Files
Taketo Takashima 8054ad55c3 Use :unprocessable_content in generated Devise config for Rack 3.1+, avoid Rack warnings (#5797)
In Rack v3.1.0, the symbol for HTTP status code 422 was changed from `:unprocessable_entity` to `:unprocessable_content`.

As a result, when using rack 3.2 with the following configuration in `config/initializers/devise.rb`, a warning is shown on login failure:

```ruby
# config/initializers/devise.rb
Devise.setup do |config|
  ...
  config.responder.error_status = :unprocessable_entity
```

Warning message:

```sh
/path-to-app/vendor/bundle/ruby/3.4.0/gems/devise-4.9.4/lib/devise/failure_app.rb:80: warning: Status code :unprocessable_entity is deprecated and will be removed in a future version of Rack. Please use :unprocessable_content instead.
```

This warning can be resolved by updating the config as follows:
```diff
# config/initializers/devise.rb
Devise.setup do |config|
  ...
+  config.responder.error_status = :unprocessable_content
-  config.responder.error_status = :unprocessable_entity
```

This fixes the root cause of the warning for new apps by adjusting the generated config during `$ rails generate devise:install` depending on the rack version, so new apps using newer Rack versions generate `error_status = :unprocessable_content` instead of `:unprocessable_entity`.

Existing apps are handled by [latest versions of Rails, which will now transparently convert the code under the hood to avoid the Rack warning](https://github.com/rails/rails/pull/53383), and Devise will use that translation layer when available in the failure app to prevent the warning there as well (since that isn't covered by Rails automatic conversion).

Signed-off-by: Carlos Antonio da Silva <carlosantoniodasilva@gmail.com>
2025-12-31 10:45:09 -03:00
..

===============================================================================

Depending on your application's configuration some manual setup may be required:

  1. Ensure you have defined default url options in your environments files. Here
     is an example of default_url_options appropriate for a development environment
     in config/environments/development.rb:

       config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

     In production, :host should be set to the actual host of your application.

     * Required for all applications. *

  2. Ensure you have defined root_url to *something* in your config/routes.rb.
     For example:

       root to: "home#index"
     
     * Not required for API-only Applications *

  3. Ensure you have flash messages in app/views/layouts/application.html.erb.
     For example:

       <p class="notice"><%= notice %></p>
       <p class="alert"><%= alert %></p>

     * Not required for API-only Applications *

  4. You can copy Devise views (for customization) to your app by running:

       rails g devise:views
       
     * Not required *

===============================================================================