Function parseHeaders

fetch.js:433–459

(rawHeaders)

}

function parseHeaders(rawHeaders) {
  var headers = new Headers()
  // Replace instances of \r\n and \n followed by at least one space or horizontal tab with a space
  // https://tools.ietf.org/html/rfc7230#section-3.2
  var preProcessedHeaders = rawHeaders.replace(/\r?\n[\t ]+/g, ' ')
  // Avoiding split via regex to work around a common IE11 bug with the core-js 3.6.0 regex polyfill
  // https://github.com/github/fetch/issues/748
  // https://github.com/zloirock/core-js/issues/751
  preProcessedHeaders
    .split('\r')
    .map(function(header) {
      return header.indexOf('\n') === 0 ? header.substr(1, header.length) : header
    })
    .forEach(function(line) {
      var parts = line.split(':')
      var key = parts.shift().trim()
      if (key) {
        var value = parts.join(':').trim()
        try {
          headers.append(key, value)
        } catch (error) {
          console.warn('Response ' + error.message)
        }
      }
    })
  return headers
}

Body.call(Request.prototype)