From 1000f20504e47e0b73d717b2799750c57b735c4e Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Mon, 30 Mar 2015 17:39:20 +0900
Subject: [PATCH] Add markdown filter

---
 hamlit.gemspec                       |  1 +
 lib/hamlit/compilers/filter.rb       |  2 ++
 lib/hamlit/filters/markdown.rb       | 11 +++++++++++
 lib/hamlit/filters/tilt.rb           | 28 ++++++++++++++++++----------
 lib/hamlit/parser.rb                 |  1 +
 spec/hamlit/filters/markdown_spec.rb | 28 ++++++++++++++++++++++++++++
 6 files changed, 61 insertions(+), 10 deletions(-)
 create mode 100644 lib/hamlit/filters/markdown.rb
 create mode 100644 spec/hamlit/filters/markdown_spec.rb

diff --git a/hamlit.gemspec b/hamlit.gemspec
index 32a1a46f..dde2b342 100644
--- a/hamlit.gemspec
+++ b/hamlit.gemspec
@@ -29,6 +29,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "less"
   spec.add_development_dependency "pry"
   spec.add_development_dependency "rake"
+  spec.add_development_dependency "redcarpet"
   spec.add_development_dependency "rspec", ">= 3"
   spec.add_development_dependency "sass"
   spec.add_development_dependency "slim"
diff --git a/lib/hamlit/compilers/filter.rb b/lib/hamlit/compilers/filter.rb
index afd34153..b94f0b5f 100644
--- a/lib/hamlit/compilers/filter.rb
+++ b/lib/hamlit/compilers/filter.rb
@@ -8,6 +8,7 @@ require 'hamlit/filters/plain'
 require 'hamlit/filters/preserve'
 require 'hamlit/filters/ruby'
 require 'hamlit/filters/sass'
+require 'hamlit/filters/markdown'
 require 'hamlit/filters/scss'
 
 module Hamlit
@@ -24,6 +25,7 @@ module Hamlit
         register :escaped,    Filters::Escaped
         register :javascript, Filters::Javascript
         register :less,       Filters::Less
+        register :markdown,   Filters::Markdown
         register :plain,      Filters::Plain
         register :preserve,   Filters::Preserve
         register :ruby,       Filters::Ruby
diff --git a/lib/hamlit/filters/markdown.rb b/lib/hamlit/filters/markdown.rb
new file mode 100644
index 00000000..348fc70a
--- /dev/null
+++ b/lib/hamlit/filters/markdown.rb
@@ -0,0 +1,11 @@
+require 'hamlit/filters/tilt'
+
+module Hamlit
+  module Filters
+    class Markdown < Filters::Tilt
+      def compile(lines)
+        compile_with_tilt('markdown', lines.join("\n"), [], indent_width: 0)
+      end
+    end
+  end
+end
diff --git a/lib/hamlit/filters/tilt.rb b/lib/hamlit/filters/tilt.rb
index 3d1c6d47..2b30e7d6 100644
--- a/lib/hamlit/filters/tilt.rb
+++ b/lib/hamlit/filters/tilt.rb
@@ -7,25 +7,33 @@ module Hamlit
     class Tilt < Filters::Base
       include Concerns::StringInterpolation
 
-      def self.render(name, source)
+      def self.render(name, source, indent_width: 2)
         result = ::Tilt["t.#{name}"].new { source }.render
-        indent_source(result, indent_width: 2)
+        indent_source(result, indent_width: indent_width)
       end
 
       private
 
-      def compile_with_tilt(name, source, ast)
-        return runtime_compile(name, source, ast) if contains_interpolation?(source)
+      def compile_with_tilt(name, source, ast, indent_width: 2)
+        if contains_interpolation?(source)
+          return runtime_compile(name, source, ast, indent_width: indent_width)
+        end
 
-        result  = [:static, Filters::Tilt.render(name, source)]
-        content = [:multi, [:static, "\n"], result]
-        ast << content
+        content = [:static, Filters::Tilt.render(name, source, indent_width: indent_width)]
+        build_ast(ast, content)
       end
 
-      def runtime_compile(name, source, ast)
+      def runtime_compile(name, source, ast, indent_width: 2)
         literal = string_literal(source)
-        code    = "::Hamlit::Filters::Tilt.render(#{name.inspect}, #{literal})"
-        content = [:multi, [:static, "\n"], [:dynamic, code]]
+        code    = "::Hamlit::Filters::Tilt.render(#{name.inspect}, #{literal}, indent_width: #{indent_width})"
+        content = [:dynamic, code]
+        build_ast(ast, content)
+      end
+
+      def build_ast(ast, content)
+        return content if ast.empty?
+
+        content = [:multi, [:static, "\n"], content]
         ast << content
       end
     end
diff --git a/lib/hamlit/parser.rb b/lib/hamlit/parser.rb
index 34daa832..c63c6608 100644
--- a/lib/hamlit/parser.rb
+++ b/lib/hamlit/parser.rb
@@ -112,6 +112,7 @@ module Hamlit
       SKIP_NEWLINE_EXPS.include?(ast.first) ||
         (ast[0..1] == [:haml, :doctype]) ||
         (ast[0..2] == [:haml, :filter, 'ruby']) ||
+        (ast[0..2] == [:haml, :filter, 'markdown']) ||
         @outer_removal.include?(@current_indent)
     end
   end
diff --git a/spec/hamlit/filters/markdown_spec.rb b/spec/hamlit/filters/markdown_spec.rb
new file mode 100644
index 00000000..d693ec53
--- /dev/null
+++ b/spec/hamlit/filters/markdown_spec.rb
@@ -0,0 +1,28 @@
+describe Hamlit::Filters::Markdown do
+  describe '#compile' do
+    it 'renders markdown filter' do
+      assert_render(<<-HAML, <<-HTML)
+        :markdown
+          # Hamlit
+          Yet another haml implementation
+      HAML
+        <h1>Hamlit</h1>
+
+        <p>Yet another haml implementation</p>
+      HTML
+    end
+
+    it 'renders markdown filter with string interpolation' do
+      assert_render(<<-'HAML', <<-HTML)
+        - project = 'Hamlit'
+        :markdown
+          # #{project}
+          Yet another haml implementation
+      HAML
+        <h1>Hamlit</h1>
+
+        <p>Yet another haml implementation</p>
+      HTML
+    end
+  end
+end