Support binding a block to multiple callbacks

This allows for binding multiple callbacks (after_stub, before_create,
etc.) to a single block. This is useful if you want a block to be called
across all build strategies (since build_stubbed doesn't share any
callbacks with build/create).

Examples:

    factory :user do
      callback(:after_stub, :before_create) { do_something }
      after(:stub, :create) { do_something_else }
      before(:create, :custom) { do_a_third_thing }
    end

GETTING_STARTED.md

@@ -714,6 +714,16 @@ Calling FactoryGirl.create will invoke both `after_build` and `after_create` cal
 
 Also, like standard attributes, child factories will inherit (and can also define) callbacks from their parent factory.
 
+Multiple callbacks can be assigned to run a block; this is useful when building various strategies that run the same code (since there are no callbacks that are shared across all strategies).
+
+```ruby
+factory :user do
+  callback(:after_stub, :before_create) { do_something }
+  after(:stub, :create) { do_something_else }
+  before(:create, :custom) { do_a_third_thing }
+end
+```
+
 Modifying factories
 -------------------
 

lib/factory_girl/definition_proxy.rb

@@ -158,17 +158,19 @@ module FactoryGirl
       @definition.define_constructor(&block)
     end
 
-    def before(name, &block)
-      callback("before_#{name}", &block)
+    def before(*names, &block)
+      callback(*names.map {|name| "before_#{name}" }, &block)
     end
 
-    def after(name, &block)
-      callback("after_#{name}", &block)
+    def after(*names, &block)
+      callback(*names.map {|name| "after_#{name}" }, &block)
     end
 
-    def callback(name, &block)
-      FactoryGirl.register_callback(name)
-      @definition.add_callback(Callback.new(name, block))
+    def callback(*names, &block)
+      names.each do |name|
+        FactoryGirl.register_callback(name)
+        @definition.add_callback(Callback.new(name, block))
+      end
     end
   end
 end

spec/acceptance/callbacks_spec.rb

@@ -149,3 +149,29 @@ describe "custom callbacks" do
     FactoryGirl.totally_custom(:user).name.should == "Totally Custom"
   end
 end
+
+describe 'binding a callback to multiple callbacks' do
+  before do
+    define_model('User', name: :string)
+
+    FactoryGirl.define do
+      factory :user do
+        callback(:before_create, :after_stub) do |instance|
+          instance.name = instance.name.upcase
+        end
+      end
+    end
+  end
+
+  it 'binds the callback to creation' do
+    FactoryGirl.create(:user, name: 'John Doe').name.should == 'JOHN DOE'
+  end
+
+  it 'does not bind the callback to building' do
+    FactoryGirl.build(:user, name: 'John Doe').name.should == 'John Doe'
+  end
+
+  it 'binds the callback to stubbing' do
+    FactoryGirl.build_stubbed(:user, name: 'John Doe').name.should == 'JOHN DOE'
+  end
+end

spec/factory_girl/definition_proxy_spec.rb

@@ -140,6 +140,24 @@ describe FactoryGirl::DefinitionProxy, "adding callbacks" do
     before { proxy.after(:stub, &callback) }
     it     { should have_callback(:after_stub).with_block(callback) }
   end
+
+  context "#after(:stub, :create)" do
+    before { proxy.after(:stub, :create, &callback) }
+    it     { should have_callback(:after_stub).with_block(callback) }
+    it     { should have_callback(:after_create).with_block(callback) }
+  end
+
+  context "#before(:stub, :create)" do
+    before { proxy.before(:stub, :create, &callback) }
+    it     { should have_callback(:before_stub).with_block(callback) }
+    it     { should have_callback(:before_create).with_block(callback) }
+  end
+
+  context "#callback(:after_stub, :before_create)" do
+    before { proxy.callback(:after_stub, :before_create, &callback) }
+    it     { should have_callback(:after_stub).with_block(callback) }
+    it     { should have_callback(:before_create).with_block(callback) }
+  end
 end
 
 describe FactoryGirl::DefinitionProxy, "#to_create" do