Tag Aliases: automatically remove redundant implications

app/models/tag_alias.rb

@@ -2,7 +2,7 @@ class TagAlias < TagRelationship
   validates_uniqueness_of :antecedent_name, scope: :status, conditions: -> { active }
   validate :absence_of_transitive_relation
 
-  before_create :delete_conflicting_alias
+  before_create :delete_conflicting_relationships
 
   def self.to_aliased(names)
     names = Array(names).map(&:to_s)
@@ -37,8 +37,12 @@ class TagAlias < TagRelationship
 
   # Allow aliases to be reversed. If A -> B already exists, but we're trying to
   # create B -> A, then automatically delete A -> B so we can make B -> A.
-  def delete_conflicting_alias
-    tag_alias = TagAlias.active.find_by(antecedent_name: consequent_name, consequent_name: antecedent_name)
-    tag_alias.reject! if tag_alias.present?
+  # Also automatically remove implications that are being replaced by aliases
+  def delete_conflicting_relationships
+    tag_relationships = []
+    tag_relationships << TagAlias.active.find_by(antecedent_name: consequent_name, consequent_name: antecedent_name)
+    tag_relationships << TagImplication.active.find_by(antecedent_name: antecedent_name, consequent_name: consequent_name)
+    tag_relationships << TagImplication.active.find_by(antecedent_name: consequent_name, consequent_name: antecedent_name)
+    tag_relationships.each { |rel| rel.reject! if rel.present? }
   end
 end

test/unit/tag_alias_test.rb

@@ -286,5 +286,12 @@ class TagAliasTest < ActiveSupport::TestCase
       assert_equal(4, tag1.reload.category)
       assert_equal(3, tag2.reload.category)
     end
+
+    should "automatically remove a redundant implication" do
+      ti = create(:tag_implication, antecedent_name: "new_asuka", consequent_name: "asuka", status: "active")
+      create(:tag_alias, antecedent_name: "new_asuka", consequent_name: "asuka", status: "active")
+
+      assert_equal("deleted", ti.reload.status)
+    end
   end
 end