Rails 5 deprecation warning

[connorshea]

I've been testing GitLab with Rails 5, and ran into this deprecation warning when I went to our Letter Opener route:

Started GET "/rails/letter_opener/1468524894_56e3355/rich" for 127.0.0.1 at 2016-07-27 14:05:57 -0600
Processing by LetterOpenerWeb::LettersController#show as HTML
  Parameters: {"id"=>"1468524894_56e3355", "style"=>"rich"}
DEPRECATION WARNING: `render :text` is deprecated because it does not actually render a `text/plain` response. Switch to `render plain: 'plain text'` to render as `text/plain`, `render html: '<strong>HTML</strong>'` to render as `text/html`, or `render body: 'raw'` to match the deprecated behavior and render with the default Content-Type, which is `text/plain`.

Context of deprecating this:

• rails/rails@4b3f8ac
• Introduce render :plain and render :html, make render :body as an alias to render :text rails/rails#12374

I can provide an example app if you'd like me to.

[harigopal]

Related to above, there are deprecation warnings on boot:

DEPRECATION WARNING: before_filter is deprecated and will be removed in Rails 5.1.
Use before_action instead. (called from <class:LettersController> at
.../letter_opener_web-1.3.0/app/controllers/letter_opener_web/letters_controller.rb:5)

These being the culprit:

https://github.com/fgrehm/letter_opener_web/blob/master/app/controllers/letter_opener_web/letters_controller.rb#L5-L6

[josisusan]

The fix can be found on #54

[pseudomuto]

This is resolved on master