Implement error handling

app/helpers/content_helper.rb

@@ -26,12 +26,15 @@ def expand_content_body(body)
     pattern =~ body
     data = Regexp.last_match
     if data && data.size == 5
-      article_ids = data[1..4].map { |str| str.to_i }
-      articles = article_ids.map { |id| Article.find(id) } # need rescue here, just return body
-      rendered_articles = render 'articles/shared/articles_grid', articles: articles
-      # the replace part
-      expanded_body = body.sub(pattern, rendered_articles)
-      expanded_body.html_safe
+      begin
+        article_ids = data[1..4].map { |str| str.to_i }
+        articles = Article.find(article_ids)
+        rendered_articles = render 'articles/shared/articles_grid', articles: articles
+        expanded_body = body.sub(pattern, rendered_articles)
+        expanded_body.html_safe
+      rescue ActiveRecord::RecordNotFound
+        body
+      end
     else
       body
     end

test/features/contents_test.rb

@@ -71,8 +71,8 @@
 
   scenario 'content with article previews gets rendered correctly' do
     # markup like
-    # [articles ids="1 2 3 4"]
-    # in content bodys is expanded to four article previews in a grid
+    #   [articles ids="1 2 3 4"]
+    # in content bodies is expanded to four article previews in a grid
     user = FactoryGirl.create(:user)
     article_ids = 4.times.map { FactoryGirl.create(:article, seller: user).id }
     content = FactoryGirl.create(:content,
@@ -83,4 +83,11 @@
     page.must_have_content 'Book 3'
     page.must_have_content 'Book 4'
   end
+
+  scenario 'content with article previews does not render if articles are missing' do
+    content = FactoryGirl.create(:content,
+                                 body: "<p>[articles ids=\"1 2 3 4\"]</p>")
+    visit content_path content
+    page.must_have_content '[articles ids="1 2 3 4"]'
+  end
 end