code: function doSearchInOneFile(filepath, text, queryExpr, maxResultsToReturn) {
      var matches = getSearchMatches(text, queryExpr);
      setResults(filepath, {matches: matches}, maxResultsToReturn);
  }
docs: Finds search results in the given file and adds them to 'results'
  @param {string} filepath
  @param {string} text   contents of the file
  @param {Object} queryExpr
  @param {number} maxResultsToReturn the maximum of results that should be returned in the current search.