Form renderer in a separate testable method

lib/modules/markdown.js

@@ -6,6 +6,12 @@ var marked = require('gulp-marked'),
 module.exports = {
 
   getStream: function(filePath) {
+    var renderer = this.getRenderer();
+    return vfs.src(filePath)
+      .pipe(marked({renderer: renderer}))
+  },
+
+  getRenderer: function() {
     var renderer = {};
     // Define custom renderers for markup blocks
     renderer.heading = function(text, level) {
@@ -68,8 +74,7 @@ module.exports = {
         + (escaped ? code : htmlEscape(code, true))
         + '\n</code></pre>\n';
     }
-    return vfs.src(filePath)
-      .pipe(marked({renderer: renderer}))
+    return renderer;
   }
 
 }

test/markdown.js

@@ -6,6 +6,16 @@ var gulp = require('gulp'),
 
 describe('Markdown', function() {
 
+  it('getRenderer if formed correctly', function() {
+    var renderer = markdown.getRenderer();
+    console.log(renderer);
+    expect(renderer).to.be.an('object');
+    expect(renderer.heading).to.be.an('function');
+    expect(renderer.paragraph).to.be.an('function');
+    expect(renderer.link).to.be.an('function');
+    expect(renderer.code).to.be.an('function');
+  });
+
   it('getStream returns an object', function() {
     var overview = markdown.getStream('./data/overview.md');
     expect(overview).to.be.an('object');