Currently the local xhrHttp is defined at require-time.
Unfortunately, libraries for mocking out XMLHttpRequests that rely on replacing global.XMLHttpRequest with a mock do not play nicely with this - you've already gained a reference to the real XMLHttpRequest by the time they replace the global.XMLHttpRequest reference.
Currently the local xhrHttp is defined at require-time.
Unfortunately, libraries for mocking out XMLHttpRequests that rely on replacing global.XMLHttpRequest with a mock do not play nicely with this - you've already gained a reference to the real XMLHttpRequest by the time they replace the global.XMLHttpRequest reference.
Will be submitting a pull request to fix.