Normalize .md links to .html when rendering pages

lib/parse/page.js

@@ -1,6 +1,8 @@
 var _ = require('lodash');
 var marked = require('marked');
 
+var renderer = require('./renderer');
+
 
 // Split a page up into sections (lesson, exercises, ...)
 function splitSections(nodes) {
@@ -49,10 +51,15 @@ function parsePage(src) {
         // marked's Render expects this, we don't use it yet
         section.links = {};
 
+        // Build options using defaults and our custom renderer
+        var options = _.extend({}, marked.defaults, {
+            renderer: renderer()
+        });
+
         // Render normal pages
         return {
             type: section.type,
-            content: marked.parser(section)
+            content: marked.parser(section, options)
         };
     })
     .value();

lib/parse/renderer.js

@@ -0,0 +1,27 @@
+var inherits = require('util').inherits;
+
+var marked = require('marked');
+
+
+function GitBookRenderer(options) {
+    if(!(this instanceof GitBookRenderer)) {
+        return new GitBookRenderer(options);
+    }
+    GitBookRenderer.super_.call(this, options);
+}
+inherits(GitBookRenderer, marked.Renderer);
+
+
+GitBookRenderer.prototype.link = function(href, title, text) {
+    // Replace .md extensions by .html
+    return GitBookRenderer.super_.prototype.link.call(
+        this,
+        href.replace(/\.md$/, '.html'),
+        title,
+        text
+    );
+};
+
+
+// Exports
+module.exports = GitBookRenderer;