change of approach: create a new setting to limit message parsing

nazabucciarelli · nazabucciarelli · commit 0f75d73cdc0c · 2026-04-30T17:25:57.000-03:00
diff --git a/apps/meteor/client/components/message/content/attachments/QuoteAttachment.spec.tsx b/apps/meteor/client/components/message/content/attachments/QuoteAttachment.spec.tsx
@@ -2,8 +2,8 @@ import { render, screen } from '@testing-library/react';
 
 import { QuoteAttachment } from './QuoteAttachment';
 
-jest.mock('../../hooks/useMaxMessageParseSize', () => ({
-	useMaxMessageParseSize: () => 100,
+jest.mock('../../hooks/useMaxMarkdownParseLength', () => ({
+	useMaxMarkdownParseLength: () => 100,
 }));
 
 jest.mock('@rocket.chat/ui-contexts', () => ({
@@ -28,12 +28,12 @@ const baseAttachment = {
 };
 
 describe('QuoteAttachment', () => {
-	it('renders MessageContentBody when text length is within maxMessageParseSize', () => {
+	it('renders MessageContentBody when text length is within maxMarkdownParseLength', () => {
 		render(<QuoteAttachment attachment={baseAttachment as any} />);
 		expect(screen.getByTestId('message-content-body')).toBeInTheDocument();
 	});
 
-	it('renders plain text when text exceeds maxMessageParseSize', () => {
+	it('renders plain text when text exceeds maxMarkdownParseLength', () => {
 		const longText = 'a'.repeat(101);
 		const attachment = { ...baseAttachment, text: longText };
 
diff --git a/apps/meteor/client/components/message/content/attachments/QuoteAttachment.tsx b/apps/meteor/client/components/message/content/attachments/QuoteAttachment.tsx
@@ -13,7 +13,7 @@ import AttachmentAuthorName from './structure/AttachmentAuthorName';
 import AttachmentContent from './structure/AttachmentContent';
 import AttachmentDetails from './structure/AttachmentDetails';
 import AttachmentInner from './structure/AttachmentInner';
-import { useMaxMessageParseSize } from '../../hooks/useMaxMessageParseSize';
+import { useMaxMarkdownParseLength } from '../../hooks/useMaxMarkdownParseLength';
 
 // TODO: remove this team collaboration
 const quoteStyles = css`
@@ -39,7 +39,7 @@ type QuoteAttachmentProps = {
 export const QuoteAttachment = ({ attachment }: QuoteAttachmentProps): ReactElement => {
 	const formatTime = useTimeAgo();
 	const displayAvatarPreference = useUserPreference<boolean>('displayAvatars');
-	const maxMessageParseSize = useMaxMessageParseSize();
+	const maxMarkdownParseLength = useMaxMarkdownParseLength();
 
 	return (
 		<>
@@ -73,11 +73,7 @@ export const QuoteAttachment = ({ attachment }: QuoteAttachmentProps): ReactElem
 							<Attachments attachments={attachment.attachments} id={attachment.attachments[0]?.title_link} />
 						</AttachmentInner>
 					)}
-					{attachment.text.length <= maxMessageParseSize && attachment.md ? (
-						<MessageContentBody md={attachment.md} />
-					) : (
-						attachment.text.substring(attachment.text.indexOf('\n') + 1)
-					)}
+					{attachment.text.length <= maxMarkdownParseLength && attachment.md ? <MessageContentBody md={attachment.md} /> : attachment.text}
 				</AttachmentDetails>
 			</AttachmentContent>
 		</>
diff --git a/apps/meteor/client/components/message/hooks/useMaxMarkdownParseLength.ts b/apps/meteor/client/components/message/hooks/useMaxMarkdownParseLength.ts
@@ -0,0 +1,18 @@
+import { useSetting } from '@rocket.chat/ui-contexts';
+import { useMemo } from 'react';
+
+/**
+ * Returns the maximum number of characters a message can have for markdown parsing.
+ * Returns Infinity when the setting is 0 or negative, meaning the limit is disabled
+ * and all messages will be parsed regardless of length.
+ */
+export const useMaxMarkdownParseLength = (): number => {
+	const settingValue = useSetting('Message_MaxMarkdownParseLength', 0);
+
+	return useMemo(() => {
+		if (typeof settingValue !== 'number' || settingValue <= 0) {
+			return Infinity;
+		}
+		return settingValue;
+	}, [settingValue]);
+};
diff --git a/apps/meteor/client/components/message/hooks/useMaxMessageParseSize.ts b/apps/meteor/client/components/message/hooks/useMaxMessageParseSize.ts
diff --git a/apps/meteor/client/components/message/hooks/useNormalizedMessage.spec.ts b/apps/meteor/client/components/message/hooks/useNormalizedMessage.spec.ts
@@ -32,7 +32,7 @@ describe('useNormalizedMessage', () => {
 		mockParseMessageTextToAstMarkdown.mockClear();
 	});
 
-	it('should skip parsing and returns PARAGRAPH node when msg exceeds maxMessageParseSize', () => {
+	it('should skip parsing and returns PARAGRAPH node when msg exceeds maxMarkdownParseLength', () => {
 		const longMsg = 'a'.repeat(101);
 		const message = { ...baseMessage, msg: longMsg };
 
@@ -47,7 +47,7 @@ describe('useNormalizedMessage', () => {
 		]);
 	});
 
-	it('should call parseMessageTextToAstMarkdown when msg is within maxMessageParseSize', () => {
+	it('should call parseMessageTextToAstMarkdown when msg is within maxMarkdownParseLength', () => {
 		const message = { ...baseMessage, msg: 'Hello world' };
 
 		renderHook(() => useNormalizedMessage(message as any, 100));
diff --git a/apps/meteor/client/components/message/hooks/useNormalizedMessage.ts b/apps/meteor/client/components/message/hooks/useNormalizedMessage.ts
@@ -57,7 +57,10 @@ const normalizeAttachments = (attachments: MessageAttachment[], name?: string, t
 	});
 };
 
-export const useNormalizedMessage = <TMessage extends IMessage>(message: TMessage, maxMessageParseSize: number): MessageWithMdEnforced => {
+export const useNormalizedMessage = <TMessage extends IMessage>(
+	message: TMessage,
+	maxMarkdownParseLength: number,
+): MessageWithMdEnforced => {
 	const katex = useMessageListKatex();
 	const katexEnabled = !!katex;
 	const customDomains = useAutoLinkDomains();
@@ -77,7 +80,7 @@ export const useNormalizedMessage = <TMessage extends IMessage>(message: TMessag
 			}),
 		};
 
-		if (message.msg && message.msg.length > maxMessageParseSize) {
+		if (message.msg && message.msg.length > maxMarkdownParseLength) {
 			return {
 				...message,
 				md: [
@@ -115,6 +118,6 @@ export const useNormalizedMessage = <TMessage extends IMessage>(message: TMessag
 		katex?.parenthesisSyntaxEnabled,
 		message,
 		autoTranslateOptions,
-		maxMessageParseSize,
+		maxMarkdownParseLength,
 	]);
 };
diff --git a/apps/meteor/client/components/message/variants/ThreadMessagePreview.tsx b/apps/meteor/client/components/message/variants/ThreadMessagePreview.tsx
@@ -31,7 +31,7 @@ import { useGoToThread } from '../../../views/room/hooks/useGoToThread';
 import Emoji from '../../Emoji';
 import { useShowTranslated } from '../list/MessageListContext';
 import ThreadMessagePreviewBody from './threadPreview/ThreadMessagePreviewBody';
-import { useMaxMessageParseSize } from '../hooks/useMaxMessageParseSize';
+import { useMaxMarkdownParseLength } from '../hooks/useMaxMarkdownParseLength';
 
 type ThreadMessagePreviewProps = {
 	message: IThreadMessage;
@@ -53,8 +53,8 @@ const ThreadMessagePreview = ({ message, showUserAvatar, sequential, ...props }:
 
 	const messageType = parentMessage.isSuccess ? MessageTypes.getType(parentMessage.data) : null;
 
-	const maxMessageParseSize = useMaxMessageParseSize();
-	const messageBody = useMessageBody(parentMessage.data, maxMessageParseSize);
+	const maxMarkdownParseLength = useMaxMarkdownParseLength();
+	const messageBody = useMessageBody(parentMessage.data, maxMarkdownParseLength);
 
 	const previewMessage = isParsedMessage(messageBody) ? { md: messageBody } : { msg: messageBody };
 
diff --git a/apps/meteor/client/components/message/variants/room/RoomMessageContent.tsx b/apps/meteor/client/components/message/variants/room/RoomMessageContent.tsx
@@ -18,7 +18,7 @@ import MessageActions from '../../content/MessageActions';
 import Reactions from '../../content/Reactions';
 import ThreadMetrics from '../../content/ThreadMetrics';
 import UrlPreviews from '../../content/UrlPreviews';
-import { useMaxMessageParseSize } from '../../hooks/useMaxMessageParseSize';
+import { useMaxMarkdownParseLength } from '../../hooks/useMaxMarkdownParseLength';
 import { useNormalizedMessage } from '../../hooks/useNormalizedMessage';
 import { useOembedLayout } from '../../hooks/useOembedLayout';
 import { useSubscriptionFromMessageQuery } from '../../hooks/useSubscriptionFromMessageQuery';
@@ -43,9 +43,9 @@ const RoomMessageContent = ({ message, unread, all, mention, searchText }: RoomM
 	const messageUser = { ...message.u, roles: [], ...useUserPresence(message.u._id) };
 	const chat = useChat();
 	const { t } = useTranslation();
-	const maxMessageParseSize = useMaxMessageParseSize();
+	const maxMarkdownParseLength = useMaxMarkdownParseLength();
 
-	const normalizedMessage = useNormalizedMessage(message, maxMessageParseSize);
+	const normalizedMessage = useNormalizedMessage(message, maxMarkdownParseLength);
 	const isMessageEncrypted = encrypted && normalizedMessage?.e2e === 'pending';
 
 	const quotes = normalizedMessage?.attachments?.filter(isQuoteAttachment) || [];
diff --git a/apps/meteor/client/components/message/variants/thread/ThreadMessageContent.tsx b/apps/meteor/client/components/message/variants/thread/ThreadMessageContent.tsx
@@ -15,7 +15,7 @@ import Location from '../../content/Location';
 import MessageActions from '../../content/MessageActions';
 import Reactions from '../../content/Reactions';
 import UrlPreviews from '../../content/UrlPreviews';
-import { useMaxMessageParseSize } from '../../hooks/useMaxMessageParseSize';
+import { useMaxMarkdownParseLength } from '../../hooks/useMaxMarkdownParseLength';
 import { useNormalizedMessage } from '../../hooks/useNormalizedMessage';
 import { useOembedLayout } from '../../hooks/useOembedLayout';
 import { useSubscriptionFromMessageQuery } from '../../hooks/useSubscriptionFromMessageQuery';
@@ -34,11 +34,11 @@ const ThreadMessageContent = ({ message }: ThreadMessageContentProps): ReactElem
 	const uid = useUserId();
 	const { enabled: readReceiptEnabled } = useMessageListReadReceipts();
 	const messageUser = { ...message.u, roles: [], ...useUserPresence(message.u._id) };
-	const maxMessageParseSize = useMaxMessageParseSize();
+	const maxMarkdownParseLength = useMaxMarkdownParseLength();
 
 	const { t } = useTranslation();
 
-	const normalizedMessage = useNormalizedMessage(message, maxMessageParseSize);
+	const normalizedMessage = useNormalizedMessage(message, maxMarkdownParseLength);
 
 	const isMessageEncrypted = encrypted && normalizedMessage?.e2e === 'pending';
 
diff --git a/apps/meteor/client/lib/constants.ts b/apps/meteor/client/lib/constants.ts
@@ -3,4 +3,3 @@ export const BIO_TEXT_MAX_LENGTH = 260;
 export const VIDEOCONF_STACK_MAX_USERS = 6;
 export const NAVIGATION_REGION_ID = 'navigation-region';
 export const MAX_FILE_SIZE_PREVIEW = 10485760; // 10MB
-export const MESSAGE_PARSE_HARD_LIMIT = 20000;
diff --git a/apps/meteor/client/views/room/MessageList/hooks/useMessageBody.spec.ts b/apps/meteor/client/views/room/MessageList/hooks/useMessageBody.spec.ts
@@ -32,7 +32,7 @@ describe('useMessageBody', () => {
 		mockParseMessageTextToAstMarkdown.mockClear();
 	});
 
-	it('should return raw msg and skips parsing when msg exceeds maxMessageParseSize', () => {
+	it('should return raw msg and skips parsing when msg exceeds maxMarkdownParseLength', () => {
 		const longMsg = 'a'.repeat(101);
 		const message = { ...baseMessage, msg: longMsg, md: [{ type: 'PARAGRAPH', value: [] }] };
 
@@ -42,7 +42,7 @@ describe('useMessageBody', () => {
 		expect(mockParseMessageTextToAstMarkdown).not.toHaveBeenCalled();
 	});
 
-	it('should call parser when message has md and is within maxMessageParseSize', () => {
+	it('should call parser when message has md and is within maxMarkdownParseLength', () => {
 		const md = [{ type: 'PARAGRAPH', value: [] }];
 		const message = { ...baseMessage, msg: 'Hello world', md };
 		mockParseMessageTextToAstMarkdown.mockReturnValue({ ...message, md });
diff --git a/apps/meteor/client/views/room/MessageList/hooks/useMessageBody.tsx b/apps/meteor/client/views/room/MessageList/hooks/useMessageBody.tsx
@@ -6,7 +6,7 @@ import { useAutoLinkDomains } from './useAutoLinkDomains';
 import { useMessageListAutoTranslate } from '../../../../components/message/list/MessageListContext';
 import { parseMessageTextToAstMarkdown } from '../../../../lib/parseMessageTextToAstMarkdown';
 
-export const useMessageBody = (message: IMessage | undefined, maxMessageParseSize: number): string | Root => {
+export const useMessageBody = (message: IMessage | undefined, maxMarkdownParseLength: number): string | Root => {
 	const autoTranslateOptions = useMessageListAutoTranslate();
 	const customDomains = useAutoLinkDomains();
 
@@ -15,7 +15,7 @@ export const useMessageBody = (message: IMessage | undefined, maxMessageParseSiz
 			return '';
 		}
 
-		if (message.msg && message.msg.length > maxMessageParseSize) {
+		if (message.msg && message.msg.length > maxMarkdownParseLength) {
 			return message.msg;
 		}
 
@@ -43,5 +43,5 @@ export const useMessageBody = (message: IMessage | undefined, maxMessageParseSiz
 		}
 
 		return '';
-	}, [message, customDomains, autoTranslateOptions, maxMessageParseSize]);
+	}, [message, customDomains, autoTranslateOptions, maxMarkdownParseLength]);
 };
diff --git a/apps/meteor/server/settings/message.ts b/apps/meteor/server/settings/message.ts
@@ -168,8 +168,11 @@ export const createMessageSettings = () =>
 		await this.add('Message_MaxAllowedSize', 5000, {
 			type: 'int',
 			public: true,
-			// i18nDescription references MESSAGE_PARSE_HARD_LIMIT (20000) — update both if the constant changes
-			i18nDescription: 'Message_MaxAllowedSize_Description',
+		});
+		await this.add('Message_MaxMarkdownParseLength', 0, {
+			type: 'int',
+			public: true,
+			i18nDescription: 'Message_MaxMarkdownParseLength_Description',
 		});
 		await this.add('Message_AllowConvertLongMessagesToAttachment', true, {
 			type: 'boolean',
diff --git a/packages/i18n/src/locales/en.i18n.json b/packages/i18n/src/locales/en.i18n.json
@@ -3517,7 +3517,8 @@
   "Message_KeepHistory": "Keep Per Message Editing History",
   "Message_MaxAll": "Maximum Channel Size for ALL Message",
   "Message_MaxAllowedSize": "Maximum Allowed Characters Per Message",
-  "Message_MaxAllowedSize_Description": "Maximum number of characters allowed per message. Messages exceeding this limit will be displayed as plain text without markdown parsing. Note: markdown rendering is always disabled above 20,000 characters, regardless of this setting.",
+  "Message_MaxMarkdownParseLength": "Maximum Markdown Parsing Characters",
+  "Message_MaxMarkdownParseLength_Description": "Maximum number of characters per message to be Markdown parsed. Messages longer than this will be rendered as plain text. Set to 0 to disable this limit. Warning: High values may significantly impact client-side performance.",
   "Message_not_sent_try_again": "Message not sent. \nPlease try again",
   "Message_QuoteChainLimit": "Maximum Number of Chained Quotes",
   "Message_Read_Receipt_Enabled": "Show Read Receipts",
