Return default value to toSlug func

lib/utils.js

@@ -75,15 +75,18 @@ export function toFilePath(slug) {
 
 
 export function toSlug(filePath) {
-    // Convert File Path to unique slug
 
-    // let result = filePath.replace('/','__').replace(' ','-').replace('.md', '')
+    if (Node.isFile(filePath)) {
+        return filePath.replace(postsDirectory, '')
+            .replaceAll('/','__')
+            .replaceAll(' ','--')
+            .replaceAll('&','ambersand')
+            .replace('.md', '')
+    } else {
+        //TODO handle this properly
+        return '/'
+    }
 
-    return filePath.replace(postsDirectory, '')
-        .replaceAll('/','__')
-        .replaceAll(' ','--')
-        .replaceAll('&','ambersand')
-        .replace('.md', '')
 }