Timestamp columns of HABTM join table should record timestamps

[#5161 state:resolved]

activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb

@@ -53,7 +53,11 @@ def insert_record(record, force = true, validate = true)
                 when @reflection.association_foreign_key.to_s
                   attrs[relation[column.name]] = record.id
                 else
-                  if record.has_attribute?(column.name)
+                  if record.send(:all_timestamp_attributes).include?(column.name.to_sym)
+                    if record.record_timestamps
+                      attrs[relation[column.name]] = record.send(:current_time_from_proper_timezone)
+                    end
+                  elsif record.has_attribute?(column.name)
                     value = @owner.send(:quote_value, record[column.name], column)
                     attrs[relation[column.name]] = value unless value.nil?
                   end

activerecord/lib/active_record/timestamp.rb

@@ -39,8 +39,9 @@ def create #:nodoc:
       if record_timestamps
         current_time = current_time_from_proper_timezone
 
-        write_attribute('created_at', current_time) if respond_to?(:created_at) && created_at.nil?
-        write_attribute('created_on', current_time) if respond_to?(:created_on) && created_on.nil?
+        timestamp_attributes_for_create.each do |column|
+          write_attribute(column.to_s, current_time) if respond_to?(column) && self.send(column).nil?
+        end
 
         timestamp_attributes_for_update_in_model.each do |column|
           write_attribute(column.to_s, current_time) if self.send(column).nil?
@@ -65,7 +66,19 @@ def record_update_timestamps #:nodoc:
     end
 
     def timestamp_attributes_for_update_in_model #:nodoc:
-      [:updated_at, :updated_on].select { |elem| respond_to?(elem) }
+      timestamp_attributes_for_update.select { |elem| respond_to?(elem) }
+    end
+
+    def timestamp_attributes_for_update #:nodoc:
+      [:updated_at, :updated_on]
+    end
+
+    def timestamp_attributes_for_create #:nodoc:
+      [:created_at, :created_on]
+    end
+
+    def all_timestamp_attributes #:nodoc:
+      timestamp_attributes_for_update + timestamp_attributes_for_create
     end
     
     def current_time_from_proper_timezone #:nodoc:

activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb

@@ -85,7 +85,9 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :categories, :posts, :categories_posts, :developers, :projects, :developers_projects,
            :parrots, :pirates, :treasures, :price_estimates, :tags, :taggings
 
-  def test_should_property_quote_string_primary_keys
+  def setup_data_for_habtm_case
+    ActiveRecord::Base.connection.execute('delete from countries_treaties')
+
     country = Country.new(:name => 'India')
     country.country_id = 'c1'
     country.save!
@@ -93,6 +95,10 @@ def test_should_property_quote_string_primary_keys
     treaty = Treaty.new(:name => 'peace')
     treaty.treaty_id = 't1'
     country.treaties << treaty
+  end
+
+  def test_should_property_quote_string_primary_keys
+    setup_data_for_habtm_case
 
     con = ActiveRecord::Base.connection
     sql = 'select * from countries_treaties'
@@ -101,6 +107,33 @@ def test_should_property_quote_string_primary_keys
     assert_equal 't1', record[1]
   end
 
+  def test_should_record_timestamp_for_join_table
+    setup_data_for_habtm_case
+
+    con = ActiveRecord::Base.connection
+    sql = 'select * from countries_treaties'
+    record = con.select_rows(sql).last
+    assert_not_nil record[2]
+    assert_not_nil record[3]
+    assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[2]
+    assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[3]
+  end
+
+  def test_should_record_timestamp_for_join_table_only_if_timestamp_should_be_recorded
+    begin
+      Treaty.record_timestamps = false
+      setup_data_for_habtm_case
+
+      con = ActiveRecord::Base.connection
+      sql = 'select * from countries_treaties'
+      record = con.select_rows(sql).last
+      assert_nil record[2]
+      assert_nil record[3]
+    ensure
+      Treaty.record_timestamps = true
+    end
+  end
+
   def test_has_and_belongs_to_many
     david = Developer.find(1)
 

activerecord/test/schema/schema.rb

@@ -611,6 +611,8 @@ def create_table(*args, &block)
   create_table :countries_treaties, :force => true, :id => false do |t|
     t.string :country_id, :null => false
     t.string :treaty_id, :null => false
+    t.datetime :created_at
+    t.datetime :updated_at
   end
 
   except 'SQLite' do