lint.py

#!/usr/bin/env python

import argparse
import os
import pipes
import subprocess
import sys

SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__));
os.chdir(subprocess.check_output(['git', 'rev-parse', '--show-toplevel'],
                                 cwd=SCRIPT_DIR).strip())

def capture(cmd, **args):
    return subprocess.Popen(cmd, stdout=subprocess.PIPE, **args).communicate()[0]

def csplit(nstr, char='\x00'):
    if not nstr:
        return []
    return [l for l in nstr.split(char) if l]

parser = argparse.ArgumentParser()
parser.add_argument('-v', '--verbose', action='store_true')
parser.add_argument('-w', '--allow-warnings', action='store_true',
    help="Only fail on eslint errors.")
parser.add_argument('-f', '--fast', action='store_true',
    help='"fast" mode. Run only on changed files.')
parser.add_argument('--git-remote', default='refs/remotes/origin/master',
    help="(fast mode only) branch to look for changed files against")
parser.add_argument('-u', '--ignore-untracked', action='store_true',
    help="(fast mode only) ignore untracked files.");

opts = parser.parse_args()

eslint_args = ['--ext', '.jsx,.js']
if not opts.allow_warnings:
    eslint_args.append('--max-warnings=0')

if opts.fast:
    eslint_args.append('--cache')
    ancestor = capture(['git', 'merge-base', 'HEAD', opts.git_remote]).strip()
    paths = csplit(capture(['git', 'diff', '--diff-filter=AM', '--name-only', '-z',
                            '--no-renames', '--no-color', ancestor,
                            '--', '*.js', '*.jsx']))

    if not opts.ignore_untracked:
        paths.extend(csplit(capture(['git', 'ls-files', '--others', '--exclude-standard',
                                     '-z', '--', '*.js', '*.jsx'])))
else:
    paths = ['.']

if not paths:
    print('No js files to lint -- skipping')
    sys.exit(0)

eslint_args.extend(p for p in paths if p)

# prefer local eslint.
eslint = subprocess.check_output(
    ['which', 'eslint'],
    env={'PATH': './node_modules/.bin:' + os.environ['PATH']}).strip()

if opts.verbose:
    os.environ['DEBUG'] = 'eslint:cli-engine'

print '>', eslint, ' '.join(pipes.quote(c) for c in eslint_args)

os.execv(eslint, [eslint] + eslint_args)