Choose another slug is green

src/middleware/sluggifyMiddleware.js

@@ -1,11 +1,22 @@
+import uniqueSlug from './slugify/uniqueSlug'
 import slug from 'slug'
 
+const isUniqueFor = (context, type) => {
+  return async (slug) => {
+    const session = context.driver.session()
+    const response = await session.run(
+      `MATCH(p:${type} {slug: $slug }) return p.slug`, {
+        slug
+      })
+    session.close()
+    return response.records.length === 0
+  }
+}
+
 export default {
   Mutation: {
     CreatePost: async (resolve, root, args, context, info) => {
-      args.slug = slug(args.title, {
-        lower: true
-      })
+      args.slug = await uniqueSlug(args.title, isUniqueFor(context, 'Post'))
       const result = await resolve(root, args, context, info)
       return result
     },

src/middleware/slugify/uniqueSlug.js

@@ -1,15 +1,15 @@
 import slugify from 'slug'
-export default function uniqueSlug (string, isUnique) {
+export default async function uniqueSlug (string, isUnique) {
   let slug = slugify(string, {
     lower: true
   })
-  if (isUnique(slug)) return slug
+  if (await isUnique(slug)) return slug
 
   let count = 0
   let uniqueSlug
   do {
     count += 1
     uniqueSlug = `${slug}-${count}`
-  } while (!isUnique(uniqueSlug))
+  } while (!await isUnique(uniqueSlug))
   return uniqueSlug
 }