diff --git a/renderers/markdown.moon b/renderers/markdown.moon
index b67c5d6..765ed9e 100644
--- a/renderers/markdown.moon
+++ b/renderers/markdown.moon
@@ -10,6 +10,15 @@ _prepare_command = (cmd, ...) ->
   args = table.concat args, " "
   "#{cmd} #{args}"
 
+write_exec = (cmd, content) ->
+  fname = os.tmpname!
+  f = assert io.popen _prepare_command(cmd, fname), "w"
+
+  with f\write content
+    f\close!
+
+  fname
+
 -- config command like this in site.moon:
 -- require("renderers.markdown").cmd = "pandoc --mathjax >"
 class PandocRenderer extends require "sitegen.renderers.markdown"
@@ -17,25 +26,7 @@ class PandocRenderer extends require "sitegen.renderers.markdown"
   escape_cosmo = @escape_cosmo
 
   cmd: "pandoc --mathjax --lua-filter pygments.lua >"
-
-  pandoc: (md_source) =>
-    fname = os.tmpname!
-    with io.popen _prepare_command(@@cmd, fname), "w"
-      \write md_source
-      \close!
-
-    p = io.open fname
-    out = p\read"*a"
-
-    -- if mat = out\match('<div class="highlight"><pre>(.-)\n?</pre></div>')
-    --   rep = '<div class="sourceCode"><pre class="sourceCode ' .. 'moonscript"><code class="sourceCode ' .. 'moonscript">' .. mat .. '</code></pre></div>'
-    --   out = out\gsub('<div class="highlight"><pre>(.-)\n?</pre></div>', rep)
-
-    out
-
-    -- get rid of the div and pre inserted by pygments
-    -- assert out\match('^<div class="highlight"><pre>(.-)\n?</pre></div>'),
-      -- "Failed to parse pygmentize result, is pygments installed?"
+  pandoc: (content) => Path.read_file write_exec @@cmd, content
 
   render: (page, md_source) =>
     md_source = page\pipe "renderer.markdown.pre_render", md_source
diff --git a/spec/factory.moon b/spec/factory.moon
new file mode 100644
index 0000000..3e9adda
--- /dev/null
+++ b/spec/factory.moon
@@ -0,0 +1,43 @@
+original_Site = require "sitegen.site"
+page = require "sitegen.page"
+site_file = require "sitegen.site_file"
+
+local *
+
+next_counter = do
+  counters = setmetatable {}, __index: => 1
+  (name) ->
+    with counters[name]
+      counters[name] += 1
+
+original_Site.default_plugins = for v in *original_Site.default_plugins
+  if v\find "pygments" then continue else v
+
+Site = (opts={}) ->
+  opts.rel_path or= "."
+
+  original_Site site_file.SiteFile {
+    rel_path: opts.rel_path
+  }
+
+Page = (opts={}) ->
+  opts.site or= Site!
+
+  base = "some_page_#{next_counter "page"}"
+
+  opts.meta or= {}
+  opts.source or= "#{base}.md"
+  opts.target or= "www/#{base}.html"
+  opts.render_fn or= ->
+
+  opts.read = -> error "read disabled"
+  opts.write = -> error "write disabled"
+
+  setmetatable opts, page.Page.__base
+
+  opts.site.pages or= {}
+  table.insert opts.site.pages, opts
+
+  opts
+
+{ :Site, :Page }
diff --git a/spec/renderers_spec.moon b/spec/renderers_spec.moon
new file mode 100644
index 0000000..f1b091f
--- /dev/null
+++ b/spec/renderers_spec.moon
@@ -0,0 +1,71 @@
+factory = require "spec.factory"
+
+import trim from require "sitegen.common"
+
+flatten_html = (html) ->
+  trim (html\gsub "%>%s+%<", "><")
+
+describe "renderers", ->
+  render_for_site = (site, renderer, str, meta={}, page) ->
+    page or= factory.Page(:site)
+    page.render_fn, page.meta = renderer\load str
+    page.meta.template = false
+    for k,v in pairs meta
+      page.meta[k] = v
+    page\render!
+
+  describe "renderers.markdown", ->
+    local site, renderer
+
+    render = (...) -> render_for_site site, renderer, ...
+
+    before_each ->
+      MarkdownRenderer = require "renderers.markdown"
+      site = factory.Site!
+      renderer = MarkdownRenderer site
+
+    it "syntax highlights some code", ->
+      out = flatten_html render [[
+```lua
+print("hello world")
+```]]
+
+      assert.same [[<div class="highlight"><pre><span></span><code><span class="py-nb">print</span><span class="py-p">(</span><span class="py-s2">&quot;hello world&quot;</span><span class="py-p">)</span></code></pre></div>]], out
+
+    it "doesnt highlight code inside of a cosmo template", ->
+      site.user_vars.hello = (_, args) ->
+        { template } = args
+        template
+
+      out = flatten_html render [=[
+  ```lua
+  print 5
+  ```
+  $hello{[[
+    ```lua
+    print thing
+    ```
+  ]]}]=]
+
+      assert.same [=[<div class="highlight"><pre><span></span><code><span class="py-nb">print</span><span class="py-mi">5</span></code></pre></div><p>
+    ```lua
+    print thing
+    ```
+  </p>]=], out
+
+    it "doesn't highlight unrecognized code languages", ->
+      out = flatten_html render [[
+  ```snickerdoodle
+  this code block has an unknown label
+  ```]]
+
+      assert.same [[<div class="sourceCode"><pre class="sourceCode"><code>this code block has an unknown label</code></pre></div>]], out
+
+    it "defaults to pandoc highlighting when pygments fails to recognize code language", ->
+      out = flatten_html render [[
+```heex
+<.greet name="Jane" />
+```]]
+
+      assert.same [[<div class="sourceCode" id="cb1"><pre
+class="sourceCode heex"><code class="sourceCode elixir"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="op">&lt;.</span>greet name<span class="op">=</span><span class="st">&quot;Jane&quot;</span><span class="op">/&gt;</span></span></code></pre></div>]], out