When dragging and dropping multiple files into the renderer, it appears that the contents of the sources are ordered alphabetically, but the filename heading and mapping are unsorted. I have a minimum example in the form of a gist, simply clone and use a file manager to drag and drop the contents onto a running instance of the visualization, and see that under the file2.js heading the contents of file1.js with mapping of file2.js is shown, and vice versa.
