A sample of Sinatra + Slim

app.rb

# [Sinatra Recipes - Views - Slim](http://recipes.sinatrarb.com/p/views/slim)
#
# .
# ├── Gemfile
# ├── Gemfile.lock
# ├── app.rb
# └── views/
#     ├── index.slim
#     └── layout.slim

require 'sinatra'           # http://sinatrarb.com
require 'sinatra/reloader'  # http://sinatrarb.com/contrib/reloader
require 'slim'              # http://slim-lang.com

get '/' do
  @message = 'Hello!'
  slim :index
end

Gemfile

# frozen_string_literal: true

source 'https://rubygems.org'

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem 'sinatra'
gem 'sinatra-contrib'
gem 'slim'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    backports (3.15.0)
    multi_json (1.13.1)
    mustermann (1.0.3)
    rack (2.0.7)
    rack-protection (2.0.5)
      rack
    sinatra (2.0.5)
      mustermann (~> 1.0)
      rack (~> 2.0)
      rack-protection (= 2.0.5)
      tilt (~> 2.0)
    sinatra-contrib (2.0.5)
      backports (>= 2.8.2)
      multi_json
      mustermann (~> 1.0)
      rack-protection (= 2.0.5)
      sinatra (= 2.0.5)
      tilt (>= 1.3, < 3)
    slim (4.0.1)
      temple (>= 0.7.6, < 0.9)
      tilt (>= 2.0.6, < 2.1)
    temple (0.8.1)
    tilt (2.0.9)

PLATFORMS
  ruby

DEPENDENCIES
  sinatra
  sinatra-contrib
  slim

BUNDLED WITH
   2.0.1

index.slim

h1
  = @message

layout.slim

doctype html
html
  head
    title
      | A sample of Sinatra + Slim
    link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,300italic,700,700italic"
    link rel="stylesheet" href="https://cdn.rawgit.com/necolas/normalize.css/master/normalize.css"
    link rel="stylesheet" href="https://cdn.rawgit.com/milligram/milligram/master/dist/milligram.min.css"
  body class="container"
    == yield