some progress on has_one association testing. ran into wall trying to…

… replace an existing singular association.

lib/nested_assignment.rb

@@ -1,7 +1,13 @@
 # NestedAssignment
 module NestedAssignment
   def self.included(base)
-    base.class_eval { extend ClassMethods }
+    base.class_eval do
+      extend ClassMethods
+
+      alias_method_chain :save, :associated
+      alias_method_chain :valid?, :associated
+      alias_method_chain :changed?, :associated
+    end
   end
 
   module ClassMethods
@@ -12,7 +18,13 @@ def accessible_associations(*associations)
         define_method("#{name}_params=") do |hash|
           assoc = self.send(name)
           hash.values.each do |row|
-            record = row[:id].blank? ? assoc.build : assoc.select{|r| r.id == row[:id].to_i}
+            # TODO: need to bypass the replace() call inside singular associations (has_one and belongs_to). but they
+            # do serve a purpose: disassociating or destroying an existing record. if that is not to happen during
+            # assignment, then those records need to be collected for later disassociation (or removal, if :dependent
+            # => :destroy). that would need to be part of the saving process. ALSO, this makes sense to handle while
+            # deleting from plural associations. so perhaps instead of setting #_delete, i should add to a
+            # disassociation hash for later.
+            record = row[:id].blank? ? assoc.build : [assoc].flatten.detect{|r| r.id == row[:id].to_i}
             if row[:_delete]
               record._delete = true
             else
@@ -29,26 +41,30 @@ def association_names
     end
   end
 
-  # marks the record to be deleted in the next save
+  # marks the (associated) record to be deleted in the next deep save
   attr_accessor :_delete
 
   # deep validation of any changed (or new) records.
   # makes sure that any single invalid record will not halt the
   # validation process, so that all errors will be available
   # afterwards.
-  def valid?
-    [changed_associated.all?(&:valid?), super].all?
+  def valid_with_associated?
+    [changed_associated.all?(&:valid?), valid_without_associated?].all?
   end
 
   # deep saving of any new, changed, or deleted records.
-  def save
+  def save_with_associated
     self.class.transaction do
-      super
-      changed_associated.each(&:save)
-      deletable_associated.each(&:destroy)
+      changed_associated.all?(&:save) &&
+        deletable_associated.all?(&:destroy) &&
+        save_without_associated
     end
   end
 
+  def changed_with_associated?
+    changed_without_associated? or instantiated_associated.any?(&:changed?)
+  end
+
   protected
 
   def deletable_associated

test/db/models.rb

@@ -14,25 +14,37 @@ def self.included(base)
 
   class Address < ActiveRecord::Base
     belongs_to :addressable, :polymorphic => true
+
+    validates_presence_of :name
   end
 
   class User < ActiveRecord::Base
     has_and_belongs_to_many :roles
     has_one :subscription
     has_one :address, :as => :addressable
+
+    accessible_associations :subscription
+
+    validates_presence_of :name
   end
 
   class Service < ActiveRecord::Base
     has_many :subscriptions
     has_many :users, :through => :subscriptions
+
+    validates_presence_of :name
   end
 
   class Subscription < ActiveRecord::Base
     belongs_to :service
     belongs_to :user
+
+    validates_presence_of :name
   end
 
   class Role < ActiveRecord::Base
     has_and_belongs_to_many :users
+
+    validates_presence_of :name
   end
-end
+end

test/test_helper.rb

@@ -6,6 +6,10 @@
 require 'active_record'
 require 'active_record/fixtures'
 
+# load the code-to-be-tested
+ActiveSupport::Dependencies.load_paths << File.dirname(__FILE__) + '/../lib/'
+require File.dirname(__FILE__) + '/../init'
+
 # establish the database connection
 ActiveRecord::Base.configurations = YAML::load(IO.read(File.dirname(__FILE__) + '/db/database.yml'))
 ActiveRecord::Base.establish_connection('nested_assignment_test')
@@ -31,6 +35,3 @@ class ActiveSupport::TestCase
   fixtures :all
 end
 
-# load the code-to-be-tested
-ActiveSupport::Dependencies.load_paths << File.dirname(__FILE__) + '/../lib/'
-require File.dirname(__FILE__) + '/../init'

test/unit/nested_assignment_test.rb

@@ -2,8 +2,63 @@
 
 require 'ruby-debug'
 
-class NestedAssignmentTest < ActiveSupport::TestCase
+class NestedAssignmentHasOneTest < ActiveSupport::TestCase
+  def setup
+    @user = users(:bob)
+    @subscription = subscriptions(:bob_is_free)
+  end
+
+  def test_updating_a_subscription
+    @user.subscription_params = {
+      "1" => {
+        :id => @subscription.id,
+        :name => "Bobtastic"
+      }
+    }
+    assert !@user.subscription.new_record?, "the association was not rebuilt"
+    assert_equal "Bobtastic", @user.subscription.name, "the existing subscription's name has changed"
+    assert_equal "Bob/Free", @subscription.reload.name, "the name change has not been saved"
+  end
+
+  def test_assigning_a_replacement_subscription
+    @user.subscription_params = {
+      "1" => {
+        :name => "Bobtastic"
+      }
+    }
+    assert @user.subscription.new_record?, "the association is a new object"
+    assert_equal "Bobtastic", @user.subscription.name, "the new record has the specified name"
+    assert !@subscription.reload.user_id.nil?, "the previously associated object has not been disassociated yet"
+  end
+
+  def test_assigning_a_removed_subscription
+    @user.subscription_params = {
+      "1" => {
+        :id => @subscription.id,
+        :name => "Bobtastic",
+        :_delete => "1"
+      }
+    }
+    assert @user.subscription._delete, "the association is marked for deletion"
+    assert_nothing_raised("the associated object has not been deleted yet") do @subscription.reload end
+    assert_equal "Bob/Free", @user.subscription.name, "the association attribute did not update"
+  end
+
+end
+
+class NestedAssignmentBelongsToTest < ActiveSupport::TestCase
+end
+
+class NestedAssignmentHasManyTest < ActiveSupport::TestCase
+end
+
+class NestedAssignmentHasAndBelongsToManyTest < ActiveSupport::TestCase
+end
+
+class NestedAssignmentHasManyThroughTest < ActiveSupport::TestCase
+end
 
+class NestedAssignmentHelperTest < ActiveSupport::TestCase
   def test_association_names
     assert_equal [:address, :roles, :subscription], User.association_names.sort_by(&:to_s)
   end