Add a flake8 check to the testsuite

Author: elprans

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+ignore = E402,E731
+exclude = .git,__pycache__,build,dist,.eggs

requirements-dev.txt

@@ -1,4 +1,4 @@
-pytest>=3.0.7
 Cython>=0.25.2
+flake8>=3.4.1
+pytest>=3.0.7
 uvloop>=0.8.0
-

tests/test__sourcecode.py

@@ -0,0 +1,41 @@
+# Copyright (C) 2016-present the asyncpg authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of asyncpg and is released under
+# the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
+
+import os
+import subprocess
+import sys
+import unittest
+
+
+def find_root():
+    return os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+class TestFlake8(unittest.TestCase):
+
+    def test_flake8(self):
+        root_path = find_root()
+        config_path = os.path.join(root_path, '.flake8')
+        if not os.path.exists(config_path):
+            raise RuntimeError('could not locate .flake8 file')
+
+        try:
+            import flake8  # NoQA
+        except ImportError:
+            raise unittest.SkipTest('flake8 module is missing')
+
+        for subdir in ['asyncpg', 'tests']:
+            try:
+                subprocess.run(
+                    [sys.executable, '-m', 'flake8', '--config', config_path],
+                    check=True,
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.PIPE,
+                    cwd=os.path.join(root_path, subdir))
+            except subprocess.CalledProcessError as ex:
+                output = ex.output.decode()
+                raise AssertionError(
+                    'flake8 validation failed:\n{}'.format(output)) from None

tests/test_codecs.py

@@ -11,7 +11,6 @@
 import math
 import random
 import struct
-import unittest
 import uuid
 
 import asyncpg

tests/test_execute.py

@@ -7,8 +7,6 @@
 
 import asyncio
 import asyncpg
-import inspect
-import warnings
 
 from asyncpg import _testbase as tb