Added an exception when defining a sequence from a dynamic attribute block [#43 state:resolved]

lib/factory_girl/attribute/dynamic.rb

@@ -2,14 +2,17 @@ class Factory
   class Attribute #:nodoc:
 
     class Dynamic < Attribute  #:nodoc:
-
       def initialize(name, block)
         super(name)
         @block = block
       end
 
       def add_to(proxy)
-        proxy.set(name, @block.call(proxy))
+        value = @block.call(proxy)
+        if Factory::Sequence === value
+          raise SequenceAbuseError
+        end
+        proxy.set(name, value)
       end
     end
 

lib/factory_girl/sequence.rb

@@ -1,5 +1,8 @@
 class Factory
 
+  # Raised when calling Factory.sequence from a dynamic attribute block
+  class SequenceAbuseError < StandardError; end
+
   # Sequences are defined using Factory.sequence. Sequence values are generated
   # using next.
   class Sequence

spec/factory_girl/attribute/dynamic_spec.rb

@@ -33,6 +33,16 @@ describe Factory::Attribute::Dynamic do
     }.should raise_error(Factory::AttributeDefinitionError)
   end
 
+  it "should raise an error when returning a sequence" do
+    stub(Factory).sequence { Factory::Sequence.new }
+    block = lambda { Factory.sequence(:email) }
+    attr = Factory::Attribute::Dynamic.new(:email, block)
+    proxy = stub!.set.subject
+    lambda {
+      attr.add_to(proxy)
+    }.should raise_error(Factory::SequenceAbuseError)
+  end
+
   it "should convert names to symbols" do
     Factory::Attribute::Dynamic.new('name', nil).name.should == :name
   end

spec/integration_spec.rb

@@ -1,7 +1,6 @@
 require File.expand_path(File.join(File.dirname(__FILE__), 'spec_helper'))
 
 describe "integration" do
-
   before do
     Factory.define :user, :class => 'user' do |f|
       f.first_name 'Jimi'
@@ -23,6 +22,10 @@ describe "integration" do
       f.email { Factory.next(:email) }
     end
 
+    Factory.define :sequence_abuser, :class => User do |f|
+      f.first_name { Factory.sequence(:email) }
+    end
+
     Factory.define :guest, :parent => :user do |f|
       f.last_name 'Anonymous'
       f.username  'GuestUser'
@@ -233,4 +236,9 @@ describe "integration" do
     end
   end
 
+  it "should raise Factory::SequenceAbuseError" do
+    lambda {
+      Factory(:sequence_abuser)
+    }.should raise_error(Factory::SequenceAbuseError)
+  end
 end