feat: add highlight words feature for messages and user preferences

app/containers/markdown/HighlightWords.stories.tsx

@@ -0,0 +1,37 @@
+
+import React from 'react';
+import { View, StyleSheet } from 'react-native';
+import { NavigationContainer } from '@react-navigation/native';
+
+import Markdown from '.';
+import { themes } from '../../lib/constants/colors';
+
+const theme = 'light';
+
+const styles = StyleSheet.create({
+	container: {
+		marginHorizontal: 15,
+		backgroundColor: themes[theme].surfaceRoom,
+		marginVertical: 50
+	}
+});
+
+export default {
+	title: 'Markdown/Highlights',
+	decorators: [
+		(Story: any) => (
+			<NavigationContainer>
+				<Story />
+			</NavigationContainer>
+		)
+	]
+};
+
+export const Highlights = () => (
+	<View style={styles.container}>
+		<Markdown highlights={['rocket', 'Lorem', 'mixed']} msg={'This is Rocket.Chat — highlight the word rocket (case-insensitive).'} />
+		<Markdown highlights={['rocket', 'Lorem', 'mixed']} msg={'Lorem ipsum dolor sit amet, this should highlight Lorem and mixed-case Mixed.'} />
+		<Markdown highlights={['rocket', 'Lorem', 'mixed']} msg={'Edge cases: rockets, rocketing (only exact words defined will match).'} />
+	</View>
+);
+

app/containers/markdown/components/Plain.test.tsx

@@ -0,0 +1,109 @@
+import React from 'react';
+import { render } from '@testing-library/react-native';
+
+import { ThemeContext } from '../../../theme';
+import { colors as themeColors } from '../../../lib/constants/colors';
+import MarkdownContext from '../contexts/MarkdownContext';
+import Plain from './Plain';
+
+describe('Plain (highlights)', () => {
+  const colors = themeColors.light;
+
+  const getBackground = (node: any) => {
+    const { style } = node.props;
+    return Array.isArray(style) ? style.find((s: any) => s && s.backgroundColor)?.backgroundColor : style?.backgroundColor;
+  };
+
+  it('renders highlighted words with theme highlight background', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: ['rocket'] }}>
+          <Plain value={'hello rocket world'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    const highlighted = tree.getByText('rocket');
+    expect(highlighted).toBeTruthy();
+    expect(getBackground(highlighted)).toBe(colors.statusBackgroundDanger);
+  });
+
+  it('is case-insensitive when matching highlight words', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: ['Rocket'] }}>
+          <Plain value={'hello rocket world'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    const highlighted = tree.getByText('rocket');
+    expect(highlighted).toBeTruthy();
+    expect(getBackground(highlighted)).toBe(colors.statusBackgroundDanger);
+  });
+
+  it('handles punctuation after words', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: ['rocket'] }}>
+          <Plain value={'hello rocket, world!'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    const highlighted = tree.getByText('rocket');
+    expect(highlighted).toBeTruthy();
+    expect(getBackground(highlighted)).toBe(colors.statusBackgroundDanger);
+  });
+
+  it('renders multiple highlights', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: ['rocket', 'world'] }}>
+          <Plain value={'hello rocket world'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    const h1 = tree.getByText('rocket');
+    const h2 = tree.getByText('world');
+    expect(h1).toBeTruthy();
+    expect(h2).toBeTruthy();
+    expect(getBackground(h1)).toBe(colors.statusBackgroundDanger);
+    expect(getBackground(h2)).toBe(colors.statusBackgroundDanger);
+  });
+
+  it('does not highlight partial words', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: ['rocket'] }}>
+          <Plain value={'hello rockets and rocketing world'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    // there should be no separate node with text 'rocket' (partial matches shouldn't count)
+    const rocket = tree.queryByText('rocket');
+    expect(rocket).toBeNull();
+
+    // full text should still be rendered
+    const full = tree.getByText('hello rockets and rocketing world');
+    expect(full).toBeTruthy();
+  });
+
+  it('when no highlights configured returns full text and does not create separate highlighted nodes', () => {
+    const tree = render(
+      <ThemeContext.Provider value={{ theme: 'light', colors }}>
+        <MarkdownContext.Provider value={{ highlights: [] }}>
+          <Plain value={'hello rocket world'} />
+        </MarkdownContext.Provider>
+      </ThemeContext.Provider>
+    );
+
+    const full = tree.getByText('hello rocket world');
+    expect(full).toBeTruthy();
+    // there should be no separate node with text 'rocket'
+    const rocket = tree.queryByText('rocket');
+    expect(rocket).toBeNull();
+  });
+});

app/containers/markdown/components/Plain.tsx

@@ -10,12 +10,69 @@ interface IPlainProps {
 	value: PlainProps['value'];
 }
 
+const escapeRegExp = (s: string) => s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+
 const Plain = ({ value }: IPlainProps): React.ReactElement => {
 	const { colors } = useTheme();
-	const { textStyle } = useContext(MarkdownContext);
+	const { highlights = [] } = useContext<any>(MarkdownContext);
+
+	const text = (value ?? '').toString();
+
+	if (!highlights || !highlights.length) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+
+	// prepare case-insensitive set of highlight words
+	const words = highlights.map((w: any) => w?.toString().trim()).filter(Boolean);
+	if (!words.length) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+
+	const wordsLower = new Set(words.map((w: string) => w.toLowerCase()));
+	// build regex to split and keep matched parts; guard pattern
+	// build alternation pattern from escaped words; word-boundaries are applied
+	// around the full pattern when constructing the RegExp below to avoid
+	// duplicating boundary anchors per item.
+	const pattern = words.map((w: string) => escapeRegExp(w)).filter(Boolean).join('|');
+	if (!pattern) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+	// ensure the overall pattern is anchored to word boundaries so only whole words match
+	// use a non-capturing group for the alternation to avoid nested captured groups
+	// which would cause duplicate entries when splitting.
+	const re = new RegExp(`(\\b(?:${pattern})\\b)`, 'ig');
+	const parts = text.split(re);
+
+	// use red highlight for matched words (theme-aware tokens)
+	const bg = colors.statusBackgroundDanger ?? '#FFC1C9';
+	const matchTextColor = colors.statusFontDanger ?? colors.fontDefault;
+
 	return (
-		<Text accessibilityLabel={value} style={[styles.plainText, { color: colors.fontDefault }, ...(textStyle ? [textStyle] : [])]}>
-			{value}
+		<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}> 
+			{parts.map((part, i) => {
+				if (!part) return null;
+				const isMatch = wordsLower.has(part.toLowerCase());
+				if (isMatch) {
+					return (
+						<Text key={`h-${i}`} style={{ backgroundColor: bg, color: matchTextColor }}>
+							{part}
+						</Text>
+					);
+				}
+				return <Text key={`p-${i}`}>{part}</Text>;
+			})}
 		</Text>
 	);
 };

app/containers/markdown/contexts/MarkdownContext.ts

@@ -11,16 +11,17 @@ interface IMarkdownContext {
 	navToRoomInfo?: Function;
 	getCustomEmoji?: Function;
 	onLinkPress?: Function;
-	textStyle?: StyleProp<TextStyle>;
+	highlights?: string[];
 }
 
 const defaultState = {
 	mentions: [],
 	channels: [],
 	useRealName: false,
 	username: '',
-	navToRoomInfo: () => {},
-	textStyle: undefined
+	navToRoomInfo: () => {}
+	,
+	highlights: []
 };
 
 const MarkdownContext = React.createContext<IMarkdownContext>(defaultState);

app/containers/markdown/index.tsx

@@ -32,7 +32,7 @@ interface IMarkdownProps {
 	navToRoomInfo?: Function;
 	onLinkPress?: TOnLinkPress;
 	isTranslated?: boolean;
-	textStyle?: StyleProp<TextStyle>;
+	highlights?: string[];
 }
 
 const Markdown: React.FC<IMarkdownProps> = ({
@@ -46,7 +46,7 @@ const Markdown: React.FC<IMarkdownProps> = ({
 	getCustomEmoji,
 	onLinkPress,
 	isTranslated,
-	textStyle
+	highlights = []
 }: IMarkdownProps) => {
 	if (!msg) return null;
 
@@ -70,7 +70,7 @@ const Markdown: React.FC<IMarkdownProps> = ({
 					navToRoomInfo,
 					getCustomEmoji,
 					onLinkPress,
-					textStyle
+					highlights
 				}}>
 				{tokens?.map(block => {
 					switch (block.type) {

app/containers/message/Content.tsx

@@ -67,6 +67,7 @@ const Content = React.memo(
 					useRealName={props.useRealName}
 					onLinkPress={onLinkPress}
 					isTranslated={props.isTranslated}
+					highlights={props.highlights}
 				/>
 			);
 		}

app/containers/message/index.tsx

@@ -63,6 +63,7 @@ interface IMessageContainerProps {
 	isPreview?: boolean;
 	dateSeparator?: Date | string | null;
 	showUnreadSeparator?: boolean;
+	highlights?: string[];
 }
 
 interface IMessageContainerState {
@@ -375,11 +376,12 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 			threadBadgeColor,
 			toggleFollowThread,
 			jumpToMessage,
-			highlighted,
+			highlighted: propHighlighted,
 			isBeingEdited,
 			isPreview,
 			showUnreadSeparator,
-			dateSeparator
+			dateSeparator,
+			highlights
 		} = this.props;
 		const {
 			id,
@@ -426,6 +428,10 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 
 		const canTranslateMessage = autoTranslateRoom && autoTranslateLanguage && autoTranslateMessage !== false && otherUserMessage;
 
+		const safeMessage = (message ?? '').toString();
+		const isHighlighted =
+			propHighlighted || (highlights && highlights.some(word => safeMessage.toLowerCase().includes(word.toLowerCase())));
+
 		return (
 			<MessageContext.Provider
 				value={{
@@ -499,7 +505,8 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 					navToRoomInfo={navToRoomInfo}
 					handleEnterCall={handleEnterCall}
 					blockAction={blockAction}
-					highlighted={highlighted}
+					highlighted={isHighlighted}
+					highlights={highlights}
 					comment={comment}
 					isTranslated={isTranslated}
 					isBeingEdited={isBeingEdited}

app/containers/message/interfaces.ts

@@ -70,6 +70,7 @@ export interface IMessageContent {
 	hasError: boolean;
 	isHeader: boolean;
 	isTranslated: boolean;
+	highlights?: string[];
 	pinned?: boolean;
 }
 

app/definitions/IUser.ts

@@ -99,9 +99,9 @@ export interface IUserEmail {
 
 export interface IUserSettings {
 	profile?: any;
-	preferences: {
-		[key: string]: any;
-	};
+	// preferences should follow the structured notification and message preferences
+	// which include `highlights` and other typed keys
+	preferences: INotificationPreferences & IMessagePreferences;
 }
 export type TNotifications = 'default' | 'all' | 'mentions' | 'nothing';
 
@@ -112,6 +112,7 @@ export interface INotificationPreferences {
 	pushNotifications: TNotifications;
 	emailNotificationMode: 'mentions' | 'nothing';
 	language?: string;
+	highlights?: string[];
 }
 
 export interface IMessagePreferences {

app/i18n/locales/en.json

@@ -404,6 +404,12 @@
   "Hide_room": "Hide",
   "Hide_System_Messages": "Hide system messages",
   "Hide_type_messages": "Hide \"{{type}}\" messages",
+  "Highlight_Words": "Highlight words",
+  "Highlight_Words_Description": "Words to highlight in messages, separated by commas",
+  "Highlights": "Highlights",
+  "Highlights_Description": "Words to highlight in messages, separated by commas",
+  "Highlights_save_failed": "Failed to save highlights",
+  "Highlights_saved_successfully": "Highlights saved successfully",
   "How_It_Works": "How it works",
   "I_Saved_My_E2E_Password": "I saved my E2E password",
   "Ignore": "Ignore",

app/views/RoomView/index.tsx

@@ -1475,6 +1475,7 @@ class RoomView extends React.Component<IRoomViewProps, IRoomViewState> {
 					isBeingEdited={isBeingEdited}
 					dateSeparator={dateSeparator}
 					showUnreadSeparator={showUnreadSeparator}
+					highlights={user.settings?.preferences?.highlights}
 				/>
 			);
 		}