Plain HTML "templates", with ERB layout, from Sinatra

gistfile1.rb

class MySinatraApplication < Sinatra::Base
  get "/some-mockup-path" do
    html :somemockup
  end

  helpers do
    def html(template, options = {}, locals = {})
      render :html, template, options, locals
    end

    def compile_template(engine, data, options, views)
      return super(:erb, data, options, views) if data == :layout

      case engine
      when :html
        template = Object.new
        template.instance_variable_set :@data, data

        def template.render(scope, locals = {})
          view_path = File.join(settings.views, "#{@data}.html")
          File.read(view_path)
        end

        template
      else
        super
      end
    end
  end
end

If this ends up being good for my workflow, I'll either write a Tilt/Sinatra extension to do this right, or submit patches