Add create_association! for belongs_to

activerecord/lib/active_record/associations.rb

@@ -1534,9 +1534,9 @@ module ActiveRecord
         def association_constructor_methods(reflection)
           constructors = {
             "build_#{reflection.name}"   => "build",
-            "create_#{reflection.name}" => "create"
+            "create_#{reflection.name}"  => "create",
+            "create_#{reflection.name}!" => "create!"
           }
-          constructors["create_#{reflection.name}!"] = "create!" if reflection.macro == :has_one
 
           constructors.each do |name, proxy_name|
             redefine_method(name) do |*params|

activerecord/lib/active_record/associations/belongs_to_association.rb

@@ -6,6 +6,10 @@ module ActiveRecord
         replace(@reflection.create_association(attributes))
       end
 
+      def create!(attributes = {})
+        build(attributes).tap { |record| record.save! }
+      end
+
       def build(attributes = {})
         replace(@reflection.build_association(attributes))
       end

activerecord/test/cases/associations/belongs_to_associations_test.rb

@@ -120,6 +120,23 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal apple.name, client.firm_name
   end
 
+  def test_create!
+    client  = Client.create!(:name => "Jimmy")
+    account = client.create_account!(:credit_limit => 10)
+    assert_equal account, client.account
+    assert account.persisted?
+    client.save
+    client.reload
+    assert_equal account, client.account
+  end
+
+  def test_failing_create!
+    client  = Client.create!(:name => "Jimmy")
+    assert_raise(ActiveRecord::RecordInvalid) { client.create_account! }
+    assert_not_nil client.account
+    assert client.account.new_record?
+  end
+
   def test_natural_assignment_to_nil
     client = Client.find(3)
     client.firm = nil

activerecord/test/models/company.rb

@@ -124,6 +124,7 @@ class Client < Company
   belongs_to :firm_with_primary_key_symbols, :class_name => "Firm", :primary_key => :name, :foreign_key => :firm_name
   belongs_to :readonly_firm, :class_name => "Firm", :foreign_key => "firm_id", :readonly => true
   has_many :accounts, :through => :firm
+  belongs_to :account
 
   # Record destruction so we can test whether firm.clients.clear has
   # is calling client.destroy, deleting from the database, or setting

activerecord/test/schema/schema.rb

@@ -154,6 +154,7 @@ ActiveRecord::Schema.define do
     t.string  :name
     t.integer :client_of
     t.integer :rating, :default => 1
+    t.integer :account_id
   end
 
   add_index :companies, [:firm_id, :type, :rating, :ruby_type], :name => "company_index"