Improve controllers and views

app/controllers/units_controller.rb

@@ -1,10 +1,9 @@
 class UnitsController < ApplicationController
-  before_action only: :new do
-    find_unit if params[:id].present?
-  end
-  before_action :find_unit, only: [:edit, :update, :rebase, :destroy]
+  before_action ->{ @unit = current_user.units.find_by!(id: params[:id]) },
+    only: [:new, :edit, :update, :rebase, :destroy],
+    unless: ->{ action_name == "new" && params[:id].nil? }
 
-  before_action except: :index do
+  before_action except: [:index] do
     raise AccessForbidden unless current_user.at_least(:active)
   end
 
@@ -20,7 +19,7 @@ class UnitsController < ApplicationController
     @unit = current_user.units.new(params.expect(Unit::ATTRIBUTES))
     if @unit.save
       @before = @unit.successive
-      flash.now[:notice] = t('.success', unit: @unit)
+      flash.now.notice = t('.success', unit: @unit)
     else
       render_errors @unit
     end
@@ -31,7 +30,7 @@ class UnitsController < ApplicationController
 
   def update
     if @unit.update(params.except(:base_id).expect(Unit::ATTRIBUTES))
-      flash.now[:notice] = t('.success', unit: @unit)
+      flash.now.notice = t('.success', unit: @unit)
     else
       render_errors @unit
     end
@@ -48,18 +47,14 @@ class UnitsController < ApplicationController
 
     @before = @unit.successive
     if @unit.multiplier_previously_changed?
-      flash.now[:notice] = t(".multiplier_reset", unit: @unit)
+      flash.now.notice = t(".multiplier_reset", unit: @unit)
     end
   end
 
   def destroy
     @unit.destroy!
-    flash.now[:notice] = t('.success', unit: @unit)
+    flash.now.notice = t('.success', unit: @unit)
   end
 
   private
-
-  def find_unit
-    @unit = current_user.units.find_by!(id: params[:id])
-  end
 end