Research: Why NPM pack/publish doesn't include files consistently

[jhnsnc]

Sometimes when I pack/publish the NPM package, files do not get included. Yesterday, I was having issues getting the common/ folder to be included even though it is specified in the "files" array in package.json.

Tonight I was having issues getting README.md to get included even after committing, packing, publishing several new versions.

Why is my machine not reliably packing all the appropriate files for publishing? Perhaps it has something to do with being on my Windows machine and running the commands through Cygwin? I should probably try it on a Mac and/or using the Linux subsystem bash terminal on my Windows machine.