test.js

var fs = require('fs');
var crypto = require('crypto');

var filename = 'README.md';
var entryRegex = /\*\s([a-zA-Z]+\s)+\[.*\]\(.*\)/g;

// read the file from the filesystem
fs.readFile(filename, function (err, data) {
  if (err) {
    console.error(err);
    process.exit(1);
  } else {
    // isolate the part of the file that we want
    // to analyse
    var fileData = data.toString();

    var startString = '<!--ALPHA-->';
    var endString = '<!--ALPHAEND-->';
    var startIndex = fileData.search(startString) + startString.length;
    var endIndex = fileData.search(endString);

    var reqSubstr = fileData.substr(startIndex, endIndex);

    // make sure that start and end strings are not
    // a part of the extracted string
    reqSubstr = reqSubstr.replace(startString, '').replace(endString, '');

    // split using a newline to get the list of entries
    var lines = reqSubstr.split('\n');

    // remove all the empty string occurences from the list
    while((remIndex = lines.indexOf('')) != -1) {
      lines.splice(remIndex, 1);
    }

    // check if all entries match regex
    var checkFormat = lines.slice();
    var flag = 0;

    for (i in checkFormat) {
      if (!checkFormat[i].match(entryRegex)) {
        console.log('Fix this entry: ');
        console.log('--------------------');
        console.log(checkFormat[i]);
        console.log('--------------------');
        flag = 1;
      }
    }

    if (flag) {
      process.exit(1);
    }

    // make a copy of the list that we will sort
    var copy = lines.slice();
    copy.sort();

    // calculate the SHA256 hash of the string versions
    // of the two lists
    orgHash = crypto.createHash('sha256').update(lines.toString(), 'utf8').digest('hex');
    sortedHash = crypto.createHash('sha256').update(copy.toString(), 'utf8').digest('hex');

    if (orgHash !== sortedHash) {
      process.exit(1);
    } else {
      process.exit();
    }
  }
});