複数のABテストを同時に行う多変量テストを hacker-friendly な記法で簡単に実装できる gem を開発中。
下記のように記述できる。

home/index.html.erb

...

<div class="landing-image">
  <% # The first test %>
  <%= select_variation(:landing_page, :btn_color, "red_btn", "green_btn", "blue_btn") do |alt| %>
    <% # alt will be "red", "green" or "blue" %>
    <%= link_to next_page_path, "Next", :class => alt %>
  <% end %>
</div>

...

<div class="content">
  ...

  <% # And the second one. You can also change what template is rendered by doing like this. %>
  <%= select_variation(:landing_page, :explanation, "alts/explain1", "alts/explain2") do |alt| %>
      <%= render :partial => alt %>
  <% end %>
  ...

  <% # You can put as many ab tests as you want in one page! %>
  <%= link_to select_variation(:landing_page, :signup, "Learn more", "Sign up"), signup_path %>
  <% # This is the same as the code below. %>
  <% # select_variation(:landing_page, :signup, "Learn more", "Sign up") do |alt| %>
    <% # link_to alt, signup_path %>
  <% # end %>
  ...

</div>

...

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