From 50d966e6762bfd1e26762575c21906c7da503f93 Mon Sep 17 00:00:00 2001
From: alex-ju <alex-ju@users.noreply.github.com>
Date: Fri, 5 Jan 2018 11:10:31 +0000
Subject: [PATCH] Refactor navigation.js

---
 lib/file-helper.js | 21 +++++++++++++++++++++
 lib/navigation.js  | 31 +++++++++++++++++--------------
 2 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/lib/file-helper.js b/lib/file-helper.js
index 68107fe7f3..bae61b83a6 100644
--- a/lib/file-helper.js
+++ b/lib/file-helper.js
@@ -1,6 +1,7 @@
 'use strict'
 
 const fs = require('fs')
+const path = require('path')
 const nunjucks = require('nunjucks')
 
 // This helper function takes a path of a file and
@@ -52,3 +53,23 @@ exports.getHTMLCode = path => {
 
   return html
 }
+
+// This helper function takes a path and
+// returns the directories found under that path
+exports.getDirectories = itemPath => {
+  let files
+  let directories
+  try {
+    files = fs.readdirSync(itemPath)
+  } catch (err) {
+    if (err.code === 'ENOENT') {
+      console.log(err.message)
+    } else {
+      throw err
+    }
+  }
+  if (files) {
+    directories = files.filter(filePath => fs.statSync(path.join(itemPath, filePath)).isDirectory())
+  }
+  return directories
+}
diff --git a/lib/navigation.js b/lib/navigation.js
index 275374ec08..dc39e152b6 100644
--- a/lib/navigation.js
+++ b/lib/navigation.js
@@ -5,21 +5,21 @@
 // metalsmith: object containing global information such as meta data
 // done: function which must be called when the plugin has finished working
 
-const fs = require('fs')
-const path = require('path')
 const paths = require('../config/paths.json')
 const navigation = require('../config/navigation.json')
 
+const fileHelper = require('../lib/file-helper.js')
+
 module.exports = function () {
   return function (files, metalsmith, done) {
     // iterate main navigation item defined in navigation.json
     for (let item in navigation) {
-      // if is not homepage look for subitems
-      if (navigation[item].url !== '') {
+      // if we have a navigation url and it is not homepage then look for subitems
+      if (navigation[item].url && navigation[item].url !== '') {
         // define source path
         let itemPath = paths.source + navigation[item].url
         // get directories under main navigation item (e.g. ['breadcrumbs', 'checkboxes', ...])
-        let directories = fs.readdirSync(itemPath).filter(filePath => fs.statSync(path.join(itemPath, filePath)).isDirectory())
+        let directories = fileHelper.getDirectories(itemPath)
         // if we have directories convert them into menu items
         if (directories) {
           // initialise child navigation items as array
@@ -28,16 +28,19 @@ module.exports = function () {
           for (let dir in directories) {
             let url = navigation[item].url + '/' + directories[dir]
             let frontmatter = files[url + '/index.html']
-            let subitem = {
-              'url': url,
-              'label': frontmatter.title
-            }
-            // if frontmatter contains `theme` data, attach it to navigation item for grouping
-            if (frontmatter.theme) {
-              subitem.theme = frontmatter.theme
+            // if we have frontmatter for that file, create subitem
+            if (frontmatter) {
+              let subitem = {
+                'url': url,
+                'label': frontmatter.title
+              }
+              // if frontmatter contains `theme` data, attach it to navigation item for grouping
+              if (frontmatter.theme) {
+                subitem.theme = frontmatter.theme
+              }
+              // add subitem to navigation
+              navigation[item].items.push(subitem)
             }
-            // add subitem to navigation
-            navigation[item].items.push(subitem)
           }
         }
       }