From 49e3ec5e93c9f314650695290f965b563c5b5a55 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Sat, 25 Dec 2021 12:41:05 +0100
Subject: [PATCH] Message List: Drop redundant code

---
 src/components/middle/MessageList.tsx         | 11 ++---------
 src/components/middle/hooks/useScrollHooks.ts |  7 +------
 src/components/ui/InfiniteScroll.tsx          |  2 --
 3 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/src/components/middle/MessageList.tsx b/src/components/middle/MessageList.tsx
index d78a88ed4..7127ecb2a 100644
--- a/src/components/middle/MessageList.tsx
+++ b/src/components/middle/MessageList.tsx
@@ -327,11 +327,6 @@ const MessageList: FC<OwnProps & StateProps & DispatchProps> = ({
     const container = containerRef.current!;
     listItemElementsRef.current = Array.from(container.querySelectorAll<HTMLDivElement>('.message-list-item'));
 
-    // TODO Consider removing
-    if (!container.offsetParent) {
-      return;
-    }
-
     const hasLastMessageChanged = (
       messageIds && prevMessageIds && messageIds[messageIds.length - 1] !== prevMessageIds[prevMessageIds.length - 1]
     );
@@ -362,8 +357,7 @@ const MessageList: FC<OwnProps & StateProps & DispatchProps> = ({
     }
 
     const { scrollTop, scrollHeight, offsetHeight } = container;
-    // TODO Consider `scrollOffset = scrollHeight - scrollTop`
-    const scrollOffset = scrollOffsetRef.current!;
+    const scrollOffset = scrollOffsetRef.current;
     const lastItemElement = listItemElementsRef.current[listItemElementsRef.current.length - 1];
 
     let bottomOffset = scrollOffset - (prevContainerHeight || offsetHeight);
@@ -405,8 +399,7 @@ const MessageList: FC<OwnProps & StateProps & DispatchProps> = ({
     }
 
     const isResized = prevContainerHeight !== undefined && prevContainerHeight !== containerHeight;
-    // TODO Look up within active transition slide
-    const anchor = anchorIdRef.current && document.getElementById(anchorIdRef.current);
+    const anchor = anchorIdRef.current && container.querySelector(`#${anchorIdRef.current}`);
     const unreadDivider = (
       !anchor
       && memoUnreadDividerBeforeIdRef.current
diff --git a/src/components/middle/hooks/useScrollHooks.ts b/src/components/middle/hooks/useScrollHooks.ts
index 2a6a11aea..f7591019f 100644
--- a/src/components/middle/hooks/useScrollHooks.ts
+++ b/src/components/middle/hooks/useScrollHooks.ts
@@ -6,9 +6,8 @@ import { LoadMoreDirection } from '../../../types';
 import { MessageListType } from '../../../global/types';
 
 import { LOCAL_MESSAGE_ID_BASE, MESSAGE_LIST_SLICE } from '../../../config';
-import { IS_MAC_OS, IS_SCROLL_PATCH_NEEDED, MESSAGE_LIST_SENSITIVE_AREA } from '../../../util/environment';
+import { IS_SCROLL_PATCH_NEEDED, MESSAGE_LIST_SENSITIVE_AREA } from '../../../util/environment';
 import { debounce } from '../../../util/schedulers';
-import resetScroll from '../../../util/resetScroll';
 import { useIntersectionObserver, useOnIntersect } from '../../../hooks/useIntersectionObserver';
 import useOnChange from '../../../hooks/useOnChange';
 
@@ -100,12 +99,8 @@ export default function useScrollHooks(
         isScrollPatchNeededRef.current = true;
       }
 
-      // TODO Consider removing
-      resetScroll(containerRef.current!);
       loadMoreBackwards();
     } else if (target.className === 'forwards-trigger') {
-      // TODO Consider removing
-      resetScroll(containerRef.current!);
       loadMoreForwards();
     }
   });
diff --git a/src/components/ui/InfiniteScroll.tsx b/src/components/ui/InfiniteScroll.tsx
index 091f7c343..817415d06 100644
--- a/src/components/ui/InfiniteScroll.tsx
+++ b/src/components/ui/InfiniteScroll.tsx
@@ -165,7 +165,6 @@ const InfiniteScroll: FC<OwnProps> = ({
             stateRef.current.currentAnchor = nextAnchor;
             stateRef.current.currentAnchorTop = nextAnchorTop;
             isUpdated = true;
-            resetScroll(container);
             loadMoreForwards();
           }
         }
@@ -186,7 +185,6 @@ const InfiniteScroll: FC<OwnProps> = ({
             stateRef.current.currentAnchor = nextAnchor;
             stateRef.current.currentAnchorTop = nextAnchorTop;
             isUpdated = true;
-            resetScroll(container);
             loadMoreBackwards();
           }
         }