diff --git a/test/badges.js b/test/badges.js
new file mode 100644
index 0000000..9183031
--- /dev/null
+++ b/test/badges.js
@@ -0,0 +1,23 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('badges', function () {
+  var $
+
+  before(function () {
+    $ = marky(fixtures.badges)
+  })
+
+  it('adds a badge class to img tags containing badge images', function () {
+    assert($('img').length)
+    assert.equal($('img').length, $('img.badge').length)
+  })
+
+  it('adds a badge-only class to p tags containing nothing more than a badge', function () {
+    assert.equal($('p:not(.badge-only)').length, 2)
+    assert.equal($('p.badge-only').length, $('p').length - 2)
+  })
+})
diff --git a/test/cdn.js b/test/cdn.js
new file mode 100644
index 0000000..fbd78ac
--- /dev/null
+++ b/test/cdn.js
@@ -0,0 +1,73 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('cdn', function () {
+  describe('when serveImagesWithCDN is true', function () {
+    var $
+    var options = {
+      package: {name: 'foo', version: '1.0.0'},
+      serveImagesWithCDN: true
+    }
+
+    before(function () {
+      $ = marky(fixtures.basic, options)
+    })
+
+    it('replaces relative img URLs with npm CDN URLs', function () {
+      assert(~fixtures.basic.indexOf('![](relative.png)'))
+      assert($("img[src='https://cdn.npm.im/foo@1.0.0/relative.png']").length)
+    })
+
+    it('replaces slashy relative img URLs with npm CDN URLs', function () {
+      assert(~fixtures.basic.indexOf('![](/slashy/deep.png)'))
+      assert($("img[src='https://cdn.npm.im/foo@1.0.0/slashy/deep.png']").length)
+    })
+
+    it('leaves protocol relative URLs alone', function () {
+      assert(~fixtures.basic.indexOf('![](//protocollie.com/woof.png)'))
+      assert($("img[src='//protocollie.com/woof.png']").length)
+    })
+
+    it('leaves HTTPS URLs alone', function () {
+      assert(~fixtures.basic.indexOf('![](https://secure.com/good.png)'))
+      assert($("img[src='https://secure.com/good.png']").length)
+    })
+  })
+
+  describe('when serveImagesWithCDN is false (default)', function () {
+    var $
+    var options = {
+      package: {
+        name: 'foo',
+        version: '1.0.0'
+      }
+    }
+
+    before(function () {
+      $ = marky(fixtures.basic, options)
+    })
+
+    it('leaves relative img alone', function () {
+      assert(~fixtures.basic.indexOf('![](relative.png)'))
+      assert($("img[src='relative.png']").length)
+    })
+
+    it('leaves slashy relative img URLs alone', function () {
+      assert(~fixtures.basic.indexOf('![](/slashy/deep.png)'))
+      assert($("img[src='/slashy/deep.png']").length)
+    })
+
+    it('leaves protocol relative URLs alone', function () {
+      assert(~fixtures.basic.indexOf('![](//protocollie.com/woof.png)'))
+      assert($("img[src='//protocollie.com/woof.png']").length)
+    })
+
+    it('leaves HTTPS URLs alone', function () {
+      assert(~fixtures.basic.indexOf('![](https://secure.com/good.png)'))
+      assert($("img[src='https://secure.com/good.png']").length)
+    })
+  })
+})
diff --git a/test/fixtures.js b/test/fixtures.js
index 6c7c674..86958f2 100644
--- a/test/fixtures.js
+++ b/test/fixtures.js
@@ -1,6 +1,7 @@
 var fs = require('fs')
 var path = require('path')
 var glob = require('glob')
+var pkg = require('../package.json')
 
 var fixtures = {
   dependencies: [], // our dependencies and devDependencies
@@ -16,8 +17,8 @@ fs.readdirSync(__dirname + '/fixtures').forEach(function (file) {
 })
 
 // Read in dependencies' and devDependencies' readmes
-fixtures.dependencies = Object.keys(require('../package.json').devDependencies)
-  .concat(Object.keys(require('../package.json').dependencies))
+fixtures.dependencies = Object.keys(pkg.devDependencies)
+  .concat(Object.keys(pkg.dependencies))
   .sort()
 fixtures.dependencies.forEach(function (name) {
   var modulePath = path.resolve('node_modules', name)
diff --git a/test/github.js b/test/github.js
new file mode 100644
index 0000000..372cb06
--- /dev/null
+++ b/test/github.js
@@ -0,0 +1,6 @@
+/* globals describe */
+
+describe('github', function () {
+  require('./repo-github')
+  require('./repo-other')
+})
diff --git a/test/gravatar.js b/test/gravatar.js
new file mode 100644
index 0000000..6008c70
--- /dev/null
+++ b/test/gravatar.js
@@ -0,0 +1,29 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('gravatar', function () {
+  var $
+
+  before(function () {
+    $ = marky(fixtures.gravatar)
+  })
+
+  it('replaces insecure gravatar img src URLs with secure HTTPS URLs', function () {
+    assert(~fixtures.gravatar.indexOf('http://gravatar.com/avatar/123?s=50&d=retro'))
+    assert.equal($('img').length, 3)
+    assert.equal($('img').eq(0).attr('src'), 'https://secure.gravatar.com/avatar/123?s=50&d=retro')
+  })
+
+  it('leaves secure gravatar URLs untouched', function () {
+    assert(~fixtures.gravatar.indexOf('https://secure.gravatar.com/avatar/456?s=50&d=retro'))
+    assert.equal($('img').eq(1).attr('src'), 'https://secure.gravatar.com/avatar/456?s=50&d=retro')
+  })
+
+  it('leaves non-gravtar URLs untouched', function () {
+    assert(~fixtures.gravatar.indexOf('http://not-gravatar.com/foo'))
+    assert.equal($('img').eq(2).attr('src'), 'http://not-gravatar.com/foo')
+  })
+})
diff --git a/test/headings.js b/test/headings.js
new file mode 100644
index 0000000..55ac429
--- /dev/null
+++ b/test/headings.js
@@ -0,0 +1,97 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('headings', function () {
+  var $
+
+  before(function () {
+    $ = marky(fixtures.dirty)
+  })
+
+  it('injects hashy anchor tags into headings that have DOM ids', function () {
+    assert(~fixtures.dirty.indexOf('# h1'))
+    assert($("h1 a[href='#h1']").length)
+  })
+
+  it('adds deep-link class to modified headings', function () {
+    assert(~fixtures.dirty.indexOf('# h1'))
+    assert($("h1.deep-link a[href='#h1']").length)
+  })
+
+  it("doesn't inject anchor tags into headings that already contain anchors", function () {
+    assert(~fixtures.dirty.indexOf('### [h3](/already/linky)'))
+    assert($("h3 a[href='/already/linky']").length)
+  })
+
+  it('applies a prefix to generated DOM ids by default', function () {
+    assert(~fixtures.dirty.indexOf('## h2'))
+    assert.equal($('h2#user-content-h2').length, 1)
+  })
+
+  it('allows id prefixes to be disabled with prefixHeadingIds', function () {
+    assert(~fixtures.dirty.indexOf('#### This is a TEST'))
+    $ = marky(fixtures.dirty, {prefixHeadingIds: false})
+    assert.equal($('h4#this-is-a-test').length, 1)
+  })
+
+  it('allows a dash in generated DOM ids just like GitHub', function () {
+    assert(~fixtures.github.indexOf('### heading with a - dash'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#heading-with-a---dash a').length, 1)
+  })
+
+  it('allows a trailing dash in generated DOM ids just like GitHub', function () {
+    assert(~fixtures.github.indexOf('### heading with a trailing dash -'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#heading-with-a-trailing-dash-- a').length, 1)
+  })
+
+  it('allows underscores in generated DOM ids like GitHub', function () {
+    assert(~fixtures.github.indexOf('### heading with an _ underscore'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#heading-with-an-_-underscore a').length, 1)
+  })
+
+  it('filters periods in generated DOM ids like GitHub', function () {
+    assert(~fixtures.github.indexOf('### heading with a period.txt'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#heading-with-a-periodtxt').length, 1)
+  })
+
+  it('allows two spaces even after filtering like GitHub', function () {
+    assert(~fixtures.github.indexOf('### exchange.bind_headers(exchange, routing [, bindCallback])'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#exchangebind_headersexchange-routing--bindcallback').length, 1)
+  })
+
+  it('add suffix to duplicate generated DOM ids like GitHub', function () {
+    assert(~fixtures.github.indexOf('### duplicate'))
+    assert(~fixtures.github.indexOf('### duplicate('))
+    assert(~fixtures.github.indexOf('### duplicate)'))
+    $ = marky(fixtures.github)
+    assert.equal($('h3#duplicate a').length, 1)
+    assert.equal($('h3#duplicate-1 a').length, 1)
+    assert.equal($('h3#duplicate-2 a').length, 1)
+  })
+
+  it('encodes innerHTML and removes angle brackets before generating ids', function () {
+    assert(~fixtures.payform.indexOf('## Browser `<input>` Helpers'))
+    $ = marky(fixtures.payform, {prefixHeadingIds: false})
+    assert.equal($('h2#browser-input-helpers a').length, 1)
+    assert.equal($('h2#browser-input-helpers a').html(), 'Browser <code>&lt;input&gt;</code> Helpers')
+  })
+
+  it('properly handles headings lacking a space between the leading #(s) and heading text', function () {
+    assert(~fixtures.lazyheading.indexOf('#lazy heading'))
+    $ = marky(fixtures.lazyheading, {prefixHeadingIds: false})
+    assert.equal($('h1#lazy-heading-1').length, 1)
+    assert.equal($('h2#lazy-heading-2').length, 1)
+    assert.equal($('h3#lazy-heading-3').length, 1)
+    assert.equal($('h4#lazy-heading-4').length, 1)
+    assert.equal($('h5#lazy-heading-5').length, 1)
+    assert.equal($('h6#lazy-heading-6').length, 1)
+  })
+})
diff --git a/test/index.js b/test/index.js
index 5b6b0c0..bf3828e 100644
--- a/test/index.js
+++ b/test/index.js
@@ -1,696 +1,12 @@
-/* globals before, describe, it */
-
-var assert = require('assert')
-var path = require('path')
-var fixtures = require('./fixtures.js')
-var marky = require('..')
-
-describe('marky-markdown', function () {
-  it('is a function', function () {
-    assert(marky)
-    assert(typeof marky === 'function')
-  })
-
-  it('accepts a markdown string and returns a cheerio DOM object', function () {
-    var $ = marky('hello, world')
-    assert($.html)
-    assert($._root)
-    assert($._options)
-    assert(~$.html().indexOf('<p>hello, world</p>\n'))
-  })
-
-  it('throws an error if first argument is not a string', function () {
-    assert.throws(
-      function () { marky(null) },
-      /first argument must be a string/
-    )
-  })
-})
-
-describe('markdown processing and syntax highlighting', function () {
-  var $
-  before(function () {
-    $ = marky(fixtures.basic, {highlightSyntax: true})
-  })
-
-  it('preserves query parameters in URLs when making them into links', function () {
-    assert(~fixtures.basic.indexOf('watch?v=dQw4w9WgXcQ'))
-    assert.equal($("a[href*='youtube.com']").attr('href'), 'https://www.youtube.com/watch?v=dQw4w9WgXcQ')
-  })
-
-  it('converts github flavored fencing to code blocks', function () {
-    assert(~fixtures.basic.indexOf('```js'))
-    assert($('code').length)
-  })
-
-  it('adds js class to javascript blocks', function () {
-    assert(~fixtures.basic.indexOf('```js'))
-    assert($('code.js').length)
-  })
-
-  it('adds sh class to shell blocks', function () {
-    assert(~fixtures.basic.indexOf('```sh'))
-    assert($('code.sh').length)
-  })
-
-  it('adds coffeescript class to coffee blocks', function () {
-    assert(~fixtures.basic.indexOf('```coffee'))
-    assert($('code.coffeescript').length)
-  })
-
-  it('adds diff class to diff blocks', function () {
-    assert(~fixtures.basic.indexOf('```diff'))
-    assert($('code.diff').length)
-  })
-
-  it('adds highlight class to all blocks', function () {
-    assert.equal($('code').length, $('code.highlight').length)
-  })
-
-  it('applies inline syntax highlighting classes to javascript', function () {
-    assert($('.js.modifier').length)
-    assert($('.js.function').length)
-  })
-
-  it('applies inline syntax highlighting classes to shell', function () {
-    assert($('.shell.builtin').length)
-  })
-
-  it('applies inline syntax highlighting classes to coffeescript', function () {
-    assert($('.coffee.begin').length)
-  })
-
-  it('applies inline syntax highlighting classes to diffs', function () {
-    assert($('.diff.inserted').length)
-    assert($('.diff.deleted').length)
-  })
-
-  it('does not encode entities within code blocks', function () {
-    assert(~fixtures.enterprise.indexOf('"name": "@myco/anypackage"'))
-    var $ = marky(fixtures.enterprise)
-    assert(!~$.html().indexOf('<span>quot</span>'))
-    assert(~$.html().indexOf('<span>&quot;</span>'))
-  })
-
-  it('linkifies fully-qualified URLs', function () {
-    assert(~fixtures['maintenance-modules'].indexOf('- https://gist.github.com/sindresorhus/8435329'))
-    var $ = marky(fixtures['maintenance-modules'])
-    assert($("a[href='https://gist.github.com/sindresorhus/8435329']").length)
-  })
-
-  it('replaces markdown syntax for emoji with unicode for the emoji', function () {
-    assert(~fixtures.github.indexOf(':sparkles:'))
-    var $ = marky(fixtures.github)
-    assert($.html().indexOf('✨'))
-  })
-
-  it('does not convert text emoticons to unicode', function () {
-    assert(~fixtures.github.indexOf(':)'))
-    var $ = marky(fixtures.github)
-    assert(~$.html().indexOf(':)'))
-  })
-})
-
-describe('sanitize', function () {
-  var $
-
-  before(function () {
-    $ = marky(fixtures.dirty)
-  })
-
-  it('removes script tags', function () {
-    assert(~fixtures.dirty.indexOf('<script'))
-    assert(!$('script').length)
-  })
-
-  it('can be disabled to allow input from trusted sources', function () {
-    assert(~fixtures.dirty.indexOf('<script'))
-    var $ = marky(fixtures.dirty, {sanitize: false})
-    assert.equal($('script').length, 1)
-    assert.equal($("script[src='http://malware.com']").length, 1)
-    assert.equal($("script[type='text/javascript']").length, 1)
-    assert.equal($("script[charset='utf-8']").length, 1)
-  })
-
-  it('allows img tags', function () {
-    assert($('img').length)
-    assert.equal($('img').attr('width'), '600')
-    assert.equal($('img').attr('height'), '400')
-    assert.equal($('img').attr('valign'), 'middle')
-    assert.equal($('img').attr('onclick'), undefined)
-  })
-
-  it('allows h1/h2/h3/h4/h5/h6 tags to preserve their dom id', function () {
-    assert($('h1').attr('id'))
-    assert($('h2').attr('id'))
-    assert(!$('h3').attr('id'))
-    assert($('h4').attr('id'))
-    assert($('h5').attr('id'))
-    assert($('h6').attr('id'))
-  })
-
-  it('removes classnames from elements', function () {
-    assert(~fixtures.dirty.indexOf('class="xxx"'))
-    assert(!$('.xxx').length)
-  })
-
-  it('allows classnames on code tags', function () {
-    assert($('code.highlight').length)
-  })
-
-  it('allows the <s> strikethrough element', function () {
-    assert(~fixtures.dirty.indexOf('~~orange~~'))
-    assert.equal($('s').text(), 'orange')
-  })
-
-  it('disallows iframes from sources other than youtube', function () {
-    var $ = marky(fixtures.basic)
-    assert(~fixtures.basic.indexOf('<iframe src="//www.youtube.com/embed/3I78ELjTzlQ'))
-    assert(~fixtures.basic.indexOf('<iframe src="//malware.com'))
-    assert.equal($('iframe').length, 2)
-    assert.equal($('iframe').eq(0).attr('src'), '//www.youtube.com/embed/3I78ELjTzlQ')
-    assert.equal($('iframe').eq(1).attr('src'), 'https://www.youtube.com/embed/DN4yLZB1vUQ')
-  })
-
-  it('allows the <ins> element', function () {
-    assert(~fixtures.dirty.indexOf('<ins>'))
-    assert.equal($('ins').text(), 'inserted')
-  })
-
-  it('allows the <del> element', function () {
-    assert(~fixtures.dirty.indexOf('<del>'))
-    assert.equal($('del').text(), 'deleted')
-  })
-
-  it('allows the <sub> element', function () {
-    assert(~fixtures.dirty.indexOf('<sub>'))
-    assert.equal($('sub').text(), 'subscript')
-  })
-
-  it('allows the <sup> element', function () {
-    assert(~fixtures.dirty.indexOf('<sup>'))
-    assert.equal($('sup').text(), 'superscript')
-  })
-})
-
-describe('badges', function () {
-  var $
-
-  before(function () {
-    $ = marky(fixtures.badges)
-  })
-
-  it('adds a badge class to img tags containing badge images', function () {
-    assert($('img').length)
-    assert.equal($('img').length, $('img.badge').length)
-  })
-
-  it('adds a badge-only class to p tags containing nothing more than a badge', function () {
-    assert.equal($('p:not(.badge-only)').length, 2)
-    assert.equal($('p.badge-only').length, $('p').length - 2)
-  })
-})
-
-describe('gravatar', function () {
-  var $
-
-  before(function () {
-    $ = marky(fixtures.gravatar)
-  })
-
-  it('replaces insecure gravatar img src URLs with secure HTTPS URLs', function () {
-    assert(~fixtures.gravatar.indexOf('http://gravatar.com/avatar/123?s=50&d=retro'))
-    assert.equal($('img').length, 3)
-    assert.equal($('img').eq(0).attr('src'), 'https://secure.gravatar.com/avatar/123?s=50&d=retro')
-  })
-
-  it('leaves secure gravatar URLs untouched', function () {
-    assert(~fixtures.gravatar.indexOf('https://secure.gravatar.com/avatar/456?s=50&d=retro'))
-    assert.equal($('img').eq(1).attr('src'), 'https://secure.gravatar.com/avatar/456?s=50&d=retro')
-  })
-
-  it('leaves non-gravtar URLs untouched', function () {
-    assert(~fixtures.gravatar.indexOf('http://not-gravatar.com/foo'))
-    assert.equal($('img').eq(2).attr('src'), 'http://not-gravatar.com/foo')
-  })
-})
-
-describe('github', function () {
-  describe('when package repo is on github', function () {
-    var $
-    var pkg = {
-      name: 'wahlberg',
-      repository: {
-        type: 'git',
-        url: 'https://github.com/mark/wahlberg'
-      }
-    }
-
-    before(function () {
-      $ = marky(fixtures.github, {package: pkg})
-    })
-
-    it('rewrites relative link hrefs to absolute', function () {
-      assert(~fixtures.github.indexOf('(relative/file.js)'))
-      assert($("a[href='https://github.com/mark/wahlberg/blob/master/relative/file.js']").length)
-    })
-
-    it('rewrites slashy relative links hrefs to absolute', function () {
-      assert(~fixtures.github.indexOf('(/slashy/poo)'))
-      assert($("a[href='https://github.com/mark/wahlberg/blob/master/slashy/poo']").length)
-    })
-
-    it('leaves protocol-relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('(//protocollie.com)'))
-      assert($("a[href='//protocollie.com']").length)
-    })
-
-    it('leaves hashy URLs alone', function () {
-      assert(~fixtures.github.indexOf('(#header)'))
-      assert($("a[href='#header']").length)
-    })
-
-    it('replaces relative img URLs with npm CDN URLs', function () {
-      assert(~fixtures.github.indexOf('![](relative.png)'))
-      assert($("img[src='https://raw.githubusercontent.com/mark/wahlberg/master/relative.png']").length)
-    })
-
-    it('replaces slashy relative img URLs with npm CDN URLs', function () {
-      assert(~fixtures.github.indexOf('![](/slashy/deep.png)'))
-      assert($("img[src='https://raw.githubusercontent.com/mark/wahlberg/master/slashy/deep.png']").length)
-    })
-
-    it('leaves protocol relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('![](//protocollie.com/woof.png)'))
-      assert($("img[src='//protocollie.com/woof.png']").length)
-    })
-
-    it('leaves HTTPS URLs alone', function () {
-      assert(~fixtures.github.indexOf('![](https://secure.com/good.png)'))
-      assert($("img[src='https://secure.com/good.png']").length)
-    })
-  })
-
-  describe('when package repo is NOT on github', function () {
-    var $
-    var pkg = {
-      name: 'bitbucketberg',
-      repository: {
-        type: 'git',
-        url: 'https://bitbucket.com/mark/bitbucketberg'
-      }
-    }
-
-    before(function () {
-      $ = marky(fixtures.github, {package: pkg})
-    })
-
-    it('leaves relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('(relative/file.js)'))
-      assert($("a[href='relative/file.js']").length)
-    })
-
-    it('leaves slashy relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('(/slashy/poo)'))
-      assert($("a[href='/slashy/poo']").length)
-    })
-
-    it('leaves protocol-relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('(//protocollie.com)'))
-      assert($("a[href='//protocollie.com']").length)
-    })
-
-    it('leaves hashy URLs alone', function () {
-      assert(~fixtures.github.indexOf('(#header)'))
-      assert($("a[href='#header']").length)
-    })
-
-    it('leaves relative img alone', function () {
-      assert(~fixtures.github.indexOf('![](relative.png)'))
-      assert($("img[src='relative.png']").length)
-    })
-
-    it('leaves slashy relative img URLs alone', function () {
-      assert(~fixtures.github.indexOf('![](/slashy/deep.png)'))
-      assert($("img[src='/slashy/deep.png']").length)
-    })
-
-    it('leaves protocol relative URLs alone', function () {
-      assert(~fixtures.github.indexOf('![](//protocollie.com/woof.png)'))
-      assert($("img[src='//protocollie.com/woof.png']").length)
-    })
-
-    it('leaves HTTPS URLs alone', function () {
-      assert(~fixtures.github.indexOf('![](https://secure.com/good.png)'))
-      assert($("img[src='https://secure.com/good.png']").length)
-    })
-  })
-})
-
-describe('youtube', function () {
-  var $
-  var iframes
-
-  before(function () {
-    $ = marky(fixtures.basic)
-    iframes = $('.youtube-video > iframe')
-  })
-
-  it('wraps iframes in a div for stylability', function () {
-    assert(!~fixtures.basic.indexOf('youtube-video'))
-    assert.equal(iframes.length, 2)
-  })
-
-  it('removes iframe width and height properties', function () {
-    var iframe = iframes.eq(0)
-    assert.equal(iframe.attr('width'), null)
-    assert.equal(iframe.attr('height'), null)
-  })
-
-  it('preserves existing src, frameborder, and allowfullscreen properties', function () {
-    var iframe = iframes.eq(0)
-    assert.equal(iframe.attr('src'), '//www.youtube.com/embed/3I78ELjTzlQ')
-    assert.equal(iframe.attr('frameborder'), '0')
-    assert.equal(iframe.attr('allowfullscreen'), '')
-  })
-
-  it('preserves full src, does not add missing frameborder and allowfullscreen attributes', function () {
-    var iframe2 = iframes.eq(1)
-    assert.equal(iframe2.attr('src'), 'https://www.youtube.com/embed/DN4yLZB1vUQ')
-    assert.equal(typeof iframe2.attr('frameborder'), 'undefined')
-    assert.equal(typeof iframe2.attr('allowfullscreen'), 'undefined')
-  })
-})
-
-describe('packagize', function () {
-  var packages = {
-    wibble: {
-      name: 'wibble',
-      description: 'A package called wibble'
-    },
-    wobble: {
-      name: 'wobble',
-      description: 'wibble'
-    },
-    dangledor: {
-      name: 'dangledor',
-      description: 'dangledor need not roar'
-    },
-    '@burble/wibble': {
-      name: '@burble/wibble',
-      description: 'A package called @burble/wibble!'
-    }
-  }
-
-  describe('name', function () {
-    it("adds .package-name-redundant class to first h1 if it's similar to package.name", function () {
-      var $ = marky(fixtures.wibble, {package: packages.wibble})
-      assert.equal($('h1.package-name-redundant').length, 1)
-    })
-
-    it("adds .package-name-redundant class to first h1 if it's similar to a scoped package.name", function () {
-      var $ = marky(fixtures.burblewibble, {package: packages['@burble/wibble']})
-      assert.equal($('h1.package-name-redundant').length, 1)
-    })
-
-    it('leaves first h1 alone if it differs from package.name', function () {
-      var $ = marky(fixtures.wibble, {package: packages.dangledor})
-      assert.equal($('h1.package-name-redundant').length, 0)
-      assert.equal($('h1:not(.package-name)').text(), 'wibble.js')
-    })
-  })
-
-  describe('description', function () {
-    it("adds .package-description-redundant class to first h1 if it's similar to package.description", function () {
-      var $ = marky(fixtures.wibble, {package: packages.wobble})
-      assert.equal($('h1.package-description-redundant').length, 1)
-    })
-
-    it('leaves first h1 alone if it differs from package.description', function () {
-      var $ = marky(fixtures.wibble, {package: packages.dangledor})
-      assert.equal($('h1.package-description-redundant').length, 0)
-      assert.equal($('h1:not(.package-name)').text(), 'wibble.js')
-    })
-
-    it("adds .package-description-redundant class to first p if it's similar to package.description", function () {
-      var $ = marky(fixtures.wibble, {package: packages.wibble})
-      assert.equal($('p.package-description-redundant').length, 1)
-    })
-
-    it('leaves first p alone if it differs from package.description', function () {
-      var $ = marky(fixtures.wibble, {package: packages.dangledor})
-      assert.equal($('p.package-description-redundant').length, 0)
-      assert.equal($('p:not(.package-description)').first().text(), 'A package called wibble!')
-    })
-  })
-
-  describe('parsePackageDescription()', function () {
-    it('is a method for parsing package descriptions', function () {
-      assert.equal(typeof marky.parsePackageDescription, 'function')
-    })
-
-    it('parses description as markdown and removes script tags', function () {
-      var description = marky.parsePackageDescription('bad <script>/xss</script> [hax](http://hax.com)')
-      assert.equal(description, 'bad  <a href="http://hax.com">hax</a>')
-    })
-
-    it('safely handles inline code blocks', function () {
-      var description = marky.parsePackageDescription('Browser `<input type="text">` Helpers')
-      assert.equal(description, 'Browser <code>&lt;input type=&quot;text&quot;&gt;</code> Helpers')
-    })
-
-    it('safely handles script tags in inline code blocks', function () {
-      var description = marky.parsePackageDescription('Here comes a `<script>` tag')
-      assert.equal(description, 'Here comes a <code>&lt;script&gt;</code> tag')
-    })
-  })
-})
-
-describe('fixtures', function () {
-  it('is a key-value object', function () {
-    assert(fixtures)
-    assert(typeof fixtures === 'object')
-    assert(!Array.isArray(fixtures))
-  })
-
-  it('contains stringified markdown files as values', function () {
-    var keys = Object.keys(fixtures)
-    assert(keys.length)
-    keys.forEach(function (key) {
-      assert(fixtures[key])
-      if (key === 'dependencies' || key === 'examples') return
-      assert(typeof fixtures[key] === 'string')
-    })
-  })
-
-  it('has a property that is an alphabetical list of dependencies', function () {
-    assert(Array.isArray(fixtures.dependencies))
-    assert(fixtures.dependencies.length)
-  })
-
-  it('has a property that is an alphabetical list of saved examples', function () {
-    assert(Array.isArray(fixtures.examples))
-    assert(fixtures.examples.length)
-  })
-
-  it('includes some real package readmes right from node_modules', function () {
-    assert(fixtures.lodash.length)
-    assert(fixtures['property-ttl'].length)
-    assert(fixtures['sanitize-html'].length)
-  })
-
-  it('includes some real package readmes in static fixtures', function () {
-    assert(fixtures.async.length)
-    assert(fixtures.express.length)
-    assert(fixtures['johnny-five'].length)
-  })
-})
-
-describe('headings', function () {
-  var $
-
-  before(function () {
-    $ = marky(fixtures.dirty)
-  })
-
-  it('injects hashy anchor tags into headings that have DOM ids', function () {
-    assert(~fixtures.dirty.indexOf('# h1'))
-    assert($("h1 a[href='#h1']").length)
-  })
-
-  it('adds deep-link class to modified headings', function () {
-    assert(~fixtures.dirty.indexOf('# h1'))
-    assert($("h1.deep-link a[href='#h1']").length)
-  })
-
-  it("doesn't inject anchor tags into headings that already contain anchors", function () {
-    assert(~fixtures.dirty.indexOf('### [h3](/already/linky)'))
-    assert($("h3 a[href='/already/linky']").length)
-  })
-
-  it('applies a prefix to generated DOM ids by default', function () {
-    assert(~fixtures.dirty.indexOf('## h2'))
-    assert.equal($('h2#user-content-h2').length, 1)
-  })
-
-  it('allows id prefixes to be disabled with prefixHeadingIds', function () {
-    assert(~fixtures.dirty.indexOf('#### This is a TEST'))
-    $ = marky(fixtures.dirty, {prefixHeadingIds: false})
-    assert.equal($('h4#this-is-a-test').length, 1)
-  })
-
-  it('allows a dash in generated DOM ids just like GitHub', function () {
-    assert(~fixtures.github.indexOf('### heading with a - dash'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#heading-with-a---dash a').length, 1)
-  })
-
-  it('allows a trailing dash in generated DOM ids just like GitHub', function () {
-    assert(~fixtures.github.indexOf('### heading with a trailing dash -'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#heading-with-a-trailing-dash-- a').length, 1)
-  })
-
-  it('allows underscores in generated DOM ids like GitHub', function () {
-    assert(~fixtures.github.indexOf('### heading with an _ underscore'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#heading-with-an-_-underscore a').length, 1)
-  })
-
-  it('filters periods in generated DOM ids like GitHub', function () {
-    assert(~fixtures.github.indexOf('### heading with a period.txt'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#heading-with-a-periodtxt').length, 1)
-  })
-
-  it('allows two spaces even after filtering like GitHub', function () {
-    assert(~fixtures.github.indexOf('### exchange.bind_headers(exchange, routing [, bindCallback])'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#exchangebind_headersexchange-routing--bindcallback').length, 1)
-  })
-
-  it('add suffix to duplicate generated DOM ids like GitHub', function () {
-    assert(~fixtures.github.indexOf('### duplicate'))
-    assert(~fixtures.github.indexOf('### duplicate('))
-    assert(~fixtures.github.indexOf('### duplicate)'))
-    $ = marky(fixtures.github)
-    assert.equal($('h3#duplicate a').length, 1)
-    assert.equal($('h3#duplicate-1 a').length, 1)
-    assert.equal($('h3#duplicate-2 a').length, 1)
-  })
-
-  it('encodes innerHTML and removes angle brackets before generating ids', function () {
-    assert(~fixtures.payform.indexOf('## Browser `<input>` Helpers'))
-    $ = marky(fixtures.payform, {prefixHeadingIds: false})
-    assert.equal($('h2#browser-input-helpers a').length, 1)
-    assert.equal($('h2#browser-input-helpers a').html(), 'Browser <code>&lt;input&gt;</code> Helpers')
-  })
-
-  it('properly handles headings lacking a space between the leading #(s) and heading text', function () {
-    assert(~fixtures.lazyheading.indexOf('#lazy heading'))
-    $ = marky(fixtures.lazyheading, {prefixHeadingIds: false})
-    assert.equal($('h1#lazy-heading-1').length, 1)
-    assert.equal($('h2#lazy-heading-2').length, 1)
-    assert.equal($('h3#lazy-heading-3').length, 1)
-    assert.equal($('h4#lazy-heading-4').length, 1)
-    assert.equal($('h5#lazy-heading-5').length, 1)
-    assert.equal($('h6#lazy-heading-6').length, 1)
-  })
-})
-
-describe('cdn', function () {
-  describe('when serveImagesWithCDN is true', function () {
-    var $
-    var options = {
-      package: {name: 'foo', version: '1.0.0'},
-      serveImagesWithCDN: true
-    }
-
-    before(function () {
-      $ = marky(fixtures.basic, options)
-    })
-
-    it('replaces relative img URLs with npm CDN URLs', function () {
-      assert(~fixtures.basic.indexOf('![](relative.png)'))
-      assert($("img[src='https://cdn.npm.im/foo@1.0.0/relative.png']").length)
-    })
-
-    it('replaces slashy relative img URLs with npm CDN URLs', function () {
-      assert(~fixtures.basic.indexOf('![](/slashy/deep.png)'))
-      assert($("img[src='https://cdn.npm.im/foo@1.0.0/slashy/deep.png']").length)
-    })
-
-    it('leaves protocol relative URLs alone', function () {
-      assert(~fixtures.basic.indexOf('![](//protocollie.com/woof.png)'))
-      assert($("img[src='//protocollie.com/woof.png']").length)
-    })
-
-    it('leaves HTTPS URLs alone', function () {
-      assert(~fixtures.basic.indexOf('![](https://secure.com/good.png)'))
-      assert($("img[src='https://secure.com/good.png']").length)
-    })
-  })
-
-  describe('when serveImagesWithCDN is false (default)', function () {
-    var $
-    var options = {
-      package: {
-        name: 'foo',
-        version: '1.0.0'
-      }
-    }
-
-    before(function () {
-      $ = marky(fixtures.basic, options)
-    })
-
-    it('leaves relative img alone', function () {
-      assert(~fixtures.basic.indexOf('![](relative.png)'))
-      assert($("img[src='relative.png']").length)
-    })
-
-    it('leaves slashy relative img URLs alone', function () {
-      assert(~fixtures.basic.indexOf('![](/slashy/deep.png)'))
-      assert($("img[src='/slashy/deep.png']").length)
-    })
-
-    it('leaves protocol relative URLs alone', function () {
-      assert(~fixtures.basic.indexOf('![](//protocollie.com/woof.png)'))
-      assert($("img[src='//protocollie.com/woof.png']").length)
-    })
-
-    it('leaves HTTPS URLs alone', function () {
-      assert(~fixtures.basic.indexOf('![](https://secure.com/good.png)'))
-      assert($("img[src='https://secure.com/good.png']").length)
-    })
-  })
-})
-
-describe('real readmes in the wild', function () {
-  function parsePackages (packages, done, getPackage) {
-    assert(Array.isArray(packages))
-    assert(packages.length)
-    packages.forEach(function (name) {
-      console.log('\t' + name)
-      assert(typeof fixtures[name] === 'string')
-      var $ = marky(fixtures[name], {package: getPackage(name)})
-      assert($.html().length > 100)
-
-      if (name === packages[packages.length - 1]) {
-        return done()
-      }
-    })
-  }
-
-  it('parses all saved fixture readmes', function (done) {
-    parsePackages(fixtures.examples, done, function (name) {
-      return {name: name}
-    })
-  })
-
-  it('parses all dependency readmes', function (done) {
-    parsePackages(fixtures.dependencies, done, function (name) {
-      return require(path.resolve('node_modules', name, 'package.json'))
-    })
-  })
-})
+// the unit test suite lives in these modules
+require('./marky')
+require('./markdown')
+require('./sanitize')
+require('./badges')
+require('./gravatar')
+require('./github')
+require('./youtube')
+require('./packagize')
+require('./headings')
+require('./cdn')
+require('./readmes')
diff --git a/test/markdown.js b/test/markdown.js
new file mode 100644
index 0000000..e80465a
--- /dev/null
+++ b/test/markdown.js
@@ -0,0 +1,89 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('markdown processing and syntax highlighting', function () {
+  var $
+  before(function () {
+    $ = marky(fixtures.basic, {highlightSyntax: true})
+  })
+
+  it('preserves query parameters in URLs when making them into links', function () {
+    assert(~fixtures.basic.indexOf('watch?v=dQw4w9WgXcQ'))
+    assert.equal($("a[href*='youtube.com']").attr('href'), 'https://www.youtube.com/watch?v=dQw4w9WgXcQ')
+  })
+
+  it('converts github flavored fencing to code blocks', function () {
+    assert(~fixtures.basic.indexOf('```js'))
+    assert($('code').length)
+  })
+
+  it('adds js class to javascript blocks', function () {
+    assert(~fixtures.basic.indexOf('```js'))
+    assert($('code.js').length)
+  })
+
+  it('adds sh class to shell blocks', function () {
+    assert(~fixtures.basic.indexOf('```sh'))
+    assert($('code.sh').length)
+  })
+
+  it('adds coffeescript class to coffee blocks', function () {
+    assert(~fixtures.basic.indexOf('```coffee'))
+    assert($('code.coffeescript').length)
+  })
+
+  it('adds diff class to diff blocks', function () {
+    assert(~fixtures.basic.indexOf('```diff'))
+    assert($('code.diff').length)
+  })
+
+  it('adds highlight class to all blocks', function () {
+    assert.equal($('code').length, $('code.highlight').length)
+  })
+
+  it('applies inline syntax highlighting classes to javascript', function () {
+    assert($('.js.modifier').length)
+    assert($('.js.function').length)
+  })
+
+  it('applies inline syntax highlighting classes to shell', function () {
+    assert($('.shell.builtin').length)
+  })
+
+  it('applies inline syntax highlighting classes to coffeescript', function () {
+    assert($('.coffee.begin').length)
+  })
+
+  it('applies inline syntax highlighting classes to diffs', function () {
+    assert($('.diff.inserted').length)
+    assert($('.diff.deleted').length)
+  })
+
+  it('does not encode entities within code blocks', function () {
+    assert(~fixtures.enterprise.indexOf('"name": "@myco/anypackage"'))
+    var $ = marky(fixtures.enterprise)
+    assert(!~$.html().indexOf('<span>quot</span>'))
+    assert(~$.html().indexOf('<span>&quot;</span>'))
+  })
+
+  it('linkifies fully-qualified URLs', function () {
+    assert(~fixtures['maintenance-modules'].indexOf('- https://gist.github.com/sindresorhus/8435329'))
+    var $ = marky(fixtures['maintenance-modules'])
+    assert($("a[href='https://gist.github.com/sindresorhus/8435329']").length)
+  })
+
+  it('replaces markdown syntax for emoji with unicode for the emoji', function () {
+    assert(~fixtures.github.indexOf(':sparkles:'))
+    var $ = marky(fixtures.github)
+    assert($.html().indexOf('✨'))
+  })
+
+  it('does not convert text emoticons to unicode', function () {
+    assert(~fixtures.github.indexOf(':)'))
+    var $ = marky(fixtures.github)
+    assert(~$.html().indexOf(':)'))
+  })
+})
diff --git a/test/marky.js b/test/marky.js
new file mode 100644
index 0000000..e841ec9
--- /dev/null
+++ b/test/marky.js
@@ -0,0 +1,67 @@
+/* globals describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('marky-markdown', function () {
+  it('is a function', function () {
+    assert(marky)
+    assert(typeof marky === 'function')
+  })
+
+  it('accepts a markdown string and returns a cheerio DOM object', function () {
+    var $ = marky('hello, world')
+    assert($.html)
+    assert($._root)
+    assert($._options)
+    assert(~$.html().indexOf('<p>hello, world</p>\n'))
+  })
+
+  it('throws an error if first argument is not a string', function () {
+    assert.throws(
+      function () { marky(null) },
+      /first argument must be a string/
+    )
+  })
+})
+
+describe('fixtures', function () {
+  it('is a key-value object', function () {
+    assert(fixtures)
+    assert(typeof fixtures === 'object')
+    assert(!Array.isArray(fixtures))
+  })
+
+  it('contains stringified markdown files as values', function () {
+    var keys = Object.keys(fixtures)
+    assert(keys.length)
+    keys.forEach(function (key) {
+      assert(fixtures[key])
+      if (key === 'dependencies' || key === 'examples') return
+      assert(typeof fixtures[key] === 'string')
+    })
+  })
+
+  it('has a property that is an alphabetical list of dependencies', function () {
+    assert(Array.isArray(fixtures.dependencies))
+    assert(fixtures.dependencies.length)
+  })
+
+  it('has a property that is an alphabetical list of saved examples', function () {
+    assert(Array.isArray(fixtures.examples))
+    assert(fixtures.examples.length)
+  })
+
+  it('includes some real package readmes right from node_modules', function () {
+    assert(fixtures.lodash.length)
+    assert(fixtures['property-ttl'].length)
+    assert(fixtures['sanitize-html'].length)
+  })
+
+  it('includes some real package readmes in static fixtures', function () {
+    assert(fixtures.async.length)
+    assert(fixtures.express.length)
+    assert(fixtures['johnny-five'].length)
+  })
+})
diff --git a/test/packagize.js b/test/packagize.js
new file mode 100644
index 0000000..30a6c0a
--- /dev/null
+++ b/test/packagize.js
@@ -0,0 +1,89 @@
+/* globals describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('packagize', function () {
+  var packages = {
+    wibble: {
+      name: 'wibble',
+      description: 'A package called wibble'
+    },
+    wobble: {
+      name: 'wobble',
+      description: 'wibble'
+    },
+    dangledor: {
+      name: 'dangledor',
+      description: 'dangledor need not roar'
+    },
+    '@burble/wibble': {
+      name: '@burble/wibble',
+      description: 'A package called @burble/wibble!'
+    }
+  }
+
+  describe('name', function () {
+    it("adds .package-name-redundant class to first h1 if it's similar to package.name", function () {
+      var $ = marky(fixtures.wibble, {package: packages.wibble})
+      assert.equal($('h1.package-name-redundant').length, 1)
+    })
+
+    it("adds .package-name-redundant class to first h1 if it's similar to a scoped package.name", function () {
+      var $ = marky(fixtures.burblewibble, {package: packages['@burble/wibble']})
+      assert.equal($('h1.package-name-redundant').length, 1)
+    })
+
+    it('leaves first h1 alone if it differs from package.name', function () {
+      var $ = marky(fixtures.wibble, {package: packages.dangledor})
+      assert.equal($('h1.package-name-redundant').length, 0)
+      assert.equal($('h1:not(.package-name)').text(), 'wibble.js')
+    })
+  })
+
+  describe('description', function () {
+    it("adds .package-description-redundant class to first h1 if it's similar to package.description", function () {
+      var $ = marky(fixtures.wibble, {package: packages.wobble})
+      assert.equal($('h1.package-description-redundant').length, 1)
+    })
+
+    it('leaves first h1 alone if it differs from package.description', function () {
+      var $ = marky(fixtures.wibble, {package: packages.dangledor})
+      assert.equal($('h1.package-description-redundant').length, 0)
+      assert.equal($('h1:not(.package-name)').text(), 'wibble.js')
+    })
+
+    it("adds .package-description-redundant class to first p if it's similar to package.description", function () {
+      var $ = marky(fixtures.wibble, {package: packages.wibble})
+      assert.equal($('p.package-description-redundant').length, 1)
+    })
+
+    it('leaves first p alone if it differs from package.description', function () {
+      var $ = marky(fixtures.wibble, {package: packages.dangledor})
+      assert.equal($('p.package-description-redundant').length, 0)
+      assert.equal($('p:not(.package-description)').first().text(), 'A package called wibble!')
+    })
+  })
+
+  describe('parsePackageDescription()', function () {
+    it('is a method for parsing package descriptions', function () {
+      assert.equal(typeof marky.parsePackageDescription, 'function')
+    })
+
+    it('parses description as markdown and removes script tags', function () {
+      var description = marky.parsePackageDescription('bad <script>/xss</script> [hax](http://hax.com)')
+      assert.equal(description, 'bad  <a href="http://hax.com">hax</a>')
+    })
+
+    it('safely handles inline code blocks', function () {
+      var description = marky.parsePackageDescription('Browser `<input type="text">` Helpers')
+      assert.equal(description, 'Browser <code>&lt;input type=&quot;text&quot;&gt;</code> Helpers')
+    })
+
+    it('safely handles script tags in inline code blocks', function () {
+      var description = marky.parsePackageDescription('Here comes a `<script>` tag')
+      assert.equal(description, 'Here comes a <code>&lt;script&gt;</code> tag')
+    })
+  })
+})
diff --git a/test/readmes.js b/test/readmes.js
new file mode 100644
index 0000000..6ed318d
--- /dev/null
+++ b/test/readmes.js
@@ -0,0 +1,35 @@
+/* globals describe, it */
+
+var assert = require('assert')
+var path = require('path')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('real readmes in the wild', function () {
+  function parsePackages (packages, done, getPackage) {
+    assert(Array.isArray(packages))
+    assert(packages.length)
+    packages.forEach(function (name) {
+      console.log('\t' + name)
+      assert(typeof fixtures[name] === 'string')
+      var $ = marky(fixtures[name], {package: getPackage(name)})
+      assert($.html().length > 100)
+
+      if (name === packages[packages.length - 1]) {
+        return done()
+      }
+    })
+  }
+
+  it('parses all saved fixture readmes', function (done) {
+    parsePackages(fixtures.examples, done, function (name) {
+      return {name: name}
+    })
+  })
+
+  it('parses all dependency readmes', function (done) {
+    parsePackages(fixtures.dependencies, done, function (name) {
+      return require(path.resolve('node_modules', name, 'package.json'))
+    })
+  })
+})
diff --git a/test/repo-github.js b/test/repo-github.js
new file mode 100644
index 0000000..935070b
--- /dev/null
+++ b/test/repo-github.js
@@ -0,0 +1,60 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('when package repo is on github', function () {
+  var $
+  var pkg = {
+    name: 'wahlberg',
+    repository: {
+      type: 'git',
+      url: 'https://github.com/mark/wahlberg'
+    }
+  }
+
+  before(function () {
+    $ = marky(fixtures.github, {package: pkg})
+  })
+
+  it('rewrites relative link hrefs to absolute', function () {
+    assert(~fixtures.github.indexOf('(relative/file.js)'))
+    assert($("a[href='https://github.com/mark/wahlberg/blob/master/relative/file.js']").length)
+  })
+
+  it('rewrites slashy relative links hrefs to absolute', function () {
+    assert(~fixtures.github.indexOf('(/slashy/poo)'))
+    assert($("a[href='https://github.com/mark/wahlberg/blob/master/slashy/poo']").length)
+  })
+
+  it('leaves protocol-relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('(//protocollie.com)'))
+    assert($("a[href='//protocollie.com']").length)
+  })
+
+  it('leaves hashy URLs alone', function () {
+    assert(~fixtures.github.indexOf('(#header)'))
+    assert($("a[href='#header']").length)
+  })
+
+  it('replaces relative img URLs with npm CDN URLs', function () {
+    assert(~fixtures.github.indexOf('![](relative.png)'))
+    assert($("img[src='https://raw.githubusercontent.com/mark/wahlberg/master/relative.png']").length)
+  })
+
+  it('replaces slashy relative img URLs with npm CDN URLs', function () {
+    assert(~fixtures.github.indexOf('![](/slashy/deep.png)'))
+    assert($("img[src='https://raw.githubusercontent.com/mark/wahlberg/master/slashy/deep.png']").length)
+  })
+
+  it('leaves protocol relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('![](//protocollie.com/woof.png)'))
+    assert($("img[src='//protocollie.com/woof.png']").length)
+  })
+
+  it('leaves HTTPS URLs alone', function () {
+    assert(~fixtures.github.indexOf('![](https://secure.com/good.png)'))
+    assert($("img[src='https://secure.com/good.png']").length)
+  })
+})
diff --git a/test/repo-other.js b/test/repo-other.js
new file mode 100644
index 0000000..af9789a
--- /dev/null
+++ b/test/repo-other.js
@@ -0,0 +1,60 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('when package repo is NOT on github', function () {
+  var $
+  var pkg = {
+    name: 'bitbucketberg',
+    repository: {
+      type: 'git',
+      url: 'https://bitbucket.com/mark/bitbucketberg'
+    }
+  }
+
+  before(function () {
+    $ = marky(fixtures.github, {package: pkg})
+  })
+
+  it('leaves relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('(relative/file.js)'))
+    assert($("a[href='relative/file.js']").length)
+  })
+
+  it('leaves slashy relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('(/slashy/poo)'))
+    assert($("a[href='/slashy/poo']").length)
+  })
+
+  it('leaves protocol-relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('(//protocollie.com)'))
+    assert($("a[href='//protocollie.com']").length)
+  })
+
+  it('leaves hashy URLs alone', function () {
+    assert(~fixtures.github.indexOf('(#header)'))
+    assert($("a[href='#header']").length)
+  })
+
+  it('leaves relative img alone', function () {
+    assert(~fixtures.github.indexOf('![](relative.png)'))
+    assert($("img[src='relative.png']").length)
+  })
+
+  it('leaves slashy relative img URLs alone', function () {
+    assert(~fixtures.github.indexOf('![](/slashy/deep.png)'))
+    assert($("img[src='/slashy/deep.png']").length)
+  })
+
+  it('leaves protocol relative URLs alone', function () {
+    assert(~fixtures.github.indexOf('![](//protocollie.com/woof.png)'))
+    assert($("img[src='//protocollie.com/woof.png']").length)
+  })
+
+  it('leaves HTTPS URLs alone', function () {
+    assert(~fixtures.github.indexOf('![](https://secure.com/good.png)'))
+    assert($("img[src='https://secure.com/good.png']").length)
+  })
+})
diff --git a/test/sanitize.js b/test/sanitize.js
new file mode 100644
index 0000000..73e5b33
--- /dev/null
+++ b/test/sanitize.js
@@ -0,0 +1,87 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('sanitize', function () {
+  var $
+
+  before(function () {
+    $ = marky(fixtures.dirty)
+  })
+
+  it('removes script tags', function () {
+    assert(~fixtures.dirty.indexOf('<script'))
+    assert(!$('script').length)
+  })
+
+  it('can be disabled to allow input from trusted sources', function () {
+    assert(~fixtures.dirty.indexOf('<script'))
+    var $ = marky(fixtures.dirty, {sanitize: false})
+    assert.equal($('script').length, 1)
+    assert.equal($("script[src='http://malware.com']").length, 1)
+    assert.equal($("script[type='text/javascript']").length, 1)
+    assert.equal($("script[charset='utf-8']").length, 1)
+  })
+
+  it('allows img tags', function () {
+    assert($('img').length)
+    assert.equal($('img').attr('width'), '600')
+    assert.equal($('img').attr('height'), '400')
+    assert.equal($('img').attr('valign'), 'middle')
+    assert.equal($('img').attr('onclick'), undefined)
+  })
+
+  it('allows h1/h2/h3/h4/h5/h6 tags to preserve their dom id', function () {
+    assert($('h1').attr('id'))
+    assert($('h2').attr('id'))
+    assert(!$('h3').attr('id'))
+    assert($('h4').attr('id'))
+    assert($('h5').attr('id'))
+    assert($('h6').attr('id'))
+  })
+
+  it('removes classnames from elements', function () {
+    assert(~fixtures.dirty.indexOf('class="xxx"'))
+    assert(!$('.xxx').length)
+  })
+
+  it('allows classnames on code tags', function () {
+    assert($('code.highlight').length)
+  })
+
+  it('allows the <s> strikethrough element', function () {
+    assert(~fixtures.dirty.indexOf('~~orange~~'))
+    assert.equal($('s').text(), 'orange')
+  })
+
+  it('disallows iframes from sources other than youtube', function () {
+    var $ = marky(fixtures.basic)
+    assert(~fixtures.basic.indexOf('<iframe src="//www.youtube.com/embed/3I78ELjTzlQ'))
+    assert(~fixtures.basic.indexOf('<iframe src="//malware.com'))
+    assert.equal($('iframe').length, 2)
+    assert.equal($('iframe').eq(0).attr('src'), '//www.youtube.com/embed/3I78ELjTzlQ')
+    assert.equal($('iframe').eq(1).attr('src'), 'https://www.youtube.com/embed/DN4yLZB1vUQ')
+  })
+
+  it('allows the <ins> element', function () {
+    assert(~fixtures.dirty.indexOf('<ins>'))
+    assert.equal($('ins').text(), 'inserted')
+  })
+
+  it('allows the <del> element', function () {
+    assert(~fixtures.dirty.indexOf('<del>'))
+    assert.equal($('del').text(), 'deleted')
+  })
+
+  it('allows the <sub> element', function () {
+    assert(~fixtures.dirty.indexOf('<sub>'))
+    assert.equal($('sub').text(), 'subscript')
+  })
+
+  it('allows the <sup> element', function () {
+    assert(~fixtures.dirty.indexOf('<sup>'))
+    assert.equal($('sup').text(), 'superscript')
+  })
+})
diff --git a/test/youtube.js b/test/youtube.js
new file mode 100644
index 0000000..2c85e7f
--- /dev/null
+++ b/test/youtube.js
@@ -0,0 +1,40 @@
+/* globals before, describe, it */
+
+var assert = require('assert')
+var marky = require('..')
+var fixtures = require('./fixtures')
+
+describe('youtube', function () {
+  var $
+  var iframes
+
+  before(function () {
+    $ = marky(fixtures.basic)
+    iframes = $('.youtube-video > iframe')
+  })
+
+  it('wraps iframes in a div for stylability', function () {
+    assert(!~fixtures.basic.indexOf('youtube-video'))
+    assert.equal(iframes.length, 2)
+  })
+
+  it('removes iframe width and height properties', function () {
+    var iframe = iframes.eq(0)
+    assert.equal(iframe.attr('width'), null)
+    assert.equal(iframe.attr('height'), null)
+  })
+
+  it('preserves existing src, frameborder, and allowfullscreen properties', function () {
+    var iframe = iframes.eq(0)
+    assert.equal(iframe.attr('src'), '//www.youtube.com/embed/3I78ELjTzlQ')
+    assert.equal(iframe.attr('frameborder'), '0')
+    assert.equal(iframe.attr('allowfullscreen'), '')
+  })
+
+  it('preserves full src, does not add missing frameborder and allowfullscreen attributes', function () {
+    var iframe2 = iframes.eq(1)
+    assert.equal(iframe2.attr('src'), 'https://www.youtube.com/embed/DN4yLZB1vUQ')
+    assert.equal(typeof iframe2.attr('frameborder'), 'undefined')
+    assert.equal(typeof iframe2.attr('allowfullscreen'), 'undefined')
+  })
+})