Extract filename obfuscation into module

app/controllers/api/v1/media_controller.rb

@@ -4,13 +4,13 @@ class Api::V1::MediaController < ApiController
   before_action -> { doorkeeper_authorize! :write }
   before_action :require_user!
 
+  include ObfuscateFilename
+  obfuscate_filename :file
+
   respond_to :json
 
   def create
-    file = params[:file]
-    # Change so Paperclip won't expose the actual filename
-    file.original_filename = "media" + File.extname(file.original_filename)
-    @media = MediaAttachment.create!(account: current_user.account, file: file)
+    @media = MediaAttachment.create!(account: current_user.account, file: params[:file])
   rescue Paperclip::Errors::NotIdentifiedByImageMagickError
     render json: { error: 'File type of uploaded media could not be verified' }, status: 422
   rescue Paperclip::Error

app/controllers/settings/profiles_controller.rb

@@ -6,6 +6,10 @@ class Settings::ProfilesController < ApplicationController
   before_action :authenticate_user!
   before_action :set_account
 
+  include ObfuscateFilename
+  obfuscate_filename [:account, :avatar]
+  obfuscate_filename [:account, :header]
+
   def show
   end
 
@@ -20,18 +24,7 @@ class Settings::ProfilesController < ApplicationController
   private
 
   def account_params
-    p = params.require(:account).permit(:display_name, :note, :avatar, :header, :silenced)
-    if p[:avatar]
-        avatar = p[:avatar]
-        # Change so Paperclip won't expose the actual filename
-        avatar.original_filename = "media" + File.extname(avatar.original_filename)
-    end
-    if p[:header]
-        header = p[:header]
-        # Change so Paperclip won't expose the actual filename
-        header.original_filename = "media" + File.extname(header.original_filename)
-    end
-    p
+    params.require(:account).permit(:display_name, :note, :avatar, :header, :silenced)
   end
 
   def set_account

app/models/concerns/obfuscate_filename.rb

+module ObfuscateFilename
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def obfuscate_filename(*args)
+      before_action { obfuscate_filename(*args) }
+    end
+  end
+
+  def obfuscate_filename(path)
+    file = params.dig(*path)
+    return if file.nil?
+
+    file.original_filename = "media" + File.extname(file.original_filename)
+  end
+end