entitydecode.js

// from esprima-fb/esprima.js

var XHTMLEntities = {
  quot: '\u0022',
  amp: '&',
  apos: "\u0027",
  lt: "<",
  gt: ">",
  nbsp: "\u00A0",
  iexcl: "\u00A1",
  cent: "\u00A2",
  pound: "\u00A3",
  curren: "\u00A4",
  yen: "\u00A5",
  brvbar: "\u00A6",
  sect: "\u00A7",
  uml: "\u00A8",
  copy: "\u00A9",
  ordf: "\u00AA",
  laquo: "\u00AB",
  not: "\u00AC",
  shy: "\u00AD",
  reg: "\u00AE",
  macr: "\u00AF",
  deg: "\u00B0",
  plusmn: "\u00B1",
  sup2: "\u00B2",
  sup3: "\u00B3",
  acute: "\u00B4",
  micro: "\u00B5",
  para: "\u00B6",
  middot: "\u00B7",
  cedil: "\u00B8",
  sup1: "\u00B9",
  ordm: "\u00BA",
  raquo: "\u00BB",
  frac14: "\u00BC",
  frac12: "\u00BD",
  frac34: "\u00BE",
  iquest: "\u00BF",
  Agrave: "\u00C0",
  Aacute: "\u00C1",
  Acirc: "\u00C2",
  Atilde: "\u00C3",
  Auml: "\u00C4",
  Aring: "\u00C5",
  AElig: "\u00C6",
  Ccedil: "\u00C7",
  Egrave: "\u00C8",
  Eacute: "\u00C9",
  Ecirc: "\u00CA",
  Euml: "\u00CB",
  Igrave: "\u00CC",
  Iacute: "\u00CD",
  Icirc: "\u00CE",
  Iuml: "\u00CF",
  ETH: "\u00D0",
  Ntilde: "\u00D1",
  Ograve: "\u00D2",
  Oacute: "\u00D3",
  Ocirc: "\u00D4",
  Otilde: "\u00D5",
  Ouml: "\u00D6",
  times: "\u00D7",
  Oslash: "\u00D8",
  Ugrave: "\u00D9",
  Uacute: "\u00DA",
  Ucirc: "\u00DB",
  Uuml: "\u00DC",
  Yacute: "\u00DD",
  THORN: "\u00DE",
  szlig: "\u00DF",
  agrave: "\u00E0",
  aacute: "\u00E1",
  acirc: "\u00E2",
  atilde: "\u00E3",
  auml: "\u00E4",
  aring: "\u00E5",
  aelig: "\u00E6",
  ccedil: "\u00E7",
  egrave: "\u00E8",
  eacute: "\u00E9",
  ecirc: "\u00EA",
  euml: "\u00EB",
  igrave: "\u00EC",
  iacute: "\u00ED",
  icirc: "\u00EE",
  iuml: "\u00EF",
  eth: "\u00F0",
  ntilde: "\u00F1",
  ograve: "\u00F2",
  oacute: "\u00F3",
  ocirc: "\u00F4",
  otilde: "\u00F5",
  ouml: "\u00F6",
  divide: "\u00F7",
  oslash: "\u00F8",
  ugrave: "\u00F9",
  uacute: "\u00FA",
  ucirc: "\u00FB",
  uuml: "\u00FC",
  yacute: "\u00FD",
  thorn: "\u00FE",
  yuml: "\u00FF",
  OElig: "\u0152",
  oelig: "\u0153",
  Scaron: "\u0160",
  scaron: "\u0161",
  Yuml: "\u0178",
  fnof: "\u0192",
  circ: "\u02C6",
  tilde: "\u02DC",
  Alpha: "\u0391",
  Beta: "\u0392",
  Gamma: "\u0393",
  Delta: "\u0394",
  Epsilon: "\u0395",
  Zeta: "\u0396",
  Eta: "\u0397",
  Theta: "\u0398",
  Iota: "\u0399",
  Kappa: "\u039A",
  Lambda: "\u039B",
  Mu: "\u039C",
  Nu: "\u039D",
  Xi: "\u039E",
  Omicron: "\u039F",
  Pi: "\u03A0",
  Rho: "\u03A1",
  Sigma: "\u03A3",
  Tau: "\u03A4",
  Upsilon: "\u03A5",
  Phi: "\u03A6",
  Chi: "\u03A7",
  Psi: "\u03A8",
  Omega: "\u03A9",
  alpha: "\u03B1",
  beta: "\u03B2",
  gamma: "\u03B3",
  delta: "\u03B4",
  epsilon: "\u03B5",
  zeta: "\u03B6",
  eta: "\u03B7",
  theta: "\u03B8",
  iota: "\u03B9",
  kappa: "\u03BA",
  lambda: "\u03BB",
  mu: "\u03BC",
  nu: "\u03BD",
  xi: "\u03BE",
  omicron: "\u03BF",
  pi: "\u03C0",
  rho: "\u03C1",
  sigmaf: "\u03C2",
  sigma: "\u03C3",
  tau: "\u03C4",
  upsilon: "\u03C5",
  phi: "\u03C6",
  chi: "\u03C7",
  psi: "\u03C8",
  omega: "\u03C9",
  thetasym: "\u03D1",
  upsih: "\u03D2",
  piv: "\u03D6",
  ensp: "\u2002",
  emsp: "\u2003",
  thinsp: "\u2009",
  zwnj: "\u200C",
  zwj: "\u200D",
  lrm: "\u200E",
  rlm: "\u200F",
  ndash: "\u2013",
  mdash: "\u2014",
  lsquo: "\u2018",
  rsquo: "\u2019",
  sbquo: "\u201A",
  ldquo: "\u201C",
  rdquo: "\u201D",
  bdquo: "\u201E",
  dagger: "\u2020",
  Dagger: "\u2021",
  bull: "\u2022",
  hellip: "\u2026",
  permil: "\u2030",
  prime: "\u2032",
  Prime: "\u2033",
  lsaquo: "\u2039",
  rsaquo: "\u203A",
  oline: "\u203E",
  frasl: "\u2044",
  euro: "\u20AC",
  image: "\u2111",
  weierp: "\u2118",
  real: "\u211C",
  trade: "\u2122",
  alefsym: "\u2135",
  larr: "\u2190",
  uarr: "\u2191",
  rarr: "\u2192",
  darr: "\u2193",
  harr: "\u2194",
  crarr: "\u21B5",
  lArr: "\u21D0",
  uArr: "\u21D1",
  rArr: "\u21D2",
  dArr: "\u21D3",
  hArr: "\u21D4",
  forall: "\u2200",
  part: "\u2202",
  exist: "\u2203",
  empty: "\u2205",
  nabla: "\u2207",
  isin: "\u2208",
  notin: "\u2209",
  ni: "\u220B",
  prod: "\u220F",
  sum: "\u2211",
  minus: "\u2212",
  lowast: "\u2217",
  radic: "\u221A",
  prop: "\u221D",
  infin: "\u221E",
  ang: "\u2220",
  and: "\u2227",
  or: "\u2228",
  cap: "\u2229",
  cup: "\u222A",
  "int": "\u222B",
  there4: "\u2234",
  sim: "\u223C",
  cong: "\u2245",
  asymp: "\u2248",
  ne: "\u2260",
  equiv: "\u2261",
  le: "\u2264",
  ge: "\u2265",
  sub: "\u2282",
  sup: "\u2283",
  nsub: "\u2284",
  sube: "\u2286",
  supe: "\u2287",
  oplus: "\u2295",
  otimes: "\u2297",
  perp: "\u22A5",
  sdot: "\u22C5",
  lceil: "\u2308",
  rceil: "\u2309",
  lfloor: "\u230A",
  rfloor: "\u230B",
  lang: "\u2329",
  rang: "\u232A",
  loz: "\u25CA",
  spades: "\u2660",
  clubs: "\u2663",
  hearts: "\u2665",
  diams: "\u2666"
};

module.exports = function decode(str) {
  return str
    .replace(/&#(\d+);?/g, function (_, code) {
      return String.fromCharCode(parseInt(code, 10));
    })
    .replace(/&#[xX]([A-Fa-f0-9]+);?/g, function (_, hex) {
      return String.fromCharCode(parseInt(hex, 16));
    })
    .replace(/&([^;\W]+;?)/g, function (m, e) {
      var ee = e.replace(/;$/, '');
      var entity = XHTMLEntities[e]
        || (e.match(/;$/) && XHTMLEntities[ee])
      ;
      
      if (entity) {
        return entity;
      }
      else {
        return m;
      }
    })
}