pre-commit

pre-commit

#!/usr/bin/python
import subprocess
import os
import json
import sys

def get_staged_files():
  return subprocess.check_output("git diff --cached --name-only".split()).strip().split('\n')

class Check(object):
  def __init__(self, filetype=None, check_command=None):
    self.filetype = filetype
    self.check_command = check_command

  def check_file(self, ifilename):
    exit_code = 0
    exit_code |= self.check_trailing_whitespace(ifilename)
    exit_code |= self.check_filesize(ifilename)
    if self.check_command is not None:
      dev_null = open(os.devnull, 'w')
      check_command = self.check_command.format(ifilename).split()
      check_process = subprocess.Popen(check_command, stderr=subprocess.PIPE, stdout=dev_null)
      if check_process.wait() != 0:
        print >> sys.stderr, """ERROR: "{}" is not valid {}""".format(ifilename, self.filetype)
        print >> sys.stderr, check_process.stderr.read().strip()
        print >> sys.stderr
        exit_code |= 1
      if 'python' == self.filetype: # cleanup for python files
        compiled_name = "{}c".format(ifilename)
        os.path.exists(compiled_name) and os.remove(compiled_name)
    return exit_code

  def check_trailing_whitespace(self, ifilename):
    exit_code = 0
    with open(ifilename) as infile:
      for lineno, line in enumerate(infile):
        line = line.rstrip('\n\r')
        if line != line.rstrip():
          print """ERROR: Trailing whitespace in "{}", at line {}.""".format(infile.name, lineno + 1)
          exit_code = 1
    return exit_code

  def check_filesize(self, ifilename):
    if os.stat(ifilename).st_size > 545048:
      print >> sys.stderr, """ERROR: "{}" is larger than 5mb, it's probably not code (at the very least it should be modularized).""".format(ifilename)
      return 1
    return 0

class FileChecker(object):
  checks = {
    'py': Check(filetype='python', check_command="python -m py_compile {}"),
    'php': Check(filetype='php', check_command="php -l {}"),
    'json': Check(filetype='json', check_command="python -m json.tool {}"),
    'bash': Check(filetype='bash', check_command="bash -n {}"),
    'sh': Check(filetype='bash', check_command="bash -n {}")
  }

  def check_file(self, ifilename):
    _, _, extension = ifilename.rpartition('.')
    checker = self.checks.get(extension, Check())
    return checker.check_file(ifilename)

def main():
  staged_files = get_staged_files()
  exit_code = 0
  filechecker = FileChecker()
  for ifile in staged_files:
    if not os.path.isfile(ifile):
      continue
    try:
      exit_code |= filechecker.check_file(ifile)
    except Exception as oops:
      print >> sys.stderr, """WARNING: Check logic failed on "{}".""".format(ifile), oops
  if exit_code:
    print >> sys.stderr, "ERROR: Rejecting this commit, please fix issues and try again."
  sys.exit(exit_code)

if "__main__" == __name__:
  main()