Add formatting with black

Author: sliverc

.travis.yml

@@ -19,6 +19,8 @@ matrix:
     - env: TOXENV=py39-django31-drfmaster
 
   include:
+    - python: 3.6
+      env: TOXENV=black
     - python: 3.6
       env: TOXENV=lint
     - python: 3.6

requirements/requirements-codestyle.txt

@@ -1,3 +1,4 @@
+black==20.8b1
 flake8==3.8.4
 flake8-isort==4.0.0
 isort==5.6.4

setup.cfg

@@ -5,29 +5,34 @@ test = pytest
 universal = 1
 
 [flake8]
-ignore = F405,W504
-max-line-length = 100
+max-line-length = 88
+extend-ignore =
+    # whitespace before ':' - disabled as not PEP8 compliant
+    E203,
+    # line too long (managed by black)
+    E501,
+    # usage of star imports
+    # TODO mark star imports directly in code to ignore this error
+    F405
 exclude =
-    snapshots
     build/lib,
-    docs/conf.py,
-    migrations,
     .eggs
     .tox,
     env
     .venv
 
 [isort]
-indent = 4
+multi_line_output = 3
+include_trailing_comma = True
+force_grid_wrap = 0
+use_parentheses = True
+ensure_newline_before_comments = True
+line_length = 88
 known_first_party = rest_framework_json_api
 # This is to "trick" isort into putting example below DJA imports.
 known_localfolder = example
-line_length = 100
-multi_line_output = 3
 skip=
     build/lib,
-    docs/conf.py,
-    migrations,
     .eggs
     .tox,
     env

tox.ini

@@ -20,6 +20,12 @@ setenv =
 commands =
     pytest --cov --no-cov-on-fail --cov-report xml {posargs}
 
+[testenv:black]
+basepython = python3.6
+deps =
+    -rrequirements/requirements-codestyle.txt
+commands = black --check .
+
 [testenv:lint]
 basepython = python3.6
 deps =