Fix for Rails 7

README.rdoc

@@ -14,6 +14,10 @@ Version 2.5.3 is based on Rails 3.0.0 and uses all of the new ActiveModel/Active
 
 Version 3.0.0 is based on Rails 3.2.12 and tested against Ruby 1.9.3-p385. 3.0.0 fixes issues with the ActiveRecord method connected? being overwritten by acts-as-dag. Thanks to Ryan Glover (@ersatzryan) for the patch.
 
+Version 4.0.0 is based and tested on Rails 5.2 to 6.1, ruby 2.6 and 2.7
+
+Version 4.1.0 adds support for Rails 7
+
 === What's a DAG?
 
 http://en.wikipedia.org/wiki/Directed_acyclic_graph

lib/acts-as-dag/version.rb

@@ -1,7 +1,7 @@
 module Acts
   module As
     module Dag
-      VERSION = "4.0.0"
+      VERSION = "4.1.0"
     end
   end
 end

lib/dag/validators.rb

@@ -4,12 +4,12 @@ module Dag
   class CreateCorrectnessValidator < ActiveModel::Validator
 
     def validate(record)
-      record.errors[:base] << 'Link already exists between these points' if has_duplicates(record)
-      record.errors[:base] << 'Link already exists in the opposite direction' if has_long_cycles(record)
-      record.errors[:base] << 'Link must start and end in different places' if has_short_cycles(record)
+      record.errors.add(:base, 'Link already exists between these points') if has_duplicates(record)
+      record.errors.add(:base, 'Link already exists in the opposite direction') if has_long_cycles(record)
+      record.errors.add(:base, 'Link must start and end in different places') if has_short_cycles(record)
       cnt = check_possible(record)
-      record.errors[:base] << 'Cannot create a direct link with a count other than 0' if cnt == 1
-      record.errors[:base] << 'Cannot create an indirect link with a count less than 1' if cnt == 2
+      record.errors.add(:base, 'Cannot create a direct link with a count other than 0') if cnt == 1
+      record.errors.add(:base, 'Cannot create an indirect link with a count less than 1') if cnt == 2
     end
 
     private
@@ -39,9 +39,9 @@ def check_possible(record)
   class UpdateCorrectnessValidator < ActiveModel::Validator
 
     def validate(record)
-      record.errors[:base] << "No changes" unless record.changed?
-      record.errors[:base] << "Do not manually change the count value" if manual_change(record)
-      record.errors[:base] << "Cannot make a direct link with count 1 indirect" if direct_indirect(record)
+      record.errors.add(:base, "No changes") unless record.changed?
+      record.errors.add(:base, "Do not manually change the count value") if manual_change(record)
+      record.errors.add(:base, "Cannot make a direct link with count 1 indirect") if direct_indirect(record)
     end
 
     private