Support markdown filter via tilt

fast_haml.gemspec

@@ -31,6 +31,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "haml"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rake-compiler"
+  spec.add_development_dependency "redcarpet"
   spec.add_development_dependency "rspec", ">= 3"
   spec.add_development_dependency "sass"
   spec.add_development_dependency "simplecov"

lib/fast_haml/filter_compilers.rb

@@ -33,6 +33,7 @@ def self.find(name)
 require 'fast_haml/filter_compilers/css'
 require 'fast_haml/filter_compilers/escaped'
 require 'fast_haml/filter_compilers/javascript'
+require 'fast_haml/filter_compilers/markdown'
 require 'fast_haml/filter_compilers/plain'
 require 'fast_haml/filter_compilers/preserve'
 require 'fast_haml/filter_compilers/ruby'

lib/fast_haml/filter_compilers/markdown.rb

@@ -0,0 +1,18 @@
+require 'fast_haml/filter_compilers/tilt_base'
+
+module FastHaml
+  module FilterCompilers
+    class Markdown < TiltBase
+      def need_newline?
+        false
+      end
+
+      def compile(texts)
+        temple = [:multi, [:newline]]
+        compile_with_tilt(temple, 'markdown', texts)
+      end
+    end
+
+    register(:markdown, Markdown)
+  end
+end

spec/render/filters/markdown_spec.rb

@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+RSpec.describe 'Markdown filter rendering', type: :render do
+  it 'renders Markdown filter' do
+    expect(render_string(<<HAML)).to eq("<h1>hello</h1>\nworld\n")
+:markdown
+  # hello
+world
+HAML
+  end
+
+  it 'parses string interpolation' do
+    expect(render_string(<<'HAML')).to eq("<h1>hello</h1>\nworld\n")
+:markdown
+  # #{'hello'}
+world
+HAML
+  end
+end