closes #9779 Auto-require haml/erb/builder/sass

this is causing thread-saftey issues.

README.rdoc

@@ -118,6 +118,9 @@ any strings passed to them directly.
 
 The haml gem/library is required to render HAML templates:
 
+  ## You'll need to require haml in your app
+  require 'haml'
+
   get '/' do
     haml :index
   end
@@ -138,6 +141,9 @@ and overridden on an individual basis.
 
 === Erb Templates
 
+  ## You'll need to require erb in your app
+  require 'erb'
+
   get '/' do
     erb :index
   end
@@ -148,6 +154,9 @@ Renders <tt>./views/index.erb</tt>
 
 The builder gem/library is required to render builder templates:
 
+  ## You'll need to require builder in your app
+  require 'builder'
+
   get '/' do
     content_type 'application/xml', :charset => 'utf-8'
     builder :index
@@ -159,6 +168,9 @@ Renders <tt>./views/index.builder</tt>.
 
 The sass gem/library is required to render Sass templates:
 
+  ## You'll need to require haml or sass in your app
+  require 'sass'
+
   get '/stylesheet.css' do
     content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet

compat/helper.rb

@@ -1,6 +1,10 @@
 require 'rubygems'
 require 'mocha'
 
+require 'haml'
+require 'sass'
+require 'builder'
+
 # disable warnings in compat specs.
 $VERBOSE = nil
 

lib/sinatra/base.rb

@@ -223,23 +223,19 @@ module Sinatra
   #                 in the template
   module Templates
     def erb(template, options={}, locals={})
-      require 'erb' unless defined? ::ERB
       render :erb, template, options, locals
     end
 
     def haml(template, options={}, locals={})
-      require 'haml' unless defined? ::Haml::Engine
       render :haml, template, options, locals
     end
 
     def sass(template, options={}, locals={})
-      require 'sass' unless defined? ::Sass::Engine
       options[:layout] = false
       render :sass, template, options, locals
     end
 
     def builder(template=nil, options={}, locals={}, &block)
-      require 'builder' unless defined? ::Builder
       options, template = template, nil if template.is_a?(Hash)
       template = lambda { block } if template.nil?
       render :builder, template, options, locals

test/haml_test.rb

@@ -1,4 +1,5 @@
 require File.dirname(__FILE__) + '/helper'
+require 'haml'
 
 class HAMLTest < Test::Unit::TestCase
   def haml_app(&block)

test/helper.rb

@@ -14,6 +14,10 @@ $LOAD_PATH.unshift libdir unless $LOAD_PATH.include?(libdir)
 require 'contest'
 require 'sinatra/test'
 
+require 'haml'
+require 'sass'
+require 'builder'
+
 class Sinatra::Base
   # Allow assertions in request context
   include Test::Unit::Assertions