git pre-commit hook for preventing commits that contain untested lines with python/nose

gistfile1.py

#!/usr/bin/env python
import os
import re
import sys

temp_filename = '/tmp/hook_file'

def _read_test_output():
    total_output = {}
    command = "nosetests --with-coverage"
    os.system('%s &> %s' % (command, temp_filename))
    output_lines = open(temp_filename, 'r')
    for line in output_lines:
        split_line = line.split()
        if not split_line:
            continue
        name = split_line[0]
        lines = []
        for line_range in split_line[4:]:
            line_range = line_range.replace(',', '')
            if '-' in line_range:
                values = map(int, line_range.split('-'))
                values[1] += 1
                split_line_range = list(range(*values))
                lines.extend(split_line_range)
            elif line_range.isdigit():
                lines.append(int(line_range))

        if name and lines:
            total_output[ name.replace('.', '/') + ".py"] = lines
    #sys.stdout.write('nose length: %d' % len(total_output))
    return total_output


def _read_diff():
    total_output = {}

    os.system('git diff --cached > %s' %  temp_filename)

    current_filename = None
    lineno = 0

    for line in open(temp_filename).readlines():
        line = line.strip()
        if line.startswith('+++ b/'):
            current_filename = line[6:]
            total_output[current_filename] = []
        elif line.startswith('@@'):
            lineno = int(re.findall('\+([0-9]+),',line)[0]) - 1
        elif line.startswith('+'):
            total_output[current_filename].append(lineno)
        elif line.startswith('-'):
            lineno -= 1
        lineno += 1
    #sys.stdout.write('diff length: %d' % len(total_output))
    return total_output


def main():
    can_commit = True

    diff_output_dict = _read_diff()
    test_output_dict = _read_test_output()

    for filename, linenos in diff_output_dict.iteritems():
        if filename not in test_output_dict:
            sys.stdout.write('you should really test this file -> %s\n' % filename)
            can_commit = False
            continue

        if set(linenos).intersection(test_output_dict[filename]):
            sys.stdout.write("%s %s\n" %  (filename, sorted(set(linenos).intersection(test_output_dict[filename]))))
            can_commit = False

    if not can_commit:
        sys.exit(1)



if __name__ == '__main__':
    sys.stdout.write('petro! the stuff is working!\n')
    main()
    sys.exit(1)