Generative section names don't work with empty factor

[The-Compiler]

If I have a tox.ini like this:

[tox]
skipsdist = true

[testenv:foo]
commands =
    {envpython} -c "print('Hello World')"

[testenv:foo-factor]
commands =
    {envpython} -c "print('Factor given')"
    {envpython} -c "print('Hello World')"

Now I'd like to simplify this to use generative section names. I'd expect to either testenv:foo{,-factor} or testenv:foo-{,factor} to work. It looks like neither does.

This:

[tox]
skipsdist = true

[testenv:foo,{-factor}]
commands =
    factor: {envpython} -c "print('Factor given')"
    {envpython} -c "print('Hello World')"

results in:

$ tox -e foo-factor
ERROR: unknown environment 'foo-factor'

(or an empty run without any commands if foo-factor is added to envlist), while this:

[tox]
skipsdist = true

[testenv:foo-{,factor}]
commands =
    factor: {envpython} -c "print('Factor given')"
    {envpython} -c "print('Hello World')"

results in:

$ tox -e foo       
ERROR: unknown environment 'foo'

(as it defines an environment called foo-, not foo).

Am I missing something, or is the currently no way to do this kind of thing?

[gaborbernat]

Generative factors are not supported within section names AFAIK. This would be a new feature request. What you could do instead is:

[tox]
skipsdist = true

[testenv:foo]
commands =
    {envpython} -c "print('Hello World')"

[testenv:foo-factor]
commands =
    {[testenv:foo]commands}
    {envpython} -c "print('Hello World')"

[The-Compiler]

Generative factors are not supported within section names AFAIK.

Yes they are, the problem is just the empty factor (thus making this a bug IMHO, since empty factors work fine elsewhere). This works fine:

[tox]
skipsdist = true

[testenv:foo-factor{1,2}]
commands =
    factor1: {envpython} -c "print('Factor 1 given')"
    factor2: {envpython} -c "print('Factor 2 given')"
    {envpython} -c "print('Hello World')"

$ tox       
foo-factor1 create: ...
foo-factor1 run-test-pre: ...
foo-factor1 run-test: commands[0] | ...
Factor 1 given
foo-factor1 run-test: commands[1] | ...
Hello World

foo-factor2 create: ...
foo-factor2 run-test-pre: ...
foo-factor2 run-test: commands[0] | ...
Factor 2 given
foo-factor2 run-test: commands[1] | ...
Hello World

(output slightly edited for readability)

[gaborbernat]

A PR is welcomed 👍