pre-commit

#!/usr/bin/env python2
#-*- mode: python -*-
# ###################################################
# Copyright (C) 2008-2016 The Unknown Horizons Team
# team@unknown-horizons.org
# This file is part of Unknown Horizons.
#
# Unknown Horizons is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# ###################################################

"""
INFORMATION:
This is the pre-commit hook used on the unknown horizons team. It checks the
staged files using pyflakes and checks for added print statements. It gives you
the choice to cancel a commit if errors are found.

= Installation =

== Windows ==
Copy this file to .git/hooks/
Your done! If the hook is updated you have to copy it again manually.

== Linux/MacOS ==
cd .git/hooks
ln -s ../../development/pre-commit pre-commit
This will create a soft-link to the file in development and therefore keep it
updated automatically.

"""

from subprocess import Popen, PIPE
import sys
import re
import Tkinter
import tkMessageBox

syntax_checker = "pyflakes-python2"

class bcolors:
	"""Colors used to color the output"""
	HEADER = '\033[95m'
	OKBLUE = '\033[94m'
	OKGREEN = '\033[92m'
	WARNING = '\033[93m'
	FAIL = '\033[91m'
	ENDC = '\033[0m'

def cleanup(pyflakeserrorlist):
	"""Methode used to filter bad errors from pyflakes"""
	for line in list(pyflakeserrorlist):
		if "undefined name '_'" in line or "undefined name 'N_'" in line:
			# These messages are produced because of gettext and cannot be removed
			# Therefore we ignore the error
			del pyflakeserrorlist[pyflakeserrorlist.index(line)]
	return pyflakeserrorlist

def run(command):
	"""Runs a command and returns a triple with the output: (returnvalue, stdout, stderr)"""
	p = Popen(command.split(), stdout=PIPE, stderr=PIPE)
	p.wait()
	return p.returncode, [ line.strip() for line in p.stdout.readlines()], [line.strip() for line in p.stderr.readlines()]

_, files_modified, _= run("git diff-index --name-only HEAD")

exitcode = 0
# Find words not suitable to be included in commits
invalid_regexes = [
	'print ',
	'pdb',
	'set_trace']

for fname in files_modified:
	if fname.strip().endswith(".py"):
		# Check using pyflakes
		exit_code, stderrors, errors = run("%s %s"%(syntax_checker, fname))
		stderrors = cleanup(stderrors)
		errors = cleanup(errors)
		stderrors.extend(errors)

		if stderrors:
			print >>sys.stderr, "\rChecking syntax on %s:" %(fname), bcolors.FAIL, "FAILED!", bcolors.ENDC
			for line in stderrors:
				print >>sys.stderr, "\t", line
			exitcode = exit_code
		else:
			print >>sys.stderr, "\rChecking syntax on %s:" %(fname), bcolors.OKGREEN, "OK!", bcolors.ENDC

		# Check for added prints or other stuff
		print >>sys.stderr, "Checking for 'print', 'pdb' and 'set_trace' on %s: ... " %(fname),
		_, output, _ = run("git diff-index -u HEAD %s" %(fname))
		found_re = False
		for i, line in enumerate(output):
			if not line.startswith('+'):
				continue

			for r in invalid_regexes:
				if re.search(r, line):
					if not found_re:
						print >>sys.stderr, "\rChecking for '%s' on %s:" % (r, fname), bcolors.FAIL, "FAILED!", bcolors.ENDC
						found_re = True
					if i > 0:
						print "\t", output[i-1]
					print "\t", bcolors.FAIL, line, bcolors.ENDC
					if len(output) > i + 1:
						print "\t", output[i+1]
		if found_re:
			exitcode = 1
		else:
			print >>sys.stderr, "\rChecking for 'print', 'pdb' and 'set_trace' on %s:" %(fname), bcolors.OKGREEN, "OK!", bcolors.ENDC


if exitcode == 1:
	# Hide root Tk window that is always created
	window = Tkinter.Tk()
	window.wm_withdraw()

	if not tkMessageBox.askyesno("Errors have been detected", "Cancel Commit?"):
		exitcode = 0
sys.exit(exitcode)