A bash command line can look like this:

VARxyz=1234 command arg1 arg2 ...

So when you do this:

dir=/c/Users/afabris/Desktop/testfolder/*

You are really doing this:

dir=/c/Users/afabris/Desktop/testfolder/file1 /c/Users/afabris/Desktop/testfolder/file2 /c/Users/afabris/Desktop/testfolder/file3 ...

So.. "/c/Users/afabris/Desktop/testfolder/file2" is the "command" and "/c/Users/afabris/Desktop/testfolder/file3"... are the args..

Neat, eh!

Do this instead:

dir="/c/Users/afabris/Desktop/testfolder/*"