add failing test that shows Paranoia not working with validates_uniquness_of

test/paranoia_test.rb

@@ -28,7 +28,7 @@ def setup!
     'fail_callback_models' => 'deleted_at DATETIME',
     'related_models' => 'parent_model_id INTEGER, parent_model_with_counter_cache_column_id INTEGER, deleted_at DATETIME',
     'asplode_models' => 'parent_model_id INTEGER, deleted_at DATETIME',
-    'employers' => 'deleted_at DATETIME',
+    'employers' => 'name VARCHAR(32), deleted_at DATETIME',
     'employees' => 'deleted_at DATETIME',
     'jobs' => 'employer_id INTEGER NOT NULL, employee_id INTEGER NOT NULL, deleted_at DATETIME',
     'custom_column_models' => 'destroyed_at DATETIME',
@@ -685,6 +685,13 @@ class ParanoiaTest < test_framework
     # 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
+
   def test_i_am_the_destroyer
     expected = %Q{
       Sharon: "There should be a method called I_AM_THE_DESTROYER!"
@@ -909,6 +916,7 @@ end
 
 class Employer < ActiveRecord::Base
   acts_as_paranoid
+  validates_uniqueness_of :name
   has_many :jobs
   has_many :employees, :through => :jobs
 end