Valid JS results in Invalid Character Error

[ctorx]

Simply trying to call uglify against a file with this javascript results in an error:

(function (a, b){}(this, function(){ alert(1); }));

Results in the error:

Unexpected character '�'

This is on Windows running gulp in VSCode

I ran into this trying to uglify a file from Bootstrap.Native (https://github.com/thednp/bootstrap.native). There code is wrapped in a similar construct as above, but I replaced theirs with alert(1) for brevity.