Allow loading markdown plugins from node_modules

Author: rstacruz

lib/index.js

@@ -193,12 +193,7 @@ function renderMarkdown (files, ms, done) {
   // render each page
   each(pages, (page, fname) => {
     const file = files[page.source]
-    const html = markdownIt({
-      langPrefix: 'lang-',
-      highlight: syntaxHighlight,
-      linkify: true,
-      html: true
-    }).render(file.contents.toString())
+    const html = md(ms.metadata().markdown).render(file.contents.toString())
     const $ = cheerio.load(html)
 
     fixHtml($, fname, sources, files, page)
@@ -271,3 +266,40 @@ function inferTitle (contents) {
     if (token.type === 'heading') return stripMarkdown(token.text)
   }
 }
+
+/**
+ * Private: Returns a markdownIt instance with plugins loaded.
+ */
+
+var mdCache = {}
+
+function md (plugins) {
+  const key = JSON.stringify(plugins || {})
+  if (mdCache[key]) return mdCache[key]
+
+  var md = markdownIt({
+    langPrefix: 'lang-',
+    highlight: syntaxHighlight,
+    linkify: true,
+    html: true
+  })
+
+  if (plugins) {
+    Object.keys(plugins).forEach((plugin) => {
+      const options = plugins[plugin]
+      let pluginPath =
+        tryRequire(`markdown-it-${plugin}`) ||
+        tryRequire(`${process.cwd()}/node_modules/markdown-it-${plugin}`)
+      if (!pluginPath) throw new Error(`Can't find module 'markdown-it-${plugin}'`)
+      md = md.use(require(pluginPath), options)
+    })
+  }
+
+  mdCache[key] = md
+  return md
+}
+
+function tryRequire (name) {
+  try { return require.resolve(name) } catch (e) {}
+}
+

package.json

@@ -20,6 +20,7 @@
   "devDependencies": {
     "expect": "1.12.0",
     "istanbul": "0.3.21",
+    "markdown-it-decorate": "0.2.0",
     "mocha": "2.3.3",
     "mocha-clean": "0.4.0",
     "mocha-standard": "1.0.0",