uglify js error unexpected token eof “undefined”

Question

So I installed npm using npm install uglify-js

I run a command which is:

cat file1.js file2.js .. fileN.js | uglifyjs -o files.min.js

Answer 1

I got this same error with ember:

Build Error (UglifyWriter)
Unexpected token: eof (undefined)

The solution was to update ember-cli-moment-shim to version v3.8.0