[Perf] Remove some redundant array spreads

src/components/common/helpers/renderText.tsx

@@ -70,12 +70,14 @@ function escapeHtml(textParts: TextPart[]): TextPart[] {
   const divEl = document.createElement('div');
   return textParts.reduce((result, part) => {
     if (typeof part !== 'string') {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     divEl.innerText = part;
+    result.push(divEl.innerHTML);
 
-    return [...result, divEl.innerHTML];
+    return result;
   }, [] as TextPart[]);
 }
 
@@ -86,7 +88,8 @@ function replaceEmojis(textParts: TextPart[], size: 'big' | 'small', type: 'jsx'
 
   return textParts.reduce((result, part) => {
     if (typeof part !== 'string') {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     part = fixNonStandardEmoji(part);
@@ -129,12 +132,13 @@ function replaceEmojis(textParts: TextPart[], size: 'big' | 'small', type: 'jsx'
 }
 
 function addLineBreaks(textParts: TextPart[], type: 'jsx' | 'html'): TextPart[] {
-  return textParts.reduce((result, part) => {
+  return textParts.reduce((result: TextPart[], part) => {
     if (typeof part !== 'string') {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
-    return [...result, ...part
+    const splittenParts = part
       .split(/\r\n|\r|\n/g)
       .reduce((parts: TextPart[], line: string, i, source) => {
         // This adds non-breaking space if line was indented with spaces, to preserve the indentation
@@ -149,21 +153,25 @@ function addLineBreaks(textParts: TextPart[], type: 'jsx' | 'html'): TextPart[]
         }
 
         return parts;
-      }, [])];
-  }, [] as TextPart[]);
+      }, []);
+
+    return [...result, ...splittenParts];
+  }, []);
 }
 
 function addHighlight(textParts: TextPart[], highlight: string | undefined): TextPart[] {
   return textParts.reduce((result, part) => {
     if (typeof part !== 'string' || !highlight) {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     const lowerCaseText = part.toLowerCase();
     const queryPosition = lowerCaseText.indexOf(highlight.toLowerCase());
     const nextSymbol = lowerCaseText[queryPosition + highlight.length];
     if (queryPosition < 0 || (nextSymbol && nextSymbol.match(RE_LETTER_OR_DIGIT))) {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     const newParts: TextPart[] = [];
@@ -184,12 +192,14 @@ const RE_LINK = new RegExp(`${RE_LINK_TEMPLATE}|${RE_MENTION_TEMPLATE}`, 'ig');
 function addLinks(textParts: TextPart[]): TextPart[] {
   return textParts.reduce((result, part) => {
     if (typeof part !== 'string') {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     const links = part.match(RE_LINK);
     if (!links || !links.length) {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     const content: TextPart[] = [];
@@ -226,7 +236,8 @@ function addLinks(textParts: TextPart[]): TextPart[] {
 function replaceSimpleMarkdown(textParts: TextPart[], type: 'jsx' | 'html'): TextPart[] {
   return textParts.reduce((result, part) => {
     if (typeof part !== 'string') {
-      return [...result, part];
+      result.push(part);
+      return result;
     }
 
     const parts = part.split(SIMPLE_MARKDOWN_REGEX);

src/components/left/settings/folders/SettingsFoldersChatFilters.tsx

@@ -72,11 +72,9 @@ const SettingsFoldersChatFilters: FC<OwnProps & StateProps & DispatchProps> = ({
     }
 
     return [
-      ...(activeChatArrays
-        ? [...activeChatArrays.pinnedChats, ...activeChatArrays.otherChats]
-        : []
-      ),
-      ...(archivedChatArrays ? archivedChatArrays.otherChats : []),
+      ...(activeChatArrays?.pinnedChats || []),
+      ...(activeChatArrays?.otherChats || []),
+      ...(archivedChatArrays?.otherChats || []),
     ];
   }, [chatsById, listIds, orderedPinnedIds, archivedListIds, archivedPinnedIds]);
 
@@ -140,8 +138,10 @@ const SettingsFoldersChatFilters: FC<OwnProps & StateProps & DispatchProps> = ({
     }
   }, [mode, selectedChatIds, dispatch]);
 
-  useHistoryBack(isActive, onReset, onScreenSelect,
-    mode === 'included' ? SettingsScreens.FoldersIncludedChats : SettingsScreens.FoldersExcludedChats);
+  useHistoryBack(
+    isActive, onReset, onScreenSelect,
+    mode === 'included' ? SettingsScreens.FoldersIncludedChats : SettingsScreens.FoldersExcludedChats,
+  );
 
   if (!displayedIds) {
     return <Loading />;

src/components/main/ForwardPicker.tsx

@@ -45,34 +45,29 @@ const ForwardPicker: FC<OwnProps & StateProps & DispatchProps> = ({
   const filterRef = useRef<HTMLInputElement>(null);
 
   const chatIds = useMemo(() => {
-    const listIds = [
-      ...(activeListIds || []),
-      ...(archivedListIds || []),
-    ];
+    const listIds = [...(activeListIds || []), ...(archivedListIds || [])];
 
     let priorityIds = pinnedIds || [];
     if (currentUserId) {
       priorityIds = unique([currentUserId, ...priorityIds]);
     }
 
-    return sortChatIds([
-      ...listIds.filter((id) => {
-        const chat = chatsById[id];
-        if (!chat) {
-          return true;
-        }
+    return sortChatIds(listIds.filter((id) => {
+      const chat = chatsById[id];
+      if (!chat) {
+        return true;
+      }
 
-        if (!getCanPostInChat(chat, MAIN_THREAD_ID)) {
-          return false;
-        }
+      if (!getCanPostInChat(chat, MAIN_THREAD_ID)) {
+        return false;
+      }
 
-        if (!filter) {
-          return true;
-        }
+      if (!filter) {
+        return true;
+      }
 
-        return searchWords(getChatTitle(lang, chatsById[id], undefined, id === currentUserId), filter);
-      }),
-    ], chatsById, undefined, priorityIds);
+      return searchWords(getChatTitle(lang, chatsById[id], undefined, id === currentUserId), filter);
+    }), chatsById, undefined, priorityIds);
   }, [activeListIds, archivedListIds, chatsById, currentUserId, filter, lang, pinnedIds]);
 
   const handleSelectUser = useCallback((userId: string) => {

src/util/iteratees.ts

@@ -139,14 +139,6 @@ export function cloneDeep<T>(value: T): T {
   }, {} as T);
 }
 
-/**
- * Returns the index of the last element in the array where predicate is true, and -1 otherwise.
- *
- * @param array The source array to search in
- * @param predicate find calls predicate once for each element of the array, in descending
- * order, until it finds one where predicate returns true. If such an element is found,
- * findLastIndex immediately returns that element index. Otherwise, findLastIndex returns -1.
- */
 export function findLast<T>(array: Array<T>, predicate: (value: T, index: number, obj: T[]) => boolean): T | undefined {
   let cursor = array.length;