Nyaa development helper (tool) (#324)

Add new tool for developing (lint/autopep8/isort/test)

New tool uses flake8 and isort for lint checks.
Deprecate existing tool (still works)
Update readme
Update Travis config

dev.py

@@ -0,0 +1,159 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+This tool is designed to assist developers run common tasks, such as
+checking the code for lint issues, auto fixing some lint issues and running tests.
+It imports modules lazily (as-needed basis), so it runs faster!
+"""
+import sys
+
+LINT_PATHS = [
+    'nyaa/',
+    'utils/',
+]
+TEST_PATHS = ['tests']
+
+
+def print_cmd(cmd, args):
+    """ Prints the command and args as you would run them manually. """
+    print('Running: {0}\n'.format(
+        ' '.join([('\'' + a + '\'' if ' ' in a else a) for a in [cmd] + args])))
+    sys.stdout.flush()  # Make sure stdout is flushed before continuing.
+
+
+def check_config_values():
+    """ Verify that all max_line_length values match. """
+    import configparser
+    config = configparser.ConfigParser()
+    config.read('setup.cfg')
+
+    # Max line length:
+    flake8 = config.get('flake8', 'max_line_length', fallback=None)
+    autopep8 = config.get('pycodestyle', 'max_line_length', fallback=None)
+    isort = config.get('isort', 'line_length', fallback=None)
+
+    values = (v for v in (flake8, autopep8, isort) if v is not None)
+    found = next(values, False)
+    if not found:
+        print('Warning: No max line length setting set in setup.cfg.')
+        return False
+    elif any(v != found for v in values):
+        print('Warning: Max line length settings differ in setup.cfg.')
+        return False
+
+    return True
+
+
+def print_help():
+    print('Nyaa Development Helper')
+    print('=======================\n')
+    print('Usage: {0} command [different arguments]'.format(sys.argv[0]))
+    print('Command can be one of the following:\n')
+    print('  lint | check       : do a lint check (flake8 + flake8-isort)')
+    print('  fix  | autolint    : try and auto-fix lint (autopep8)')
+    print('  isort              : fix import sorting (isort)')
+    print('  test | pytest      : run tests (pytest)')
+    print('  help | -h | --help : show this help and exit')
+    print('')
+    print('You may pass different arguments to the script that is being run.')
+    print('For example: {0} test tests/ --verbose'.format(sys.argv[0]))
+    print('')
+    return 1
+
+
+if __name__ == '__main__':
+    assert sys.version_info >= (3, 6), "Python 3.6 is required"
+
+    check_config_values()
+
+    if len(sys.argv) < 2:
+        sys.exit(print_help())
+
+    cmd = sys.argv[1].lower()
+    if cmd in ('help', '-h', '--help'):
+        sys.exit(print_help())
+
+    args = sys.argv[2:]
+    run_default = not (args or set(('--version', '-h', '--help')).intersection(args))
+
+    # Flake8 - lint and common errors checker
+    # When combined with flake8-isort, also checks for unsorted imports.
+    if cmd in ('lint', 'check'):
+        if run_default:
+            # Putting format in the setup.cfg file breaks `pip install flake8`
+            settings = ['--format', '%(path)s [%(row)s:%(col)s] %(code)s: %(text)s',
+                        '--show-source']
+            args = LINT_PATHS + settings + args
+
+        print_cmd('flake8', args)
+        try:
+            from flake8.main.application import Application as Flake8
+        except ImportError as err:
+            print('Unable to load module: {0!r}'.format(err))
+            result = False
+        else:
+            f8 = Flake8()
+            f8.run(args)
+            result = f8.result_count == 0
+
+            if not result:
+                print("The code requires some changes.")
+            else:
+                print("Looks good!")
+        finally:
+            sys.exit(int(not result))
+
+    # AutoPEP8 - auto code linter for most simple errors.
+    if cmd in ('fix', 'autolint'):
+        if run_default:
+            args = LINT_PATHS + args
+
+        print_cmd('autopep8', args)
+        try:
+            from autopep8 import main as autopep8
+        except ImportError as err:
+            print('Unable to load module: {0!r}'.format(err))
+            result = False
+        else:
+            args = [''] + args  # Workaround
+            result = autopep8(args)
+        finally:
+            sys.exit(result)
+
+    # isort - automate import sorting.
+    if cmd in ('isort', ):
+        if run_default:
+            args = LINT_PATHS + ['-rc'] + args
+
+        print_cmd('isort', args)
+        try:
+            from isort.main import main as isort
+        except ImportError as err:
+            print('Unable to load module: {0!r}'.format(err))
+            result = False
+        else:
+            # Need to patch sys.argv for argparse in isort
+            sys.argv.remove(cmd)
+            sys.argv = [sys.argv[0] + ' ' + cmd] + args
+            result = isort()
+        finally:
+            sys.exit(result)
+
+    # py.test - test runner
+    if cmd in ('test', 'pytest'):
+        if run_default:
+            args = TEST_PATHS + args
+
+        print_cmd('pytest', args)
+        try:
+            from pytest import main as pytest
+        except ImportError as err:
+            print('Unable to load module: {0!r}'.format(err))
+            result = False
+        else:
+            result = pytest(args)
+            result = result == 0
+        finally:
+            sys.exit(int(not result))
+
+    sys.exit(print_help())