Validate comments length, presence/test

- Co-authored-by: Wolfgang Huss <wolle.huss@pjannto.com>
- Co-authored-by: Mike Aono <aonomike@gmail.com>

backend/src/resolvers/comments.js

@@ -1,5 +1,7 @@
 import { neo4jgraphql } from 'neo4j-graphql-js'
+import { UserInputError } from 'apollo-server'
 
+const COMMENT_MIN_LENGTH = 3
 export default {
   Query: {
     CommentByPost: async (object, params, context, resolveInfo) => {
@@ -23,6 +25,11 @@ export default {
   },
   Mutation: {
     CreateComment: async (object, params, context, resolveInfo) => {
+      const content = params.content.replace(/<(?:.|\n)*?>/gm, '').trim()
+
+      if (!params.content || content.length < COMMENT_MIN_LENGTH) {
+        throw new UserInputError(`Comment must be at least ${COMMENT_MIN_LENGTH} characters long!`)
+      }
       const { postId } = params
       delete params.postId
       const comment = await neo4jgraphql(object, params, context, resolveInfo, false)

backend/src/resolvers/comments.spec.js

@@ -44,7 +44,7 @@ describe('CreateComment', () => {
       client = new GraphQLClient(host, { headers })
     })
 
-    it('creates a post', async () => {
+    it('creates a comment', async () => {
       variables = {
         postId: 'p1',
         content: 'I\'m authorised to comment'
@@ -57,5 +57,25 @@ describe('CreateComment', () => {
 
       await expect(client.request(mutation, variables)).resolves.toMatchObject(expected)
     })
+
+    it('throw an error if an empty string is sent as content', async () => {
+      variables = {
+        postId: 'p1',
+        content: '<p></p>'
+      }
+
+      await expect(client.request(mutation, variables))
+        .rejects.toThrow('Comment must be at least 3 characters long!')
+    })
+
+    it('throws an error if a comment is less than 3 characters', async () => {
+      variables = {
+        postId: 'p1',
+        content: '<p>ab</p>'
+      }
+
+      await expect(client.request(mutation, variables))
+        .rejects.toThrow('Comment must be at least 3 characters long!')
+    })
   })
 })