ESLint lint pre_commit hook

pre-commit

#!/usr/bin/env node

var exec = require('child_process').exec;
var fs = require('fs');
var eslint = require('../node_modules/eslint/lib/cli');

var files;

var child = exec("git diff-index --cached --name-only HEAD", function(error, stdout, stderr){
  files = stdout.split('\n').filter(function(i){
    return /\.js$/.test(i) && fs.existsSync(i);
  });
  if(files.length === 0){
    return;
  }

  var exitCode = eslint.execute.apply(this, files);
  process.exit(exitCode);
});