replace is not defined, error thrown at var preProcessedHeaders = rawHeaders.replace(/\r?\n[\t ]+/g, ' ');

[datasmithadvtech]

parseHeaders(rawHeaders) is called with following value for rawHeaders

{
"{\n "cache-control"": ""no-cache, no-store, max-age=0, must-revalidate","
}

i believe since this isn't an array, replace is undefined so this statement fails,

Note: xhr.getAllResponseHeaders() is not returning a array of all headers , there are about a dozen

var preProcessedHeaders = rawHeaders.replace(/\r?\n[\t ]+/g, ' ');

called by:
xhr.onload = function() {
var options = {
status: xhr.status,
statusText: xhr.statusText,
headers: parseHeaders(xhr.getAllResponseHeaders() || '')
};

passing

{
"{\n "cache-control"": ""no-cache, no-store, max-age=0, must-revalidate","
}

[datasmithadvtech]