Fix Paranoia to work with validates_uniquness_of (rails3 branch)

lib/paranoia.rb

@@ -172,4 +172,18 @@ def paranoia_column
   end
 end
 
+
 require 'paranoia/rspec' if defined? RSpec
+
+module ActiveRecord
+  module Validations
+    class UniquenessValidator < ActiveModel::EachValidator
+      protected
+      def build_relation_with_paranoia(klass, table, attribute, value)
+        relation = build_relation_without_paranoia(klass, table, attribute, value)
+        relation.and(klass.quoted_table_name + ".#{klass.paranoia_column} IS NULL")
+      end
+      alias_method_chain :build_relation, :paranoia
+    end
+  end
+end

paranoia.gemspec

@@ -18,6 +18,7 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'bundler', '>= 1.0.0'
   s.add_development_dependency 'rake'
+  s.add_development_dependency 'test-unit'
 
   s.files = `git ls-files`.split("\n")
   s.executables = `git ls-files`.split("\n").map { |f| f =~ /^bin\/(.*)/ ? $1 : nil }.compact

test/paranoia_test.rb

@@ -16,7 +16,7 @@
 ActiveRecord::Base.connection.execute 'CREATE TABLE callback_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
 ActiveRecord::Base.connection.execute 'CREATE TABLE fail_callback_models (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
 ActiveRecord::Base.connection.execute 'CREATE TABLE related_models (id INTEGER NOT NULL PRIMARY KEY, parent_model_id INTEGER NOT NULL, deleted_at DATETIME)'
-ActiveRecord::Base.connection.execute 'CREATE TABLE employers (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
+ActiveRecord::Base.connection.execute 'CREATE TABLE employers (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME, name VARCHAR(10))'
 ActiveRecord::Base.connection.execute 'CREATE TABLE employees (id INTEGER NOT NULL PRIMARY KEY, deleted_at DATETIME)'
 ActiveRecord::Base.connection.execute 'CREATE TABLE jobs (id INTEGER NOT NULL PRIMARY KEY, employer_id INTEGER NOT NULL, employee_id INTEGER NOT NULL, deleted_at DATETIME)'
 ActiveRecord::Base.connection.execute 'CREATE TABLE custom_column_models (id INTEGER NOT NULL PRIMARY KEY, destroyed_at DATETIME)'
@@ -434,6 +434,13 @@ def test_observers_not_notified_if_not_supported
     a.restore!
     # essentially, we're just ensuring that this doesn't crash
   end
+
+  def test_validates_uniqueness_only_checks_non_deleted_records
+    a = Employer.create!(name: "A")
+    a.destroy
+    b = Employer.new(name: "A")
+    assert b.valid?
+  end
 
   private
   def get_featureful_model
@@ -498,6 +505,7 @@ class RelatedModel < ActiveRecord::Base
 
 class Employer < ActiveRecord::Base
   acts_as_paranoid
+  validates_uniqueness_of :name
   has_many :jobs
   has_many :employees, :through => :jobs
 end