Modified define_list_strategy_method to accept and use a block.

lib/factory_girl/strategy_syntax_method_registrar.rb

@@ -23,8 +23,8 @@ module FactoryGirl
     def define_list_strategy_method
       strategy_name = @strategy_name
 
-      define_syntax_method("#{strategy_name}_list") do |name, amount, *traits_and_overrides|
-        amount.times.map { send(strategy_name, name, *traits_and_overrides) }
+      define_syntax_method("#{strategy_name}_list") do |name, amount, *traits_and_overrides, &block|
+        amount.times.map { send(strategy_name, name, *traits_and_overrides, &block) }
       end
     end
 

spec/acceptance/build_list_spec.rb

@@ -2,11 +2,12 @@ require 'spec_helper'
 
 describe "build multiple instances" do
   before do
-    define_model('Post', title: :string)
+    define_model('Post', title: :string, position: :integer)
 
     FactoryGirl.define do
       factory(:post) do |post|
         post.title "Through the Looking Glass"
+        post.position { rand(10**4) }
       end
     end
   end
@@ -38,4 +39,18 @@ describe "build multiple instances" do
       end
     end
   end
+
+  context "with a block" do
+    subject do
+      FactoryGirl.build_list(:post, 20, title: "The Listing of the Block") do |post|
+        post.position = post.id
+      end
+    end
+
+    it "correctly uses the set value" do
+      subject.each_with_index do |record, index|
+        record.position.should == record.id
+      end
+    end
+  end
 end

spec/acceptance/create_list_spec.rb

@@ -2,11 +2,12 @@ require 'spec_helper'
 
 describe "create multiple instances" do
   before do
-    define_model('Post', title: :string)
+    define_model('Post', title: :string, position: :integer)
 
     FactoryGirl.define do
       factory(:post) do |post|
         post.title "Through the Looking Glass"
+        post.position { rand(10**4) }
       end
     end
   end
@@ -38,6 +39,20 @@ describe "create multiple instances" do
       end
     end
   end
+
+  context "with a block" do
+    subject do
+      FactoryGirl.create_list(:post, 20, title: "The Listing of the Block") do |post|
+        post.position = post.id
+      end
+    end
+
+    it "uses the new values" do
+      subject.each_with_index do |record, index|
+        record.position.should == record.id
+      end
+    end
+  end
 end
 
 describe "multiple creates and ignored attributes to dynamically build attribute lists" do