dynamic_regex.js

function buildRegexp(str) {
  // start the regex with the 
  // ^ start key
  let src = '^' + str;
  
  // replace spaces with regex 
  // that accepts one or more spaces
  // which will handle formatting 
  // inconsistencies
  src = src.replace(/\s+/g, '\\s+');

  // reserved regex characters 
  // (finite list, not complete
  // for this example)
  src = src.replace('.', '\\.');

  // end with the regex $ end key
  src += '$';

  return new RegExp(src);
}

function compare(src, str) {
  let regex = buildRegexp(src);
  
  // trim beginning and ending whitespace
  str = str.trim();

  // log out so I can demo this
  console.log(regex, str);
  
  return regex.test(str);
}

compare('Hello, my name is Evan.', '   Hello,   my name   is  Evan.  ');