Handle IgnoreUser mutation errors

We now check if the IgnoreUser mutation returned an error before
updating the apollo store. If the mutation returns an error we keep
the store as it is, otherwise the user is added to the ignore list.

plugins/talk-plugin-ignore-user/client/index.js

@@ -3,6 +3,7 @@ import IgnoreUserConfirmation from './containers/IgnoreUserConfirmation';
 import IgnoredUserSection from './containers/IgnoredUserSection';
 import translations from './translations.yml';
 import update from 'immutability-helper';
+import get from 'lodash/get';
 
 export default {
   slots: {
@@ -14,7 +15,11 @@ export default {
   mutations: {
     IgnoreUser: ({variables}) => ({
       updateQueries: {
-        CoralEmbedStream_Embed: (previousData) => {
+        CoralEmbedStream_Embed: (previousData, {mutationResult: {data: {ignoreUser}}}) => {
+          if (get(ignoreUser, 'errors.length')) {
+            return previousData;
+          }
+
           const ignoredUserId = variables.id;
           const updated = update(previousData, {me: {ignoredUsers: {$push: [{
             id: ignoredUserId,