fix MR comments

app/controllers/public/amendments_controller.rb

@@ -14,26 +14,23 @@ class Public::AmendmentsController < Public::BaseController
       return
     end
 
-    @release.amendment_signer_name = release_params[:amendment_signer_name]
-    @release.amendment_signature_base64 = release_params[:amendment_signature_base64]
+    @release.attributes = amendment_params
 
-    render :new unless @release.save
+    render :new unless @release.save(context: :amendment)
   end
 
   private
 
-  def release_params
-    release_type = @contract_template.release_type
-    param_name = "#{release_type}_release".to_s
-    params.require(param_name).permit(:amendment_signer_name, :amendment_signature_base64)
+  def amendment_params
+    params.require(releasable_param.name).permit(:amendment_signer_name, :amendment_signature_base64)
+  end
+
+  def releasable_param
+    @releasable_param ||= ReleasableParam.new(params.to_unsafe_h)
   end
 
   def set_release
-    release_type = @contract_template.release_type
-    param_name = "#{release_type}_release_id".to_s
-    release_id = params[param_name]
-
-    @release = @contract_template.releases.find(release_id)
+    @release = @contract_template.releases.find(releasable_param.id)
   end
 
   def set_contract_template

app/models/concerns/amendmenable.rb

@@ -5,14 +5,15 @@ module Amendmenable
     include ActiveStorageSupport::SupportForBase64
 
     has_one_base64_attached :amendment_signature
+
+    with_options on: :amendment do
+      validates :amendment_signer_name, presence: true
+      validates :amendment_signature, attached: true
+    end
   end
 
   def amendment_signable?
-    if contract_template.present?
-      contract_template.amendment_clause.present?
-    else
-      false
-    end
+    contract_template.present? && contract_template.amendment_clause.present?
   end
 
   def amendment_signed?