add tools to use strict formating

.pre-commit-config.yaml

@@ -0,0 +1,27 @@
+---
+repos:
+    - repo: https://github.com/pre-commit/pre-commit-hooks.git
+      sha: v2.2.1
+      hooks:
+          - id: trailing-whitespace
+          - id: end-of-file-fixer
+          - id: check-json
+          - id: check-yaml
+          - id: debug-statements
+          - id: check-merge-conflict
+    - repo: https://github.com/asottile/seed-isort-config
+      rev: v1.8.0
+      hooks:
+          - id: seed-isort-config
+    - repo: https://github.com/pre-commit/mirrors-isort
+      rev: 'v4.3.18'
+      hooks:
+          - id: isort
+            files: 'tests/(.*)/*.py preview_generator/(.*)/*.py setup.py build_supported_mimetypes_table_rst.py'
+    - repo: https://github.com/ambv/black
+      rev: stable
+      hooks:
+          - id: black
+            language_version: python3.6
+            args: [-l 100]
+            files: 'preview_generator setup.py build_supported_mimetypes_table_rst.py tests'

README.rst

@@ -872,13 +872,51 @@ of the generic abstract class. For example:
 
     ImagePreviewBuilderIMConvert(ImagePreviewBuilder)
 
-Running Pytest :
+Running Tests :
 ----------------
  Pytest is a motor for unit testing
 
-* `pip install pytest`
+* `pip install -e [testing]`
 * go into the "tests" directory : `cd path/to/you/project/directory/tests`
-* run `py.test`
+* run `pytest`
+
+
+Others checks :
+-------------------
+
+Run mypy checks:
+
+     mypy --ignore-missing-imports --disallow-untyped-defs .
+
+Code formatting using black:
+
+     black -l 100 preview_generator setup.py build_supported_mimetypes_table_rst.py tests
+
+Sorting of import:
+
+     isort tests/**/*.py preview_generator/**/*.py setup.py build_supported_mimetypes_table_rst.py
+
+Flake8 check(unused import, variable and many other checks):
+
+    flake8 preview_generator setup.py build_supported_mimetypes_table_rst.py tests
+
+
+Contribute :
+----------------
+install preview_generator with dev dependencies (contains tests dependencies)
+
+   pip install -e '.[dev]
+
+install pre-commit hooks:
+
+  pre-commit install
+
+Launch test :
+
+  pytest
+
+You now can commit and see if pre-commit is ok with your change.
+
 
 ------------
 License

setup.cfg

@@ -0,0 +1,20 @@
+[isort]
+multi_line_output = 3
+line_length = 100
+force_single_line = true
+force_sort_within_sections = true
+combine_as_imports = true
+include_trailing_comma = true
+force_grid_wrap = 0
+use_parentheses = true
+skip_glob = .eggs*,.venv
+known_standard_library = hashlib, logging, mimetype, typing, os, sys, abc, io, json, datetime, subprocess, tempfile
+known_third_party =PIL,PyPDF2,magic,pdf2image,pyexifinfo,pytest,scribus,wand,xvfbwrapper
+known_first_party = preview_generator
+[flake8]
+max-line-length = 100
+show-source = True
+max-complexity = 10
+ignore = C901,E501,I801,W503
+exclude = .venv,.eggs,tools
+doctest = True

setup.py

@@ -36,6 +36,20 @@
     'pathlib',
     'pdf2image'
 ]
+tests_require = [
+    'pytest',
+]
+
+devtools_require=[
+    'flake8',
+    'isort',
+    'mypy',
+    'pre-commit',
+]
+
+# add black for python 3.6+
+if sys.version_info.major == 3 and sys.version_info.minor >= 6:
+    devtools_require.append('black')
 
 if py_version <= (3, 4):
     install_requires.append("typing")
@@ -66,6 +80,10 @@
     install_requires=install_requires,
     python_requires='>= 3.5',
     include_package_data=True,
+    extras_require={
+        'testing': tests_require,
+        'dev': tests_require + devtools_require,
+    },
     test_suite='py.test',  # TODO : change test_suite
     tests_require=testpkgs,
     package_data={