“use strict”; const iconvLite = require(“iconv-lite”); const supportedNames = require(“./supported-names.json”); const labelsToNames = require(“./labels-to-names.json”);

const supportedNamesSet = new Set(supportedNames);

// encoding.spec.whatwg.org/#concept-encoding-get exports.labelToName = label => {

label = String(label).trim().toLowerCase();

return labelsToNames[label] || null;

};

// encoding.spec.whatwg.org/#decode exports.decode = (buffer, fallbackEncodingName) => {

let encoding = fallbackEncodingName;
if (!exports.isSupported(encoding)) {
  throw new RangeError(`"${encoding}" is not a supported encoding name`);
}

const bomEncoding = exports.getBOMEncoding(buffer);
if (bomEncoding !== null) {
  encoding = bomEncoding;
}

// iconv-lite will strip BOMs for us, so no need to do the stuff the spec does

return iconvLite.decode(buffer, encoding);

};

// github.com/whatwg/html/issues/1910#issuecomment-254017369 exports.getBOMEncoding = buffer => {

if (buffer[0] === 0xFE && buffer[1] === 0xFF) {
  return "UTF-16BE";
} else if (buffer[0] === 0xFF && buffer[1] === 0xFE) {
  return "UTF-16LE";
} else if (buffer[0] === 0xEF && buffer[1] === 0xBB && buffer[2] === 0xBF) {
  return "UTF-8";
}

return null;

};

exports.isSupported = name => {

return supportedNamesSet.has(String(name));

};