Question

Is it possible to comment out this line in the new app/assets/application.js file? If so, how?

//=require jquery_ujs

I mean, it’s already commented out to avoid being misconstrued as CoffeeScript or JavaScript, but it’s obviously serving a purpose still.

Answer 1

Taken from the Sprockets 1.02 github (Sprockets 2 is what rails 3.1 uses to accomplish asset loading):

How Sprockets handles comments

Use single-line (//) comments in
JavaScript source files for comments
that don’t need to appear in the
resulting concatenated output.Use
multiple-line (/* … */) comments for
comments that should appear in the
resulting concatenated output, like
copyright notices or descriptive
headers. PDoc (/** … **/)
documentation comments will not be
included in the resulting
concatenation.

Comments beginning with //= are
treated by Sprockets as directives.
Sprockets currently understands two
directives, require and provide.

What this means is that //= jquery_ujs is a directive. It instructs Sprockets to include the jquery_uls file when it compiles all the jquery files.

If you don’t want that file included, just remove the equals sign and the directive becomes a comment.