Don't error when deleting supplier/group with already existing deleted name (closes foodcoops/foodsoft#197)

app/models/concerns/mark_as_deleted_with_name.rb

@@ -0,0 +1,25 @@
+module MarkAsDeletedWithName
+  extend ActiveSupport::Concern
+
+  def mark_as_deleted
+    # get maximum length of name
+    max_length = 100000
+    if lenval = self.class.validators_on(:name).detect { |v| v.is_a?(ActiveModel::Validations::LengthValidator) }
+      max_length = lenval.options[:maximum]
+    end
+    # find unique deleted name
+    # (would have been nice to use retry, but there is no general duplicate-entry exception)
+    n = ''
+    begin
+      append = ' \u2020' + n
+      deleted_name = name.truncate(max_length-append.length, omission: '') + append
+      if n.blank?
+        n = 'A'
+      else
+        n.succ!
+      end
+    end while self.class.where(name: deleted_name).exists?
+    # mark as deleted
+    update_columns deleted_at: Time.now, name: deleted_name
+  end
+end

app/models/group.rb

@@ -1,6 +1,9 @@
+# encoding: utf-8
 # Groups organize the User.
 # A Member gets the roles from the Group
 class Group < ActiveRecord::Base
+  include MarkAsDeletedWithName
+
   has_many :memberships, dependent: :destroy
   has_many :users, :through => :memberships
 
@@ -32,8 +35,8 @@ class Group < ActiveRecord::Base
     # TODO: Checks for participating in not closed orders
     transaction do
       memberships.destroy_all
-      # TODO: What should happen to users?
-      update_column :deleted_at, Time.now
+      # @todo what should happen to the users?
+      super
     end
   end
 end

app/models/supplier.rb

@@ -1,5 +1,7 @@
 # encoding: utf-8
 class Supplier < ActiveRecord::Base
+  include MarkAsDeletedWithName
+
   has_many :articles, -> { where(:type => nil).includes(:article_category).order('article_categories.name', 'articles.name') }
   has_many :stock_articles, -> { includes(:article_category).order('article_categories.name', 'articles.name') }
   has_many :orders
@@ -109,7 +111,7 @@ class Supplier < ActiveRecord::Base
 
   def mark_as_deleted
     transaction do
-      update_column :deleted_at, Time.now
+      super
       articles.each(&:mark_as_deleted)
     end
   end