fix #similar_stories to not include merged stories

app/models/story.rb

@@ -219,8 +219,14 @@ class Story < ApplicationRecord
     return [] unless self.url.present?
 
     @_similar_stories ||= Story.find_similar_by_url(self.url).order("id DESC")
+    # do not include this story itself or any story merged into it
     if self.id?
       @_similar_stories = @_similar_stories.where.not(id: self.id)
+        .where('merged_story_id is null or merged_story_id != ?', self.id)
+    end
+    # do not include the story this one is merged into
+    if self.merged_story_id?
+      @_similar_stories = @_similar_stories.where('id != ?', self.merged_story_id)
     end
     @_similar_stories
   end

spec/models/story_spec.rb

@@ -174,4 +174,20 @@ describe Story do
     expect(mod_log.action).to match(/title from "blah" to "changed title"/)
     expect(mod_log.action).to match(/tags from "tag1 tag2" to "tag1"/)
   end
+
+  describe "#similar_stories" do
+    it "finds stories with similar URLs" do
+      s1 = create(:story, url: 'https://example.com', created_at: (Story::RECENT_DAYS + 1).days.ago)
+      s2 = create(:story, url: 'https://example.com/')
+      expect(s1.similar_stories).to eq([s2])
+      expect(s2.similar_stories).to eq([s1])
+    end
+
+    it "does not include merges" do
+      s1 = create(:story, url: 'https://example.com', created_at: (Story::RECENT_DAYS + 1).days.ago)
+      s2 = create(:story, url: 'https://example.com/', merged_story_id: s1.id)
+      expect(s1.similar_stories).to eq([])
+      expect(s2.similar_stories).to eq([])
+    end
+  end
 end