Implicitly call FactoryGirl's syntax methods from dynamic attributes

lib/factory_girl.rb

@@ -28,6 +28,7 @@ require 'factory_girl/aliases'
 require 'factory_girl/definition'
 require 'factory_girl/definition_proxy'
 require 'factory_girl/syntax'
+require 'factory_girl/syntax_runner'
 require 'factory_girl/find_definitions'
 require 'factory_girl/reload'
 require 'factory_girl/version'

lib/factory_girl/attribute_assigner.rb

@@ -1,6 +1,7 @@
 module FactoryGirl
   class AttributeAssigner
-    def initialize(evaluator, &instance_builder)
+    def initialize(evaluator, build_class, &instance_builder)
+      @build_class = build_class
       @instance_builder         = instance_builder
       @evaluator                = evaluator
       @attribute_list           = evaluator.class.attribute_list
@@ -18,7 +19,7 @@ module FactoryGirl
     end
 
     def hash
-      @evaluator.instance = NullObject.new
+      @evaluator.instance = build_hash
 
       attributes_to_set_on_hash.inject({}) do |result, attribute|
         result[attribute] = get(attribute)
@@ -32,6 +33,10 @@ module FactoryGirl
       @build_class_instance ||= @evaluator.instance_exec(&@instance_builder)
     end
 
+    def build_hash
+      @build_hash ||= NullObject.new(hash_instance_methods_to_respond_to)
+    end
+
     def get(attribute_name)
       @evaluator.send(attribute_name)
     end
@@ -64,6 +69,10 @@ module FactoryGirl
       @evaluator.__overrides.keys
     end
 
+    def hash_instance_methods_to_respond_to
+      @attribute_list.map(&:name) + override_names + @build_class.instance_methods
+    end
+
     def alias_names_to_ignore
       @attribute_list.reject(&:ignored).map do |attribute|
         override_names.map {|override| attribute.name if attribute.alias_for?(override) && attribute.name != override && !ignored_attribute_names.include?(override) }

lib/factory_girl/evaluator.rb

@@ -47,7 +47,11 @@ module FactoryGirl
       if @cached_attributes.key?(method_name)
         @cached_attributes[method_name]
       else
-        @instance.send(method_name, *args, &block)
+        if @instance.respond_to?(method_name)
+          @instance.send(method_name, *args, &block)
+        else
+          SyntaxRunner.new.send(method_name, *args, &block)
+        end
       end
     end
 

lib/factory_girl/factory.rb

@@ -33,7 +33,7 @@ module FactoryGirl
       strategy = strategy_class.new
 
       evaluator = evaluator_class.new(strategy, overrides.symbolize_keys)
-      attribute_assigner = AttributeAssigner.new(evaluator, &instance_builder)
+      attribute_assigner = AttributeAssigner.new(evaluator, build_class, &instance_builder)
 
       evaluation = Evaluation.new(attribute_assigner, to_create)
       evaluation.add_observer(CallbackRunner.new(callbacks, evaluator))

lib/factory_girl/null_object.rb

@@ -1,7 +1,19 @@
 module FactoryGirl
   class NullObject < ::BasicObject
-    def method_missing(*args)
-      nil
+    def initialize(methods_to_respond_to)
+      @methods_to_respond_to = methods_to_respond_to.map(&:to_s)
+    end
+
+    def method_missing(name, *args, &block)
+      if respond_to?(name)
+        nil
+      else
+        super
+      end
+    end
+
+    def respond_to?(method, include_private=false)
+      @methods_to_respond_to.include? method.to_s
     end
   end
 end

lib/factory_girl/syntax_runner.rb

@@ -0,0 +1,5 @@
+module FactoryGirl
+  class SyntaxRunner
+    include Syntax::Methods
+  end
+end

spec/acceptance/syntax_methods_within_dynamic_attributes_spec.rb

@@ -0,0 +1,41 @@
+require "spec_helper"
+
+describe "syntax methods within dynamic attributes" do
+  before do
+    define_model("Post", title: :string, user_id: :integer) do
+      belongs_to :user
+
+      def generate
+        "generate result"
+      end
+    end
+    define_model("User", email: :string)
+
+    FactoryGirl.define do
+      sequence(:email_address) {|n| "person-#{n}@example.com" }
+
+      factory :user do
+        email { generate(:email_address) }
+      end
+
+      factory :post do
+        title { generate }
+        user { build(:user) }
+      end
+    end
+  end
+
+  it "can access syntax methods from dynamic attributes" do
+    FactoryGirl.build(:user).email.should == "person-1@example.com"
+    FactoryGirl.attributes_for(:user)[:email].should == "person-2@example.com"
+  end
+
+  it "can access syntax methods from dynamic attributes" do
+    FactoryGirl.build(:post).user.should be_instance_of(User)
+  end
+
+  it "can access methods already existing on the class" do
+    FactoryGirl.build(:post).title.should == "generate result"
+    FactoryGirl.attributes_for(:post)[:title].should be_nil
+  end
+end

spec/factory_girl/null_object_spec.rb

@@ -1,8 +1,22 @@
 require "spec_helper"
 
 describe FactoryGirl::NullObject do
-  its(:id)     { should be_nil }
-  its(:age)    { should be_nil }
-  its(:name)   { should be_nil }
-  its(:admin?) { should be_nil }
+  let(:methods_to_respond_to)     { %w[id age name admin?] }
+  let(:methods_to_not_respond_to) { %w[email date_of_birth title] }
+
+  subject { FactoryGirl::NullObject.new(methods_to_respond_to) }
+
+  it "responds to the given methods" do
+    methods_to_respond_to.each do |method_name|
+      subject.__send__(method_name).should be_nil
+      subject.respond_to?(method_name).should be_true
+    end
+  end
+
+  it "does not respond to other methods" do
+    methods_to_not_respond_to.each do |method_name|
+      expect { subject.__send__(method_name) }.to raise_error(NoMethodError)
+      subject.respond_to?(method_name).should be_false
+    end
+  end
 end