Fix post language detection

- In case no language is detected set default.

backend/src/middleware/languages/languages.spec.ts

@@ -131,4 +131,25 @@ describe('languagesMiddleware', () => {
       },
     })
   })
+
+  describe('detects no language', () => {
+    it('has default language', async () => {
+      variables = {
+        ...variables,
+        content: '',
+      }
+      await expect(
+        mutate({
+          mutation: createPostMutation,
+          variables,
+        }),
+      ).resolves.toMatchObject({
+        data: {
+          CreatePost: {
+            language: 'en',
+          },
+        },
+      })
+    })
+  })
 })

backend/src/middleware/languages/languages.ts

@@ -1,20 +1,24 @@
 import LanguageDetect from 'languagedetect'
 import { removeHtmlTags } from '../helpers/cleanHtml'
 
-const setPostLanguage = (text) => {
+const setPostLanguage = (text, defaultLanguage) => {
   const lngDetector = new LanguageDetect()
   lngDetector.setLanguageType('iso2')
-  return lngDetector.detect(removeHtmlTags(text), 1)[0][0]
+  let languages = lngDetector.detect(removeHtmlTags(text), 1)
+  if (!(Array.isArray(languages) && languages.length > 0)) {
+    languages = [[defaultLanguage, 1.0]]
+  }
+  return languages[0][0]
 }
 
 export default {
   Mutation: {
     CreatePost: async (resolve, root, args, context, info) => {
-      args.language = await setPostLanguage(args.content)
+      args.language = await setPostLanguage(args.content, context.user.locale)
       return resolve(root, args, context, info)
     },
     UpdatePost: async (resolve, root, args, context, info) => {
-      args.language = await setPostLanguage(args.content)
+      args.language = await setPostLanguage(args.content, context.user.locale)
       return resolve(root, args, context, info)
     },
   },