change nil checks to check if proc/lambda

Author: myang0

app/controllers/scim_rails/scim_resource_controller.rb

@@ -1,17 +1,17 @@
 module ScimRails
   class ScimResourceController < ScimRails::ApplicationController
     def resource_user
-      ScimRails.config.before_scim_response.call(request.params) unless ScimRails.config.before_scim_response.nil?
+      ScimRails.config.before_scim_response.call(request.params) if ScimRails.config.before_scim_response.respond_to?(:call)
 
-      ScimRails.config.after_scim_response.call(ScimRails.config.resource_user_schema, "RETRIEVED") unless ScimRails.config.after_scim_response.nil?
+      ScimRails.config.after_scim_response.call(ScimRails.config.resource_user_schema, "RETRIEVED") if ScimRails.config.after_scim_response.respond_to?(:call)
 
       json_scim_response(object: nil)
     end
 
     def resource_group
-      ScimRails.config.before_scim_response.call(request.params) unless ScimRails.config.before_scim_response.nil?
+      ScimRails.config.before_scim_response.call(request.params) if ScimRails.config.before_scim_response.respond_to?(:call)
 
-      ScimRails.config.after_scim_response.call(ScimRails.config.resource_group_schema, "RETRIEVED") unless ScimRails.config.after_scim_response.nil?
+      ScimRails.config.after_scim_response.call(ScimRails.config.resource_group_schema, "RETRIEVED") if ScimRails.config.after_scim_response.respond_to?(:call)
 
       json_scim_response(object: nil)
     end

app/controllers/scim_rails/scim_schema_controller.rb

@@ -1,7 +1,7 @@
 module ScimRails
   class ScimSchemaController < ApplicationController
     def get_schema
-      ScimRails.config.before_scim_response.call(request.params) unless ScimRails.config.before_scim_response.nil?
+      ScimRails.config.before_scim_response.call(request.params) if ScimRails.config.before_scim_response.respond_to?(:call)
 
       id = request.params.key?("format") ? "#{request.params[:id]}.#{request.params[:format]}" : request.params[:id]
 
@@ -13,7 +13,7 @@ def get_schema
         object = {}
       end
 
-      ScimRails.config.after_scim_response.call(object, "RETRIEVED") unless ScimRails.config.after_scim_response.nil?
+      ScimRails.config.after_scim_response.call(object, "RETRIEVED") if ScimRails.config.after_scim_response.respond_to?(:call)
 
       json_schema_response(object)
     end