I was trying to test the module using the doctest file of r.category:

grass --exec python -m doctest -v test_rcategory_doctest.txt

However, I am getting test failures. Most of them look like this:

Failed example:
    run_command('r.mapcalc', expression='test = if(col() < 3, col(), 2)')
Expected:
    0
Got nothing

How should I fix this? Also, for this new color option, should I write a doctest or a separate unit test(gunittest)?

I was trying to test the module using the doctest file of r.category:

grass --exec python -m doctest -v test_rcategory_doctest.txt

However, I am getting test failures. Most of them look like this:

Failed example:
run_command('r.mapcalc', expression='test = if(col() < 3, col(), 2)')
Expected:
0
Got nothing

This is probably an old doctest, run_command no longer returns returncode by default, but throws exception (the behavior can be changed )

How should I fix this? Also, for this new color option, should I write a doctest or a separate unit test(gunittest)?

I think a pytest like for r.colors.out maybe best.