Having had issues with Compass based Sprites on a recent Rails 4 upgrade, I'm just testing getting them working on Rails 5 with a basic no frills setup. Firstly install compass-rails which should install the compass dependency.
Grab the Slik icons from FamFamFam and unpack them into app/assets/images/slik. Add the following to your CSS / Sass file.
@import 'compass' @import "slik/*.png" @include all-slik-sprites .slik display: inline-block width: 16px height: 16px margin: 4px background-color: #fff
After a reload Compass with combine the contents of the slik directory into a single png....
Robs-MBP:robl rl$ ls -la app/assets/images/ total 8664 drwxr-xr-x 27 rl staff 918 16 Dec 00:51 . drwxr-xr-x 8 rl staff 272 16 Dec 00:51 .. drwxr-xr-x@ 1002 rl staff 34068 16 Dec 00:38 slik -rw-r--r-- 1 rl staff 281821 16 Dec 00:51 slik-sa4f5bcade8.png
...and adds Sass styles which allow you to do
...to produce something like this. One image load and 700 icons. Woop.
It appears that without commiting the compiled file that rake assets:precompile falls over in development but production seems to precompile the sprite fine.
Robs-MBP:robl rl$ bundle exec rake assets:precompile ... I, [2016-12-16T21:37:56.612717 #3601] INFO -- : Writing /Users/rl/repos/rails5/robl/public/assets/slik-sa4f5bcade8-74b788e911d17ade32471067d52609bb869d028e4b2ac945cad2b966cb312058.png rake aborted! Errno::ENOENT: No such file or directory @ rb_sysopen - /Users/rl/repos/rails5/robl/app/assets/images/slik-sa4f5bcade8.png /Users/rl/.rvm/gems/ruby-2.3.0@rails5/gems/sprockets-3.5.2/lib/sprockets/asset.rb:99:in `binread' /Users/rl/.rvm/gems/ruby-2.3.0@rails5/gems/sprockets-3.5.2/lib/sprockets/asset.rb:99:in `source' /Users/rl/.rvm/gems/ruby-2.3.0@rails5/gems/sprockets-3.5.2/lib/sprockets/utils/gzip.rb:7:in `initialize' /Users/rl/.rvm/gems/ruby-2.3.0@rails5/gems/sprockets-3.5.2/lib/sprockets/manifest.rb:198:in `new'