Cleanup articles cache busting (#13467)

* Extract repeated calls to cache_bust.call to iteration over list

This mirrors what the EdgeCache::BustUser service looks like.

It might make sense to have cached_article_paths be a method accepting
a block and yielding paths, and including the collections cache paths
as well.

* Move article path information into a separate method

BustArticle.call now only knows to bust cache for each path associated
with the article, the information about which paths to clear is moved
to a separate `paths_for` method.

I may have gone overboard on this.

* Remove extra blank line

app/services/edge_cache/bust_article.rb

@@ -14,23 +14,37 @@ module EdgeCache
 
       cache_bust = EdgeCache::Bust.new
 
-      cache_bust.call(article.path)
-      cache_bust.call("/#{article.user.username}")
-      cache_bust.call("#{article.path}/")
-      cache_bust.call("#{article.path}?i=i")
-      cache_bust.call("#{article.path}/?i=i")
-      cache_bust.call("#{article.path}/comments")
-      cache_bust.call("#{article.path}?preview=#{article.password}")
-      cache_bust.call("#{article.path}?preview=#{article.password}&i=i")
-      cache_bust.call("/#{article.organization.slug}") if article.organization.present?
+      paths_for(article) do |path|
+        cache_bust.call(path)
+      end
+
       bust_home_pages(cache_bust, article)
       bust_tag_pages(cache_bust, article)
-      cache_bust.call("/api/articles/#{article.id}")
+    end
+
+    def self.paths_for(article)
+      paths = [
+        article.path,
+        "/#{article.user.username}",
+        "#{article.path}/",
+        "#{article.path}?i=i",
+        "#{article.path}/?i=i",
+        "#{article.path}/comments",
+        "#{article.path}?preview=#{article.password}",
+        "#{article.path}?preview=#{article.password}&i=i",
+        "/api/articles/#{article.id}",
+      ]
+
+      paths.each do |path|
+        yield path
+      end
+
+      yield "/#{article.organization.slug}" if article.organization.present?
 
       return unless article.collection_id
 
       article.collection.articles.find_each do |collection_article|
-        cache_bust.call(collection_article.path)
+        yield collection_article.path
       end
     end