solution2 - URI comparison

solution2.js

function parseURI(uri) {
  /* parse <uri> into invidual components (loosely, some errors allowed) */
  // see https://regex101.com/r/l96l7F/1 for explanation
  var regex = /(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/\/?)?(?:(?:([^:@\/]*):?([^:@\/]*))?@)?([^:\/?#]*)(?::(\d*))?((?:\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?[^?#\/]*)(?:\?([^#]*))?(?:#(.*))?/,

      groupNames = [
        "fullMatch",
        "scheme",
        "username",
        "password",
        "host",
        "port",
        "path",
        "query",
        "fragment"
      ],

      result = regex.exec(uri),
      uriObj = {};

  for (var i = 0; i < result.length; i++) {
    uriObj[groupNames[i]] = result[i] || '';
  }

  return uriObj;
}

function parsePath(path) {
  /* return an array of invidual components in <path> */
  var resolved = [],
      pieces = path.split('/'),
      token;

  for (var i = 0; i < pieces.length; i++) {
    token = decodeURIComponent(pieces[i]);

    if (token && token !== '.' && token !== "..") {
      resolved.push(token);
    } else {
      if (token === '..') {
        resolved.pop();
      }
      if (i === pieces.length - 1) {
        // last token, push a blank string representing a trailing slash
        resolved.push('');
      }
    }
  }

  return resolved;
}

function parseQuery(query) {
  /* return an array of name, values pair from <query> ordered by name */
  var resolvedMap = {},
      resolvedArr = [],
      pieces = query.split('&'),
      token, name, value;

  for (var i = 0; i < pieces.length; i++) {
    token = pieces[i].split('=');
    name = decodeURIComponent(token[0]);
    value = decodeURIComponent(token[1] || '');

    if (!resolvedMap[name]) {
      resolvedMap[name] = [];
      resolvedArr.push([name, resolvedMap[name]]);
    }

    resolvedMap[name].push(value);
  }

  return resolvedArr.sort();
}

function checkURIs(uri1, uri2) {
  /* return whether <uri1> and <uri2> are equivalent */
  if (uri1 === uri2) {
    return true;
  }

  var uriObj1 = parseURI(uri1),
      uriObj2 = parseURI(uri2),
      protocol1 = uriObj1.scheme.toUpperCase() || "HTTP",
      protocol2 = uriObj2.scheme.toUpperCase() || "HTTP";

  if (protocol1 != "HTTP" || protocol2 != "HTTP") {
    throw new RangeError("Comparison involving non-http URI is not yet supported.");
  }

  return protocol1 === protocol2 &&
         decodeURIComponent(uriObj1.username) === decodeURIComponent(uriObj2.username) &&
         decodeURIComponent(uriObj1.password) === decodeURIComponent(uriObj2.password) &&
         uriObj1.host.toUpperCase() === uriObj2.host.toUpperCase() &&
         (uriObj1.port || "80") === (uriObj2.port || "80") &&
         decodeURIComponent(uriObj1.fragment) === decodeURIComponent(uriObj2.fragment) &&
         JSON.stringify(parsePath(uriObj1.path)) === JSON.stringify(parsePath(uriObj2.path)) &&
         JSON.stringify(parseQuery(uriObj1.query)) === JSON.stringify(parseQuery(uriObj2.query));
}


/* unit tests */

try {
  checkURIs(
    "http://username:passwd123@domain.com/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
    "ftp://username:passwd123@domain.com/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash")
  checkURIs(
    "https://username:passwd123@domain.com/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
    "http://username:passwd123@domain.com/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash")
  console.assert(false, "compare with non-http URI")
} catch (e) {
  if (!(e instanceof RangeError)) {
    console.assert(false, "compare with non-http URI")
  }
}

var testData = [
  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "exactly equal"],

  ["hTtP://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "HtTp://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "scheme name case-insensitive"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "//username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "protocol-relative URI"],

  ["http://john:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://John:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "username", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:Passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "password", false],

  ["http://username:passwd123@zendesk.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@ZendesK.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "host name case-insensitive"],

  ["http://username:passwd123@zendesk.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@google.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "host name", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "default port"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:8000/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "port", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#Hash", "fragment", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1", "fragment", false],

  ["http://username:passwd123@domain.com:80?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/?a=3&b=4&a=1#hash", "path (root)"],

  ["http://username:passwd123@domain.com:80/?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc?a=3&b=4&a=1#hash", "path", false],

  ["http://username:passwd123@domain.com:80/abc?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc/?a=3&b=4&a=1#hash", "path (trailing slash)", false],

  ["http://username:passwd123@domain.com:80/abc/?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc/def.html?a=3&b=4&a=1#hash", "path", false],

  ["http://username:passwd123@domain.com:80/abc/def.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc/def.html/?a=3&b=4&a=1#hash", "path (trailing slash)", false],

  ["http://username:passwd123@domain.com:80/users/../../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/temp/%7Esmith/home.html?a=3&b=4&a=1#hash", " path traversal"],

  ["http://username:passwd123@domain.com:80/abc/def/.?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc/def/?a=3&b=4&a=1#hash", " path traversal (trailing dot)"],

  ["http://username:passwd123@domain.com:80/abc/def/..?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/abc/?a=3&b=4&a=1#hash", " path traversal  (trailing dot dot)"],

  ["http://username:passwd123@domain.com:80//users///..//temp////.//%7Esmith////home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "path (loose matching)"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&c=4&a=1#hash", "query name diff", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=9&a=1#hash", "query value diff", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1&b=5#hash", "query extra value", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?b=4&a=3&a=1#hash", "query name ordering"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=1&b=4&a=3#hash", "query value ordering", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b&a=1#hash", "query missing value"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=null&a=1#hash", "query missing value", false],

  ["http://user%3Aname@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://user:name@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "URI encoding (username) (reserved char)", false],

  ["http://user%7Ename@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://user~name@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "URI encoding (username) (unreserved char)"],

  ["http://username:passwd%7E123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd~123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash", "URI encoding (password)"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith%2Fhome.html?a=3&b=4&a=1#hash", "URI encoding (path) (reserved char)", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith%40/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./~smith@/home.html?a=3&b=4&a=1#hash", "URI encoding (path)"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4%26a=1#hash", "URI encoding (query) (reserved char)", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=foo?bar~#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=foo%3Fbar%7E#hash", "URI encoding (query)"],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#hash",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1%23hash", "URI encoding (fragment) (reserved char)", false],

  ["http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#:hash~",
   "http://username:passwd123@domain.com:80/users/../temp/./%7Esmith/home.html?a=3&b=4&a=1#%3Ahash%7E", "URI encoding (fragment)"],

  ["http://www.zendesk.com/product/pricing/",
   "http://www.zendesk.com/support/", "common URL without many components", false],
], d;

for (var i = 0; i < testData.length; i++) {
  d = testData[i];

  if (d[3] === false) {
    console.assert(!checkURIs(d[0], d[1]), d[2]);
    console.assert(!checkURIs(d[1], d[0]), d[2] + " (args reversed)");
  } else {
    console.assert(checkURIs(d[0], d[1]), d[2]);
    console.assert(checkURIs(d[1], d[0]), d[2] + " (args reversed)");
  }
}