Check IIS rewrite map duplicates

check_rewritemap_duplicates.js

'use strict';
const fs = require('fs');
const readline = require('readline');


const [, , filename] = process.argv;

if (!filename) {
  throw Error('NO FILENAME SPECIFIED');
}

const rl = readline.createInterface({
                                      input: fs.createReadStream(filename, 'utf8')
                                    });

let lineNumber = 0;

const originals = {};

rl.on('line', line => {
  lineNumber++;

  const [, originalUrl] = /key="(.+?)"/.exec(line) || [];

  if (!originalUrl) {
    return;
  }
  if (originalUrl in originals) {
    console.log('Duplicate of ' + originals[originalUrl] + ' at line ' + lineNumber, originalUrl);
  }

  originals[originalUrl] = lineNumber;
});