From 9b7ecc0012f0c7959c41ece3776a426c40293cd5 Mon Sep 17 00:00:00 2001
From: Justin Coyne <justin@curationexperts.com>
Date: Mon, 26 Jan 2015 22:27:22 -0600
Subject: [PATCH] Don't attempt to remove a non-existant variable

---
 lib/ldp/response.rb           | 10 ++++----
 spec/lib/ldp/response_spec.rb | 43 +++++++++++++++++++++++------------
 2 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/lib/ldp/response.rb b/lib/ldp/response.rb
index 7e62b2b..25e5cd4 100644
--- a/lib/ldp/response.rb
+++ b/lib/ldp/response.rb
@@ -63,10 +63,12 @@ def self.rdf_source? response
     def dup
       super.tap do |new_resp|
         new_resp.send(:extend, Ldp::Response)
-        if ::RUBY_VERSION < '2.0'
-          new_resp.send(:remove_instance_variable, :@graph)
-        else
-          new_resp.remove_instance_variable(:@graph)
+        unless new_resp.instance_variable_get(:@graph).nil?
+          if ::RUBY_VERSION < '2.0'
+            new_resp.send(:remove_instance_variable, :@graph)
+          else
+            new_resp.remove_instance_variable(:@graph)
+          end
         end
       end
     end
diff --git a/spec/lib/ldp/response_spec.rb b/spec/lib/ldp/response_spec.rb
index 4c2bf46..dd89ebf 100644
--- a/spec/lib/ldp/response_spec.rb
+++ b/spec/lib/ldp/response_spec.rb
@@ -19,29 +19,44 @@
   end
 
   describe "#dup" do
-    let(:simple_container_graph) { "<> a <http://www.w3.org/ns/ldp#Container> ." }
-    let(:link) { ["<http://www.w3.org/ns/ldp#Resource>;rel=\"type\"","<http://www.w3.org/ns/ldp#BasicContainer>;rel=\"type\""] }
-
+    let(:mock_conn) { Faraday.new { |builder| builder.adapter :test, conn_stubs } }
+    let(:client) { Ldp::Client.new mock_conn }
+    let(:raw_response) { client.get "a_container" }
     let(:conn_stubs) do
       Faraday::Adapter::Test::Stubs.new do |stub|
-        stub.get('/a_container') { [200, {"Link" => link}, simple_container_graph] }
+        stub.get('/a_container') { [200, {"Link" => link}, body] }
       end
     end
-
-    let(:mock_conn) { Faraday.new { |builder| builder.adapter :test, conn_stubs } }
-    let(:client) { Ldp::Client.new mock_conn }
-    let(:raw_response) { client.get "a_container" }
-
     let(:response) { Ldp::Response.wrap mock_client, raw_response }
+
     subject { response.dup }
-    it { is_expected.to respond_to :links }
 
-    it "should not have duplicated the graph" do
-      expect(response.graph.object_id).not_to eq subject.graph.object_id
+    context "for a container resource" do
+      let(:body) { "<> a <http://www.w3.org/ns/ldp#Container> ." }
+      let(:link) { ["<http://www.w3.org/ns/ldp#Resource>;rel=\"type\"","<http://www.w3.org/ns/ldp#BasicContainer>;rel=\"type\""] }
+      it { is_expected.to respond_to :links }
+
+      it "should not have duplicated the graph" do
+        expect(response.graph.object_id).not_to eq subject.graph.object_id
+      end
+
+      it "should have duplicated the body" do
+        expect(response.body.object_id).to eq subject.body.object_id
+      end
     end
 
-    it "should have duplicated the body" do
-      expect(response.body.object_id).to eq subject.body.object_id
+    context "for a non-rdf resource" do
+      let(:body) { "This is only a test" }
+      let(:link) { ["<http://www.w3.org/ns/ldp#Resource>;rel=\"type\"","<http://www.w3.org/ns/ldp#NonRDFSource>;rel=\"type\""] }
+      it { is_expected.to respond_to :links }
+
+      it "should not have a graph" do
+        expect(response.instance_variable_get(:@graph)).to be_nil
+      end
+
+      it "should have duplicated the body" do
+        expect(response.body.object_id).to eq subject.body.object_id
+      end
     end
   end