The development requirements are handled by npm, you just need to install them. Please don't open issues, as I don't think that is the proper forum for support problems.
In this case, the application is using the XMLHttp Request to request the Customers. To request data, you must first define the information you need.In this case, the code uses the open() function to specify that it wants to use the GET method of obtaining the data, that the data is located in Customers.XML, and that it wants to make a synchronous request. Note: If you're looking for a full DOM parser, you probably want JSDom.Version 0.2 changed the default parsing settings, but version 0.1.14 introduced the default settings for version 0.2, so these settings can be tried before the migration. We try to make the migration as simple and gentle as possible, but some breakage cannot be avoided. In 0.2 we changed some defaults to parse the XML in a more universal and sane way.
So we disabled = 0.2 returns an array even if the array just includes one element.