Support installed packages

[gaborbernat]

Resolves #3.

• removes not tracking __main__; this should be covered via the if __main__ part; and I don't think it's bad practice to put code into the __main__.py.
• adds .venv as python environment folders as per https://discuss.python.org/t/trying-to-come-up-with-a-default-directory-name-for-virtual-environments/3750 seems also a popular choice
• adds .nox to also handle people using nox instead of tox

[gaborbernat]

@asottile I think this is now ready for merge and shipping 👍

[asottile]

didn't get to review the whole thing, but here's a first pass

[gaborbernat]

Without being able to automatically set paths, for which upstream does not have an API 🤦‍♂ I'm no longer interested in pursuing this further. I was hoping to shrink my conf from 25 lines to 3, but this would mean I'd need to settle at 10, plus an external dependency.

[gaborbernat]

I live this open for now. Feel free to review it 🤷‍♂ further; I'll keep in the source thing though.

[gaborbernat]

@asottile upstream released a fix for paths get/set_option, added a few fixes to fail when options cannot be satisfied; now it's ready for final review and release 👍

[asottile]

I couldn't get this working with a simple example, so I tried to fix it -- here's my patch on top of your branch: https://github.com/asottile/covdefaults/pull/new/installed-source-asottile

I was validating this by using astpretty using this patch:

diff --git a/setup.cfg b/setup.cfg
index fa1ab4b..bb47bd5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -20,6 +20,8 @@ classifiers =
     Programming Language :: Python :: Implementation :: PyPy
 
 [options]
+package_dir =
+    =src
 py_modules = astpretty
 python_requires = >=3.6.1
 
@@ -35,6 +37,7 @@ universal = True
 
 [coverage:run]
 plugins = covdefaults
+parallel = true
 
 [mypy]
 check_untyped_defs = true

and

mkdir src && git mv astpretty.py src

and then using the coverage commands:

$ coverage erase && coverage run -m pytest tests && coverage combine && coverage report
============================= test session starts ==============================
platform linux -- Python 3.6.9, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: /home/asottile/workspace/astpretty
collected 27 items                                                             

tests/astpretty_test.py ..........................x                      [100%]

======================== 26 passed, 1 xfailed in 0.11s =========================
Name    Stmts   Miss Branch BrPart  Cover   Missing
---------------------------------------------------
---------------------------------------------------
TOTAL      99      0      0      0   100%

2 files skipped due to complete coverage.

[gaborbernat]

@asottile your proposal seems to me that you just put things back to track the source tree and not the installed package.

[gaborbernat]

Investigating this I don't think it's easy to do this reliably for the general case, so I'll retract my feature request. Realized this would only make sense with source layout and that might be too much specialization.