Rails 5, “nil is not a valid asset source”

Question

I have just upgraded to Rails 5 and I have a weird issue while trying to show an image.

I have the exact code I had for Rails 4:

<%= image_tag article         


        

Answer 1

The problem was that I was trying to show an image that did not exist.

Adding unless article.image.blank? solved it:

<%= image_tag article.image_url(:thumb) unless article.image.blank? %>

EDIT: In Rails 4, this would have just rendered nothing without errors, while in Rails 5 it raises an error. So it was, in fact, an upgrade issue.

Big thanks to @BookOfGreg for pointing this out.