How to prevent UglifyJS from minifying part of a string?

Question

css

I use Prepros. It has an UglifyJS minify function.
In the js code that is minified, there is an IE definition line /*@cc_on + @_jscript_version @*/.
Question: How can I configure UglifyJS so that it doesn't remove this line?
I assume that UglifyJS considers this line as a comment and removes it.

Answer 1

It's better to use UglifyJS2 . He himself understands that you cannot delete "@license" or "@cc_on".

Answer 2

there is an IE definition string

Wah... 2015...
Graceful Degradation also applies to scripts.
Use functions from https://modernizr.com/ to crutch old browsers.

Answer 3

https://github.com/mishoo/UglifyJS2#keeping-copyri...