Adds tests to subfolder internal oneboxing

Test if the local onebox engine works fine when using a sulbfolder install

spec/components/onebox/engine/discourse_local_onebox_spec.rb

@@ -94,4 +94,61 @@ describe Onebox::Engine::DiscourseLocalOnebox do
       expect(html).to eq("<video width='100%' height='100%' controls><source src='#{url}'><a href='#{url}'>#{url}</a></video>")
     end
   end
+  
+  context "When deployed to a subfolder" do
+    let(:base_url) { "http://test.localhost/subfolder" }
+    let(:base_uri) { "/subfolder" }
+
+    before do
+      Discourse.stubs(:base_url).returns(base_url)
+      Discourse.stubs(:base_uri).returns(base_uri)
+    end
+
+    it "matches for a topic url" do
+      url = "#{Discourse.base_url}/t/hot-topic"
+      expect(Onebox.has_matcher?(url)).to eq(true)
+      expect(Onebox::Matcher.new(url).oneboxed).to eq(described_class)
+    end
+
+    it "matches for a post url" do
+      url = "#{Discourse.base_url}/t/hot-topic/23/2"
+      expect(Onebox.has_matcher?(url)).to eq(true)
+      expect(Onebox::Matcher.new(url).oneboxed).to eq(described_class)
+    end
+
+    context "for a link to a post" do
+      let(:post)  { Fabricate(:post) }
+      let(:post2) { Fabricate(:post, topic: post.topic, post_number: 2) }
+
+      it "returns a link if post isn't found" do
+        url = "#{Discourse.base_url}/t/not-exist/3/2"
+        expect(Onebox.preview(url).to_s).to eq("<a href='#{url}'>#{url}</a>")
+      end
+
+      it "returns a link if not allowed to see the post" do
+        url = "#{Discourse.base_url}#{post2.url}"
+        Guardian.any_instance.stubs(:can_see?).returns(false)
+        expect(Onebox.preview(url).to_s).to eq("<a href='#{url}'>#{url}</a>")
+      end
+
+      it "returns a link if post is hidden" do
+        hidden_post = Fabricate(:post, topic: post.topic, post_number: 2, hidden: true, hidden_reason_id: Post.hidden_reasons[:flag_threshold_reached])
+        url = "#{Discourse.base_url}#{hidden_post.url}"
+        expect(Onebox.preview(url).to_s).to eq("<a href='#{url}'>#{url}</a>")
+      end
+
+      it "returns some onebox goodness if post exists and can be seen" do
+        url = "#{Discourse.base_url}#{post2.url}?source_topic_id=#{post2.topic_id+1}"
+        Guardian.any_instance.stubs(:can_see?).returns(true)
+        html = Onebox.preview(url).to_s
+        expect(html).to include(post2.excerpt)
+        expect(html).to include(post2.topic.title)
+
+        url = "#{Discourse.base_url}#{post2.url}"
+        html = Onebox.preview(url).to_s
+        expect(html).to include(post2.user.username)
+        expect(html).to include(post2.excerpt)
+      end
+    end
+  end
 end