add support for front-matter

closes #4

lib/index.coffee

@@ -2,6 +2,9 @@ marked = require 'marked'
 Entities = require('html-entities').AllHtmlEntities
 indent = require 'indent'
 pad = require 'pad'
+yaml = require 'js-yaml'
+fm = require 'front-matter'
+
 
 htmlEntities = new Entities()
 
@@ -185,12 +188,18 @@ fixHeaders = (ast) ->
   return ast
 
 module.exports = (dirtyMarkdown) ->
-  ast = marked.lexer(dirtyMarkdown)
+  out = []
+
+  # handle yaml front-matter
+  content = fm(dirtyMarkdown)
+  if Object.keys(content.attributes).length isnt 0
+    out.push '---', yaml.safeDump(content.attributes).trim(), '---\n'
+
+  ast = marked.lexer(content.body)
 
   # see issue: https://github.com/chjj/marked/issues/472
   links = ast.links
 
-  out = []
   previousToken = undefined
 
   # remove all the `space` and `list_end` tokens - they're useless

package.json

@@ -7,8 +7,10 @@
     "tidy-markdown": "./bin/index.js"
   },
   "dependencies": {
+    "front-matter": "^1.0.0",
     "html-entities": "^1.0.10",
     "indent": "0.0.1",
+    "js-yaml": "^3.2.7",
     "marked": "^0.3.2",
     "pad": "0.0.5"
   },

test/index.coffee

@@ -294,6 +294,23 @@ describe 'html', ->
       </dl>
     ''')
 
+
+describe 'front-matter', ->
+  it 'should handle front-matter', ->
+    tidyMdSnippet('''
+      ---
+      title: "Awesome markdown file"
+      ---
+      My content
+    ''').should.equal('''
+      ---
+      title: Awesome markdown file
+      ---
+
+      My content
+    ''')
+
+
 describe 'full documents', ->
   it 'should reformat to match expected', ->
     for file in fs.readdirSync('./test/cases')