1 files changed, 83 insertions, 0 deletions
diff --git a/app/assets/javascripts/diffs/store/getters.js b/app/assets/javascripts/diffs/store/getters.js
index 855de79adf8..c7b9b1a16e6 100644
--- a/app/assets/javascripts/diffs/store/getters.js
+++ b/app/assets/javascripts/diffs/store/getters.js
@@ -1,5 +1,7 @@
 import _ from 'underscore';
+import { convertObjectPropsToCamelCase } from '~/lib/utils/common_utils';
 import { PARALLEL_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE } from '../constants';
+import { getDiffRefsByLineCode } from './utils';
 
 export const isParallelView = state => state.diffViewType === PARALLEL_DIFF_VIEW_TYPE;
 
@@ -56,6 +58,87 @@ export const getDiffFileDiscussions = (state, getters, rootState, rootGetters) =
       discussion.diff_discussion && _.isEqual(discussion.diff_file.file_hash, diff.fileHash),
   ) || [];
 
+/**
+ * Returns an Object with discussions by their diff line code
+ * To avoid rendering outdated discussions on the Changes tab we should do a bunch of SHA
+ * comparisions. `note.position.formatter` have the current version diff refs but
+ * `note.original_position.formatter` will have the first version's diff refs.
+ * If line diff refs matches with one of them, we should render it as a discussion on Changes tab.
+ *
+ * @param {Object} diff
+ * @returns {Array}
+ */
+export const discussionsByLineCode = (state, getters, rootState, rootGetters) => {
+  const diffRefsByLineCode = getDiffRefsByLineCode(state.diffFiles);
+
+  return rootGetters.discussions.reduce((acc, note) => {
+    const isDiffDiscussion = note.diff_discussion;
+    const hasLineCode = note.line_code;
+    const isResolvable = note.resolvable;
+
+    if (isDiffDiscussion && hasLineCode && isResolvable) {
+      const diffRefs = diffRefsByLineCode[note.line_code];
+      if (diffRefs) {
+        const refs = convertObjectPropsToCamelCase(note.position.formatter);
+        const originalRefs = convertObjectPropsToCamelCase(note.original_position.formatter);
+
+        if (_.isEqual(refs, diffRefs) || _.isEqual(originalRefs, diffRefs)) {
+          const lineCode = note.line_code;
+
+          if (acc[lineCode]) {
+            acc[lineCode].push(note);
+          } else {
+            acc[lineCode] = [note];
+          }
+        }
+      }
+    }
+
+    return acc;
+  }, {});
+};
+
+export const singleDiscussionByLineCode = (state, getters) => lineCode => {
+  if (!lineCode) return [];
+  const discussions = getters.discussionsByLineCode;
+  return discussions[lineCode] || [];
+};
+
+export const shouldRenderParallelCommentRow = (state, getters) => line => {
+  const leftLineCode = line.left.lineCode;
+  const rightLineCode = line.right.lineCode;
+  const leftDiscussions = getters.singleDiscussionByLineCode(leftLineCode);
+  const rightDiscussions = getters.singleDiscussionByLineCode(rightLineCode);
+  const hasDiscussion = leftDiscussions.length || rightDiscussions.length;
+
+  const hasExpandedDiscussionOnLeft = leftDiscussions.length
+    ? leftDiscussions.every(discussion => discussion.expanded)
+    : false;
+  const hasExpandedDiscussionOnRight = rightDiscussions.length
+    ? rightDiscussions.every(discussion => discussion.expanded)
+    : false;
+
+  if (hasDiscussion && (hasExpandedDiscussionOnLeft || hasExpandedDiscussionOnRight)) {
+    return true;
+  }
+
+  const hasCommentFormOnLeft = state.diffLineCommentForms[leftLineCode];
+  const hasCommentFormOnRight = state.diffLineCommentForms[rightLineCode];
+
+  return hasCommentFormOnLeft || hasCommentFormOnRight;
+};
+
+export const shouldRenderInlineCommentRow = (state, getters) => line => {
+  if (state.diffLineCommentForms[line.lineCode]) return true;
+
+  const lineDiscussions = getters.singleDiscussionByLineCode(line.lineCode);
+  if (lineDiscussions.length === 0) {
+    return false;
+  }
+
+  return lineDiscussions.every(discussion => discussion.expanded);
+};
+
 // prevent babel-plugin-rewire from generating an invalid default during karma∂ tests
 export const getDiffFileByHash = state => fileHash =>
   state.diffFiles.find(file => file.fileHash === fileHash);