Implemented build and create for Factory

lib/factory_girl/factory.rb

@@ -12,19 +12,36 @@ class Factory
   # Arguments:
   #   name: (Symbol)
   #     A unique name used to identify this factory.
+  #   options: (Hash)
+  #     class: the class that will be used when generating instances for this
+  #            factory.
   #
   # Yields:
   #    The newly created factory (Factory)
-  def self.define (name)
-    instance = Factory.new(name)
+  def self.define (name, options = {})
+    instance = Factory.new(name, options)
     yield(instance)
     self.factories << instance
   end
 
-  def initialize (name) #:nodoc:
-    @name = name
+  # Calculates the class that should be instantiated by generation methods.
+  #
+  # If a class was passed when defining this factory, that class will be
+  # returned. Otherwise, the class will be guessed from the factory name.
+  #
+  # Returns:
+  #   The class that will be instantiated by generation methods.
+  def build_class
+    @build_class ||= @options[:class] || name.to_s.classify.constantize
+  end
+
+  def initialize (name, options = {}) #:nodoc:
+    options.assert_valid_keys(:class)
+    @name    = name
+    @options = options
+
     @static_attributes = {}
-    @lazy_attributes = {}
+    @lazy_attributes   = {}
   end
 
   # Adds an attribute that should be assigned or stubbed on generated instances for this factory.
@@ -72,4 +89,42 @@ class Factory
     result.update(attrs)
   end
 
+  # Generates and returns an instance from this factory. Attributes can be
+  # individually overridden by passing in a Hash of attribute => value pairs.
+  #
+  # Arguments:
+  #   attrs: (Hash)
+  #     See attributes
+  #
+  # Returns:
+  #   An instance of the class this factory generates, with generated
+  #   attributes assigned.
+  def build (attrs = {})
+    instance = build_class.new
+    attributes(attrs).each do |attr, value|
+      instance.send(:"#{attr}=", value)
+    end
+    instance
+  end
+
+  # Generates, saves, and returns an instance from this factory. Attributes can
+  # be individually overridden by passing in a Hash of attribute => value
+  # pairs.
+  #
+  # If the instance is not valid, an ActiveRecord::Invalid exception will be
+  # raised.
+  #
+  # Arguments:
+  #   attrs: (Hash)
+  #     See attributes
+  #
+  # Returns:
+  #   A saved instance of the class this factory generates, with generated
+  #   attributes assigned.
+  def create (attrs = {})
+    instance = build(attrs)
+    instance.save!
+    instance
+  end
+
 end

test/factory_test.rb

@@ -2,17 +2,37 @@ require(File.join(File.dirname(__FILE__), 'test_helper'))
 
 class FactoryTest < Test::Unit::TestCase
 
+  def self.should_instantiate_class
+
+    should "instantiate the build class" do
+      assert_kind_of @class, @instance
+    end
+
+    should "assign attributes on the instance" do
+      assert_equal @first_name, @instance.first_name
+      assert_equal @last_name,  @instance.last_name
+    end
+
+    should "override attributes using the passed hash" do
+      @value = 'Davis'
+      @instance = @factory.build(:first_name => @value)
+      assert_equal @value, @instance.first_name
+    end
+
+  end
+
   context "defining a factory" do
 
     setup do
       @name    = :user
       @factory = mock('factory')
+      @options = { :class => 'magic' }
       Factory.stubs(:new).returns(@factory)
     end
 
-    should "create a new factory" do
-      Factory.expects(:new).with(@name)
-      Factory.define(@name) {|f| }
+    should "create a new factory using the specified name and options" do
+      Factory.expects(:new).with(@name, @options)
+      Factory.define(@name, @options) {|f| }
     end
 
     should "pass the factory do the block" do
@@ -35,6 +55,7 @@ class FactoryTest < Test::Unit::TestCase
 
     setup do
       @name    = :user
+      @class   = User
       @factory = Factory.new(@name)
     end
 
@@ -42,6 +63,10 @@ class FactoryTest < Test::Unit::TestCase
       assert_equal @name, @factory.name
     end
 
+    should "have a build class" do
+      assert_equal @class, @factory.build_class
+    end
+
     context "when adding an attribute with a value parameter" do
 
       setup do
@@ -109,6 +134,68 @@ class FactoryTest < Test::Unit::TestCase
 
     end
 
+    should "guess the build class from the factory name" do
+      assert_equal User, @factory.build_class
+    end
+
+    context "when defined with a custom class" do
+
+      setup do
+        @class   = User
+        @factory = Factory.new(:author, :class => @class)
+      end
+
+      should "use the specified class as the build class" do
+        assert_equal @class, @factory.build_class
+      end
+
+    end
+
+    context "with some attributes added" do
+
+      setup do
+        @first_name = 'Billy'
+        @last_name  = 'Idol'
+        @email      = 'test@something.com'
+
+        @factory.add_attribute(:first_name, @first_name)
+        @factory.add_attribute(:last_name,  @last_name)
+        @factory.add_attribute(:email,      @email)
+      end
+
+      context "when building an instance" do
+
+        setup do
+          @instance = @factory.build
+        end
+
+        should_instantiate_class
+
+      end
+      
+      context "when creating an instance" do
+
+        setup do
+          User.delete_all
+          @instance = @factory.create
+        end
+
+        should_instantiate_class
+
+        should "save the instance" do
+          assert_equal 1, @class.count
+        end
+
+      end
+
+      should "raise an ActiveRecord::RecordInvalid error for invalid instances" do
+        assert_raise(ActiveRecord::RecordInvalid) do
+          @factory.create(:first_name => nil)
+        end
+      end
+
+    end
+
   end
 
 end