/rendering/render_reactions.py#L108
in order to execute regression tests need to build indigo-python target

cmake --build . --config Release --target indigo-python
# copy
python -m pip install ..\dist\epam.indigo-1.29.0.dev1-py3-none-win_amd64.whl
# run tests by mask
python3 ..\api\tests\integration\test.py -p render_reactions

also, there are some requirements should be installed to python

python3 -m pip install Pillow

please also merge latest changes from master branch

thanks for the info, I've added a test to render_reactions.py.

I merged the changes from master yesterday. Git merge upstream/master is telling me I am up to date

Do you know what the problem is? My fork is in sync with indigo/master and my branch is up to date with my fork's master and the indigo/master branches

I just verified, your branch is not up-to-date
please do
git fetch upstream
git merge upstream/master

oh, I see, Indigo team didn't backmerge to master the changes about github actions. Will fix it and let you know

please take the latest changes from master

I don't have access to a linx/mac machine in order to generate the reference files for the regression test. How is this normally done?

The windows tests fail due to a diff in the output - do I need to update a output reference file?

• no need to merge from master anymore. It was just one issue with checkout github action upgrade. There is no need to PR to be up-to-date with master branch (and in general it is not possible)
• for windows it seems that the test is running ok, but the console output is different. please replace the expected output from "out" folder into "api/tests/integration/ref/rendering/render_reactions.py.out"
• you can check if test is passed by running python3 api\tests\integration\test.py -p render_reactions locally
• the image from win folder should be copied into linux and mac. Usually the images are the same, but if there are difference - the test will print out the expected result

thanks for the info - I've made the changes

all tests passed, merged, thanks so much for the fix!