From 7ab279a534fbc01af22b8fd406f185e55b6d5c70 Mon Sep 17 00:00:00 2001
From: Fabio Rehm <fgrehm@gmail.com>
Date: Sun, 11 Mar 2012 20:43:00 -0300
Subject: [PATCH] Does not try to set attributes on initialization if provided
 argument is nil

---
 lib/virtus/instance_methods.rb                |  2 +-
 .../instance_methods/initialize_spec.rb       | 32 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 spec/unit/virtus/instance_methods/initialize_spec.rb

diff --git a/lib/virtus/instance_methods.rb b/lib/virtus/instance_methods.rb
index 58f1f8f4..8d480854 100644
--- a/lib/virtus/instance_methods.rb
+++ b/lib/virtus/instance_methods.rb
@@ -12,7 +12,7 @@ module InstanceMethods
     #
     # @api private
     def initialize(attribute_values = {})
-      self.attributes = attribute_values
+      self.attributes = attribute_values if attribute_values
     end
 
     # Returns a value of the attribute with the given name
diff --git a/spec/unit/virtus/instance_methods/initialize_spec.rb b/spec/unit/virtus/instance_methods/initialize_spec.rb
new file mode 100644
index 00000000..0957c668
--- /dev/null
+++ b/spec/unit/virtus/instance_methods/initialize_spec.rb
@@ -0,0 +1,32 @@
+require 'spec_helper'
+
+describe Virtus::InstanceMethods, '#initialize' do
+  let(:described_class) do
+    Class.new do
+      include Virtus
+      attribute :name, String
+    end
+  end
+
+  let(:subject) do
+    described_class.new(attributes)
+  end
+
+  context "with valid argument" do
+    let(:attributes) do
+      {:name => 'john'}
+    end
+
+    it 'sets attributes' do
+      subject.name.should == attributes[:name]
+    end
+  end
+
+  context "with nil argument" do
+    let(:attributes) { nil }
+
+    it 'does not try to set attributes' do
+      expect { subject }.to_not raise_error(NoMethodError)
+    end
+  end
+end