test: Improve test suite setup

spec/dummy/db/seeds.rb

@@ -7,7 +7,8 @@ end
 (11..20).each do |i|
   age = 21 + 3 * (i - 10)
   attrs = { name: "Author #{i}", age: age, email: "some@email#{i}.com" }
-  Author.find_or_create_by!(attrs) do |author|
+  Author.find_or_create_by!(name: "Author #{i}") do |author|
+    author.assign_attributes(attrs)
     author.profile = Profile.new(description: "Profile description for Author #{i}") if (i % 3).zero?
   end
 end
@@ -19,6 +20,8 @@ tags = Tag.where.not(name: 'A test tag').pluck(:id)
     title: "Post #{i}",
     author_id: authors.sample,
     position: rand(100),
+    summary: "<p><em>Summary</em> for post #{i}</p>",
+    description: "<p><strong>Some bold</strong> <em>Some italic</em> <u>Some underline</u> [#{i}]</p>",
     created_at: Time.now - rand(3600).seconds
   }
   attrs[:category] = 'news' if (i % 4).zero?