Maintain use of non-digested assets url with rails 5

Question

In upgrading to rails 5, some legacy asset urls needed to be converted from from an explicit form like /assets/pretty_image.png to image_url('pretty_image.png'). This a straight forward change and allows proper caching. But there are emails out there with the old form url. Is there anyway I can continue to let urls like /assets/pretty_image.png still work in production?

Answer 1

It turns out this is a problem with upgrading from rails 4, which stopped allowing both digested and non-digested assets being used. For some reason, the problem did not appear in production until I upgraded to rails 5.

There is a good discussion of some possible solutions here. I used the solution entitled 'Use the Manifest, Rake'. I needed to change from pre-compiling on Heroku to precompiling in development to get the solution to work. I am interested in a solution that still allows precompiling on Heroku.