importlib-metadata again

[asottile]

I've fixed the .egg problem upstream, so we can try this again!

Originally introduced in #199, reverted in #206 to fix #205.

I validated that the fix works by doing the following:

1. First I created an egg of pluggy by running this: python setup.py bdist_egg

2. Next I created a small project which uses pytest-runner:

   # setup.py
   from setuptools import setup
   
   setup(
       name='wat',
       setup_requires=["pytest-runner"],
       tests_require=["pytest"],
   )

   # tests/foo_test.py
   def test(): pass

3. Then I seeded my egg into the directory which setuptools installs into

   mkdir .eggs
   cp ../dist/*.egg .eggs/

4. then I ran python setup.py pytest -- I made sure it didn't download a new egg for pluggy, here's the output of that

$ python setup.py pytest
running pytest
Searching for pytest
Reading https://pypi.org/simple/pytest/
...

Installed /home/asottile/workspace/pluggy/x/.eggs/py-1.8.0-py3.6.egg
Searching for pluggy!=0.10,<1.0,>=0.9
Best match: pluggy 0.11.1.dev21+g18cab33
Processing pluggy-0.11.1.dev21+g18cab33-py3.6.egg

Using /home/asottile/workspace/pluggy/x/.eggs/pluggy-0.11.1.dev21+g18cab33-py3.6.egg

...

Installed /home/asottile/workspace/pluggy/x/.eggs/importlib_metadata-0.15-py3.6.egg

...

============================= test session starts ==============================
platform linux -- Python 3.6.7, pytest-4.5.0, py-1.8.0, pluggy-0.11.1.dev21+g18cab33
rootdir: /home/asottile/workspace/pluggy, inifile: tox.ini
collected 1 item                                                               

tests/foo_test.py .                                                      [100%]

=========================== 1 passed in 0.04 seconds ===========================

[RonnyPfannschmidt]

as follow-up we should take a look at removing the need to "emulate a pkg_resources Distribution"

[nicoddemus]

LGTM, please introduce the CHANGELOG again. 👍

[nicoddemus]

After this gets merged and released, will can pick up pytest-dev/pytest#5063?

[asottile]

After this gets merged and released, will can pick up pytest-dev/pytest#5063?

yep! I need to rebase that

[nicoddemus]

We need to do that before pytest 5.0 then. 👍

Waiting for @goodboy's approval then. 😁

[goodboy]

@asottile nice job!
Looks really sharp and I'm stoked to see some backport action 👍

I had a couple comments that you can probably ignore unless you tend to agree.
Thanks!

[codecov-io]

Codecov Report

Merging #215 into master will decrease coverage by 0.07%.
The diff coverage is 92.1%.

@@            Coverage Diff             @@
##           master     #215      +/-   ##
==========================================
- Coverage   93.22%   93.14%   -0.08%     
==========================================
  Files          14       14              
  Lines        1683     1678       -5     
  Branches      116      116              
==========================================
- Hits         1569     1563       -6     
- Misses         96       98       +2     
+ Partials       18       17       -1

Impacted Files	Coverage Δ
testing/test_pluginmanager.py	96% <100%> (-0.11%)	⬇️
src/pluggy/manager.py	94.53% <83.33%> (-0.38%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7f8f8eb...94ab205. Read the comment docs.

[nicoddemus]

(If there are any small refactorings left, they can be done in a new PR I believe; as it is this is ready to be merged IMHO)

@asottile do you have the time to prepare a new release? 😁

[asottile]

yep! I'll do that in ~an hour or so :)