3 files changed, 68 insertions, 21 deletions

diff --git a/app/assets/javascripts/notes/stores/actions.js b/app/assets/javascripts/notes/stores/actions.js
index 7eb10f647a0..c862a29ad9c 100644
--- a/app/assets/javascripts/notes/stores/actions.js
+++ b/app/assets/javascripts/notes/stores/actions.js
@@ -1,4 +1,3 @@
-/* eslint-disable @gitlab/require-string-literal-i18n-helpers */
 import $ from 'jquery';
 import Visibility from 'visibilityjs';
 import Vue from 'vue';
@@ -71,7 +70,7 @@ export const setUserData = ({ commit }, data) => commit(types.SET_USER_DATA, dat
 export const setLastFetchedAt = ({ commit }, data) => commit(types.SET_LAST_FETCHED_AT, data);
 
 export const setInitialNotes = ({ commit }, discussions) =>
-  commit(types.SET_INITIAL_DISCUSSIONS, discussions);
+  commit(types.ADD_OR_UPDATE_DISCUSSIONS, discussions);
 
 export const setTargetNoteHash = ({ commit }, data) => commit(types.SET_TARGET_NOTE_HASH, data);
 
@@ -90,14 +89,51 @@ export const fetchDiscussions = ({ commit, dispatch }, { path, filter, persistFi
       ? { params: { notes_filter: filter, persist_filter: persistFilter } }
       : null;
 
+  if (window.gon?.features?.paginatedIssueDiscussions) {
+    return dispatch('fetchDiscussionsBatch', { path, config, perPage: 20 });
+  }
+
   return axios.get(path, config).then(({ data }) => {
-    commit(types.SET_INITIAL_DISCUSSIONS, data);
+    commit(types.ADD_OR_UPDATE_DISCUSSIONS, data);
     commit(types.SET_FETCHING_DISCUSSIONS, false);
 
     dispatch('updateResolvableDiscussionsCounts');
   });
 };
 
+export const fetchDiscussionsBatch = ({ commit, dispatch }, { path, config, cursor, perPage }) => {
+  const params = { ...config?.params, per_page: perPage };
+
+  if (cursor) {
+    params.cursor = cursor;
+  }
+
+  return axios.get(path, { params }).then(({ data, headers }) => {
+    commit(types.ADD_OR_UPDATE_DISCUSSIONS, data);
+
+    if (headers['x-next-page-cursor']) {
+      const nextConfig = { ...config };
+
+      if (config?.params?.persist_filter) {
+        delete nextConfig.params.notes_filter;
+        delete nextConfig.params.persist_filter;
+      }
+
+      return dispatch('fetchDiscussionsBatch', {
+        path,
+        config: nextConfig,
+        cursor: headers['x-next-page-cursor'],
+        perPage: Math.min(Math.round(perPage * 1.5), 100),
+      });
+    }
+
+    commit(types.SET_FETCHING_DISCUSSIONS, false);
+    dispatch('updateResolvableDiscussionsCounts');
+
+    return undefined;
+  });
+};
+
 export const updateDiscussion = ({ commit, state }, discussion) => {
   commit(types.UPDATE_DISCUSSION, discussion);
 
@@ -621,7 +657,7 @@ export const submitSuggestion = (
       const flashMessage = errorMessage || defaultMessage;
 
       createFlash({
-        message: __(flashMessage),
+        message: flashMessage,
         parent: flashContainer,
       });
     })
@@ -657,7 +693,7 @@ export const submitSuggestionBatch = ({ commit, dispatch, state }, { message, fl
       const flashMessage = errorMessage || defaultMessage;
 
       createFlash({
-        message: __(flashMessage),
+        message: flashMessage,
         parent: flashContainer,
       });
     })
diff --git a/app/assets/javascripts/notes/stores/mutation_types.js b/app/assets/javascripts/notes/stores/mutation_types.js
index 2e8b728e013..fcd2846ff0d 100644
--- a/app/assets/javascripts/notes/stores/mutation_types.js
+++ b/app/assets/javascripts/notes/stores/mutation_types.js
@@ -1,11 +1,11 @@
 export const ADD_NEW_NOTE = 'ADD_NEW_NOTE';
 export const ADD_NEW_REPLY_TO_DISCUSSION = 'ADD_NEW_REPLY_TO_DISCUSSION';
+export const ADD_OR_UPDATE_DISCUSSIONS = 'ADD_OR_UPDATE_DISCUSSIONS';
 export const DELETE_NOTE = 'DELETE_NOTE';
 export const REMOVE_PLACEHOLDER_NOTES = 'REMOVE_PLACEHOLDER_NOTES';
 export const SET_NOTES_DATA = 'SET_NOTES_DATA';
 export const SET_NOTEABLE_DATA = 'SET_NOTEABLE_DATA';
 export const SET_USER_DATA = 'SET_USER_DATA';
-export const SET_INITIAL_DISCUSSIONS = 'SET_INITIAL_DISCUSSIONS';
 export const SET_LAST_FETCHED_AT = 'SET_LAST_FETCHED_AT';
 export const SET_TARGET_NOTE_HASH = 'SET_TARGET_NOTE_HASH';
 export const SHOW_PLACEHOLDER_NOTE = 'SHOW_PLACEHOLDER_NOTE';
diff --git a/app/assets/javascripts/notes/stores/mutations.js b/app/assets/javascripts/notes/stores/mutations.js
index c5fa34dfedd..1a99750ddb3 100644
--- a/app/assets/javascripts/notes/stores/mutations.js
+++ b/app/assets/javascripts/notes/stores/mutations.js
@@ -129,8 +129,8 @@ export default {
     Object.assign(state, { userData: data });
   },
 
-  [types.SET_INITIAL_DISCUSSIONS](state, discussionsData) {
-    const discussions = discussionsData.reduce((acc, d) => {
+  [types.ADD_OR_UPDATE_DISCUSSIONS](state, discussionsData) {
+    discussionsData.forEach((d) => {
       const discussion = { ...d };
       const diffData = {};
 
@@ -145,27 +145,38 @@ export default {
       // To support legacy notes, should be very rare case.
       if (discussion.individual_note && discussion.notes.length > 1) {
         discussion.notes.forEach((n) => {
-          acc.push({
+          const newDiscussion = {
             ...discussion,
             ...diffData,
             notes: [n], // override notes array to only have one item to mimick individual_note
-          });
+          };
+          const oldDiscussion = state.discussions.find(
+            (existingDiscussion) =>
+              existingDiscussion.id === discussion.id && existingDiscussion.notes[0].id === n.id,
+          );
+
+          if (oldDiscussion) {
+            state.discussions.splice(state.discussions.indexOf(oldDiscussion), 1, newDiscussion);
+          } else {
+            state.discussions.push(newDiscussion);
+          }
         });
       } else {
-        const oldNote = utils.findNoteObjectById(state.discussions, discussion.id);
+        const oldDiscussion = utils.findNoteObjectById(state.discussions, discussion.id);
 
-        acc.push({
-          ...discussion,
-          ...diffData,
-          expanded: oldNote ? oldNote.expanded : discussion.expanded,
-        });
+        if (oldDiscussion) {
+          state.discussions.splice(state.discussions.indexOf(oldDiscussion), 1, {
+            ...discussion,
+            ...diffData,
+            expanded: oldDiscussion.expanded,
+          });
+        } else {
+          state.discussions.push({ ...discussion, ...diffData });
+        }
       }
-
-      return acc;
-    }, []);
-
-    Object.assign(state, { discussions });
+    });
   },
+
   [types.SET_LAST_FETCHED_AT](state, fetchedAt) {
     Object.assign(state, { lastFetchedAt: fetchedAt });
   },