Fix live comments behavior on paginated comments and threads (#2334)

* livecomments: patches for paginated comments; broader ViewMoreReplies component

live comments:
- don't show the thread button for thread comments that are shown as full items (top level)
- don't try to count/inject on paginated comments, just show the live comments dot
- dedupe new comments being fetched with already existing comments, useful for just showing the dot, but not the button

comments:
- live comments dot now appears on both paginated and bottomed out comments
-- merge ViewAllReplies with ReplyToAnotherPage

* fix thread comment recognition, now based on depth

components/comment.js

@@ -261,7 +261,7 @@ export default function Comment ({
       </div>
       {collapse !== 'yep' && (
         bottomedOut
-          ? <div className={styles.children}><div className={classNames(styles.comment, 'mt-3')}><ReplyOnAnotherPage item={item} /></div></div>
+          ? <div className={styles.children}><div className={classNames(styles.comment, 'mt-3 pb-2')}><ViewMoreReplies item={item} navigateRoot /></div></div>
           : (
             <div className={styles.children}>
               {item.outlawed && !me?.privates?.wildWestMode
@@ -281,7 +281,11 @@ export default function Comment ({
                       {item.comments.comments.map((item) => (
                         <Comment depth={depth + 1} key={item.id} item={item} rootLastCommentAt={rootLastCommentAt} />
                       ))}
-                      {item.comments.comments.length < item.nDirectComments && <ViewAllReplies id={item.id} nhas={item.ncomments} />}
+                      {item.comments.comments.length < item.nDirectComments && (
+                        <div className={`d-block ${styles.comment} pb-2 ps-3`}>
+                          <ViewMoreReplies item={item} />
+                        </div>
+                      )}
                     </>
                     )
                   : null}
@@ -294,31 +298,24 @@ export default function Comment ({
   )
 }
 
-export function ViewAllReplies ({ id, nshown, nhas }) {
-  const text = `view all ${nhas} replies`
-
-  return (
-    <div className={`d-block fw-bold ${styles.comment} pb-2 ps-3`}>
-      <Link href={`/items/${id}`} as={`/items/${id}`} className='text-muted'>
-        {text}
-      </Link>
-    </div>
-  )
-}
-
-function ReplyOnAnotherPage ({ item }) {
+export function ViewMoreReplies ({ item, navigateRoot = false }) {
   const root = useRoot()
-  const rootId = commentSubTreeRootId(item, root)
   const { cache } = useApolloClient()
+  const id = navigateRoot ? commentSubTreeRootId(item, root) : item.id
 
-  let text = 'reply on another page'
-  if (item.ncomments > 0) {
-    text = `view all ${item.ncomments} replies`
-  }
+  const href = `/items/${id}` + (navigateRoot ? '' : `?commentId=${item.id}`)
+
+  const text = navigateRoot && item.ncomments === 0
+    ? 'reply on another page'
+    : `view all ${item.ncomments} replies`
 
   return (
     <Link
+      href={href}
+      as={`/items/${id}`}
+      className='fw-bold d-flex align-items-center gap-2 text-muted'
       onClick={() => {
+        if (!item.newComments?.length) return
         // clear new comments going to another page
         cache.writeFragment({
           id: `Item:${item.id}`,
@@ -331,9 +328,6 @@ function ReplyOnAnotherPage ({ item }) {
           }
         })
       }}
-      href={`/items/${rootId}?commentId=${item.id}`}
-      as={`/items/${rootId}`}
-      className='pb-2 fw-bold d-flex align-items-center gap-2 text-muted'
     >
       {text}
       {item.newComments?.length > 0 && <div className={styles.newCommentDot} />}

components/show-new-comments.js

@@ -74,6 +74,10 @@ function traverseNewComments (client, item, onLevel, currentDepth, inSubtree) {
   // if we're at the depth limit, stop traversing, we've reached the bottom of the visible thread
   if (currentDepth >= COMMENT_DEPTH_LIMIT) return
 
+  // if the current item shows less comments than its nDirectComments, it's paginated
+  // we don't want to count/inject new comments in paginated items, as they shouldn't be visible
+  if (item.comments?.comments?.length < item.nDirectComments) return
+
   if (item.newComments && item.newComments.length > 0) {
     const dedupedNewComments = dedupeNewComments(item.newComments, item.comments?.comments)
 
@@ -161,8 +165,8 @@ export function ShowNewComments ({ topLevel, item, sort, depth = 0 }) {
   const client = useApolloClient()
   const ref = useRef(null)
 
-  // a thread is a top-level comment
-  const thread = item.path?.split('.').length === 2
+  // a thread comment is a comment at depth 1 (parent)
+  const thread = depth === 1
 
   // recurse through all new comments and their children
   // if the item is a thread, we also consider all of their existing children

components/use-live-comments.js

@@ -7,12 +7,13 @@ import { itemUpdateQuery, commentUpdateFragment, getLatestCommentCreatedAt } fro
 const POLL_INTERVAL = 1000 * 10 // 10 seconds
 
 // merge new comment into item's newComments
-// and prevent duplicates by checking if the comment is already in item's newComments
+// and prevent duplicates by checking if the comment is already in item's newComments or existing comments
 function mergeNewComment (item, newComment) {
   const existingNewComments = item.newComments || []
+  const existingComments = item.comments?.comments || []
 
-  // is the incoming new comment already in item's new comments?
-  if (existingNewComments.includes(newComment.id)) {
+  // is the incoming new comment already in item's new comments or existing comments?
+  if (existingNewComments.includes(newComment.id) || existingComments.some(comment => comment.id === newComment.id)) {
     return item
   }