Rails view helper for stripping whitespace between elements. Very useful for using `display: inline-block`.

application_helper.rb

module ApplicationHelper
  def inline_tag(*args, &block)
    body = Nokogiri::HTML(capture(&block)).at_css('body')

    # First-level text nodes
    body.xpath('text()').each do |node|
      node.content = node.content.strip
    end

    content_tag(*args) { body.inner_html.strip.html_safe }
  end
end

index.html.erb

<header>
  <h1>Foozle</h1>
  <nav>
    <%= inline_tag :ul, style: 'outline: 2px solid pink' do %>
      <li>Foo</li>
      <li>Baz <b>Twiz</b> Miz</li>
      <li>Fiz</li>
    <% end %>
  </nav>
</header>

result.html

<header>
  <h1>Foozle</h1>
  <nav>
    <ul style="outline: 2px solid pink"><li>Foo</li><li>Baz <b>Twiz</b> Miz</li><li>Fiz</li></ul>    </nav>
</header>