function linkChecker()

in gulpfile.js [867:939]

• 30 lines of code
• 9 McCabe index (conditional complexity)

function linkChecker(options) {
  var deferred = Q.defer();
  var options = options || {};

  var blcOptions = options.blcOptions || {};
  var customData = options.customData || {};

  // don't bother reporting bad links matching this RegExp
  var excludeBad = argv.excludeBad ? new RegExp(argv.excludeBad) : (options.excludeBad || '');

  var previousPage;
  var siteUrl = argv.url || options.url || 'https://angular.io/';

  // See https://github.com/stevenvachon/broken-link-checker#blcsitecheckeroptions-handlers
  var handlers = {
    robots: function(robots, customData){},
    html: function(tree, robots, response, pageUrl, customData){
      // gutil.log('Scanning ' + pageUrl);
    },
    junk: function(result, customData){},

    // Analyze links
    link: function(result, customData){
      if (!result.broken) { return; }
      if (excludeBad && excludeBad.test(result.url.resolved)) { return; }

      var currentPage = result.base.resolved
      if (previousPage !== currentPage) {
        previousPage = currentPage;
        fs.appendFileSync(outputFile, '\n' + currentPage);
        gutil.log('broken: ' + currentPage);
      }
      var msg = '\n  [' + result.html.location.line + ', ' + result.brokenReason + '] ' + result.url.resolved;
      fs.appendFileSync(outputFile, msg);
      // gutil.log(msg);
      // gutil.log(result);
    },

    page: function(error, pageUrl, customData){},
    site: function(error, siteUrl, customData){},

    end: function(){
      var stopTime = new Date().getTime();
      var elapsed = 'Elapsed link-checking time: ' + ((stopTime - startTime)/1000) + ' seconds';
      gutil.log(elapsed);
      fs.appendFileSync(outputFile, '\n'+elapsed);
      gutil.log('Output in file: ' + outputFile);
      deferred.resolve(true);
    }
  };

  // create an output file with header.
  var outputFile = path.join(process.cwd(), 'link-checker-results.txt');
  var header = 'Link checker results for: ' + siteUrl +
               '\nStarted: ' + (new Date()).toLocaleString() +
               '\nExcluded links (blc file globs): ' + blcOptions.excludedKeywords +
               '\nExcluded links (custom --exclude-bad regex): ' + excludeBad.toString() + '\n\n';
  gutil.log(header);
  fs.writeFileSync(outputFile, header);

  var siteChecker = new blc.SiteChecker(blcOptions, handlers);
  var startTime = new Date().getTime();

  try {
    gutil.log('link checker started');
    siteChecker.enqueue(siteUrl, customData);
  } catch (err) {
    gutil.log('link checker died');
    console.error('link checker died', err);
    deferred.reject(err);
  }
  return deferred.promise;
}