blacken-docs (#835)

Hi friends, I made a terrific (terrible? terrifying?) thing.

I needed one manual `,` addition to the `setup.py` example so it could be parsed -- otherwise this is fully automated!

Using the new thing I made today: https://github.com/asottile/blacken-docs

Heavily inspired by pytest-dev/pytest#3525.  See also psf/black#292, psf/black#294.

Author: asottile

.pre-commit-config.yaml

@@ -2,9 +2,15 @@ repos:
 -   repo: https://github.com/ambv/black
     rev: 18.5b1
     hooks:
-    - id: black
-      args: [--line-length=99, --safe]
-      python_version: python3.6
+    -   id: black
+        args: [--line-length=99, --safe]
+        language_version: python3.6
+-   repo: https://github.com/asottile/blacken-docs
+    rev: v0.1.0
+    hooks:
+    -   id: blacken-docs
+        additional_dependencies: [black==18.5b1]
+        language_version: python3.6
 -   repo: https://github.com/asottile/seed-isort-config
     rev: v0.1.0
     hooks:

doc/example/jenkins.rst

@@ -25,8 +25,8 @@ using these steps:
 
         import tox
 
-        os.chdir(os.getenv('WORKSPACE'))
-        tox.cmdline() # environment is selected by ``TOXENV`` env variable
+        os.chdir(os.getenv("WORKSPACE"))
+        tox.cmdline()  # environment is selected by ``TOXENV`` env variable
 
 * check ``Publish JUnit test result report`` and enter
   ``**/junit-*.xml`` as the pattern so that Jenkins collects
@@ -58,11 +58,12 @@ with this:
 .. code-block:: python
 
     import urllib, os
+
     url = "https://bitbucket.org/hpk42/tox/raw/default/toxbootstrap.py"
-    #os.environ['USETOXDEV']="1"  # use tox dev version
-    d = dict(__file__='toxbootstrap.py')
+    # os.environ['USETOXDEV']="1"  # use tox dev version
+    d = dict(__file__="toxbootstrap.py")
     exec urllib.urlopen(url).read() in d
-    d['cmdline'](['--recreate'])
+    d["cmdline"](["--recreate"])
 
 The downloaded `toxbootstrap.py` file downloads all necessary files to
 install ``tox`` in a virtual sub environment.  Notes:
@@ -105,19 +106,21 @@ Here is an example:
     import py
     import subprocess
 
+
     def test_linkcheck(tmpdir):
         doctrees = tmpdir.join("doctrees")
         htmldir = tmpdir.join("html")
         subprocess.check_call(
-            ["sphinx-build", "-W", "-blinkcheck",
-              "-d", str(doctrees), ".", str(htmldir)])
+            ["sphinx-build", "-W", "-blinkcheck", "-d", str(doctrees), ".", str(htmldir)]
+        )
+
 
     def test_build_docs(tmpdir):
         doctrees = tmpdir.join("doctrees")
         htmldir = tmpdir.join("html")
-        subprocess.check_call([
-            "sphinx-build", "-W", "-bhtml",
-              "-d", str(doctrees), ".", str(htmldir)])
+        subprocess.check_call(
+            ["sphinx-build", "-W", "-bhtml", "-d", str(doctrees), ".", str(htmldir)]
+        )
 
 3. run ``tox -e docs`` and then you may integrate this environment
    along with your other environments into Jenkins.

doc/plugins.rst

@@ -110,14 +110,17 @@ contents of ``tox_fireworks.py``:
 
     hookimpl = pluggy.HookimplMarker("tox")
 
+
     @hookimpl
     def tox_addoption(parser):
         """Add command line option to display fireworks on request."""
 
+
     @hookimpl
     def tox_configure(config):
         """Post process config after parsing."""
 
+
     @hookimpl
     def tox_runenvreport(config):
         """Display fireworks if all was fine and requested."""
@@ -132,9 +135,12 @@ contents of ``setup.py``:
 
     from setuptools import setup
 
-    setup(name='tox-fireworks', py_modules=['tox_fireworks'],
-          entry_points={'tox': ['fireworks = tox_fireworks']}
-          classifiers=['Framework:: tox'])
+    setup(
+        name="tox-fireworks",
+        py_modules=["tox_fireworks"],
+        entry_points={"tox": ["fireworks = tox_fireworks"]},
+        classifiers=["Framework:: tox"],
+    )
 
 Using the  **tox-** prefix in ``tox-fireworks`` is an established convention to be able to
 see from the project name that this is a plugin for tox. It also makes it easier to find with