Show merged stories on duplicate submission

app/views/stories/_form_errors.html.erb

@@ -2,7 +2,7 @@
   <div class="form_errors_header">
     <% if story.errors.any? %>
       <%= errors_for story %>
-    <% elsif !story.errors.any? && story.public_similar_stories(@user).any? %>
+    <% elsif !story.errors.any? && story.similar_stories.any? %>
       <div class="flash-notice">
         <h2>Note: This story was already submitted <%= time_ago_in_words_label(story.most_recent_similar.created_at) %></h2>
         <p>
@@ -20,7 +20,7 @@
       <% end %>
     <% end %>
 
-    <% if story.public_similar_stories(@user).any? %>
+    <% if story.similar_stories.any? %>
       <p>Previous discussions for this story:</p>
       <%= render partial: "stories/similar", locals: { similar: story.similar_stories } %>
     <% end %>

app/views/stories/_similar.html.erb

@@ -2,6 +2,9 @@
   <% similar.each do |story| %>
     <li>
       <a href="<%= story.url %>" target="_blank"><%= story.title %></a>
+      <% if story.merged_story_id %>
+        (merged into <a href="<%= story.merged_into_story.url %>" target="_blank"><%= story.merged_into_story.title %></a>)
+      <% end %>
       <%= story.user_is_author? ? "authored by" : "via" %>
       <%= styled_user_link story.user, story %>
       <%= time_ago_in_words_label(story.created_at) %>

spec/requests/stories_spec.rb

@@ -10,6 +10,42 @@ describe "stories", type: :request do
   describe "#check_url_dupe" do
     before { sign_in user }
 
+    context "html" do
+      it "returns an error when story URL is missing" do
+        expect {
+          post "/stories/check_url_dupe.html", params: {story: {url: ""}}
+        }.to raise_error(ActionController::ParameterMissing)
+      end
+
+      it "returns previous discussions for an existing story" do
+        post "/stories/check_url_dupe.html", params: {story: {url: story.url}}
+
+        expect(response).to be_successful
+
+        expect(response.body).to include("Previous discussions for this story")
+        expect(response.body).to include(story.title)
+        expect(response.body).to include(story.url)
+
+        expect(response.body).not_to include("merged into")
+      end
+
+      it "returns a story merged into an existing one" do
+        merged_story = create(:story, merged_story_id: story.id)
+
+        post "/stories/check_url_dupe.html", params: {story: {url: merged_story.url}}
+
+        expect(response).to be_successful
+
+        expect(response.body).to include("Previous discussions for this story")
+        expect(response.body).to include(merged_story.title)
+        expect(response.body).to include(merged_story.url)
+
+        expect(response.body).to include("merged into")
+        expect(response.body).to include(story.title)
+        expect(response.body).to include(story.url)
+      end
+    end
+
     context "json" do
       it "returns similar story matching URL" do
         post "/stories/check_url_dupe.json",