feature: split and install dependencies if a comma-space is in the deps line.

[robblovell]

Description

Implementation of feature request: #2506

There are two failed tests, one failure I believe is due to this change, the other I believe to be pre-existing.

I have modified the venv.py file's get_resolved_dependencies() function to split the dependency listed if a comma-space exists in the string. I found that comma's only or spaces only failed around 7 tests and given my unfamiliarity with the codebase, I opted for a more stringent syntax.

I believe that a split on a 'comma only' would be more expected. If someone more familiar with the code might understand why a split on a comma only is problematic and could fix the additional tests, then it should probably be implemented with a split on a comma only.

Giving a list on separate lines is also not supported, but additional work could make that possible.

I have added import copy and used copy.copy to clone the dependency and I am unsure if this is problematic for python 2.7.

I am unsure of backward compatibility issues this might introduce given my unfamiliarity with Tox in general and the code base. Please feel free to critique what I have proposed, alternate solutions would be welcome.

Todo's

TODO: Fix 2 failing tests.
TODO: Multi-line dependency spec
TODO: comma only dependency spec.

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(also see CONTRIBUTING.rst for details)

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• added/updated test(s)
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[gaborbernat]

I don't thinkl this is backwards compatible.

[jugmac00]

I don't thinkl this is backwards compatible.

I am a bit confused why you did not close this pr - is there anything the op could to make this backwards compatible or what do you expect to happen now?

If there is nothing to do, let's close this pr.