Replace plain text emoji at the end of a line

src/components/views/rooms/BasicMessageComposer.tsx

@@ -50,7 +50,8 @@ import { AutocompleteAction, getKeyBindingsManager, MessageComposerAction } from
 import { replaceableComponent } from "../../../utils/replaceableComponent";
 
 // matches emoticons which follow the start of a line or whitespace
-const REGEX_EMOTICON_WHITESPACE = new RegExp('(?:^|\\s)(' + EMOTICON_REGEX.source + ')\\s$');
+const REGEX_EMOTICON_WHITESPACE = new RegExp('(?:^|\\s)(' + EMOTICON_REGEX.source + ')\\s|:^$');
+export const REGEX_EMOTICON = new RegExp('(?:^|\\s)(' + EMOTICON_REGEX.source + ')$');
 
 const IS_MAC = navigator.platform.indexOf("Mac") !== -1;
 
@@ -161,7 +162,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
         }
     }
 
-    private replaceEmoticon = (caretPosition: DocumentPosition): number => {
+    public replaceEmoticon(caretPosition: DocumentPosition, regex: RegExp): number {
         const { model } = this.props;
         const range = model.startRange(caretPosition);
         // expand range max 8 characters backwards from caretPosition,
@@ -170,28 +171,33 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
         range.expandBackwardsWhile((index, offset) => {
             const part = model.parts[index];
             n -= 1;
-            return n >= 0 && (part.type === Type.Plain || part.type === Type.PillCandidate);
+            return n >= 0 && [Type.Plain, Type.PillCandidate, Type.Newline].includes(part.type);
         });
-        const emoticonMatch = REGEX_EMOTICON_WHITESPACE.exec(range.text);
+        const emoticonMatch = regex.exec(range.text);
         if (emoticonMatch) {
             const query = emoticonMatch[1].replace("-", "");
             // try both exact match and lower-case, this means that xd won't match xD but :P will match :p
             const data = EMOTICON_TO_EMOJI.get(query) || EMOTICON_TO_EMOJI.get(query.toLowerCase());
 
             if (data) {
                 const { partCreator } = model;
-                const hasPrecedingSpace = emoticonMatch[0][0] === " ";
+                const moveStart = emoticonMatch[0][0] === " " ? 1 : 0;
+                const moveEnd = emoticonMatch[0].length - emoticonMatch.length - moveStart;
+
                 // we need the range to only comprise of the emoticon
                 // because we'll replace the whole range with an emoji,
                 // so move the start forward to the start of the emoticon.
                 // Take + 1 because index is reported without the possible preceding space.
-                range.moveStart(emoticonMatch.index + (hasPrecedingSpace ? 1 : 0));
+                range.moveStartForwards(emoticonMatch.index + moveStart);
+                // and move end backwards so that we don't replace the trailing space/newline
+                range.moveEndBackwards(moveEnd);
+
                 // this returns the amount of added/removed characters during the replace
                 // so the caret position can be adjusted.
-                return range.replace([partCreator.plain(data.unicode + " ")]);
+                return range.replace([partCreator.plain(data.unicode)]);
             }
         }
-    };
+    }
 
     private updateEditorState = (selection: Caret, inputType?: string, diff?: IDiff): void => {
         renderModel(this.editorRef.current, this.props.model);
@@ -607,8 +613,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     };
 
     private configureEmoticonAutoReplace = (): void => {
-        const shouldReplace = SettingsStore.getValue('MessageComposerInput.autoReplaceEmoji');
-        this.props.model.setTransformCallback(shouldReplace ? this.replaceEmoticon : null);
+        this.props.model.setTransformCallback(this.transform);
     };
 
     private configureShouldShowPillAvatar = (): void => {
@@ -621,6 +626,11 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
         this.setState({ surroundWith });
     };
 
+    private transform = (documentPosition: DocumentPosition): void => {
+        const shouldReplace = SettingsStore.getValue('MessageComposerInput.autoReplaceEmoji');
+        if (shouldReplace) this.replaceEmoticon(documentPosition, REGEX_EMOTICON_WHITESPACE);
+    };
+
     componentWillUnmount() {
         document.removeEventListener("selectionchange", this.onSelectionChange);
         this.editorRef.current.removeEventListener("input", this.onInput, true);

src/components/views/rooms/SendMessageComposer.tsx

@@ -31,8 +31,8 @@ import {
     textSerialize,
     unescapeMessage,
 } from '../../../editor/serialize';
+import BasicMessageComposer, { REGEX_EMOTICON } from "./BasicMessageComposer";
 import { CommandPartCreator, Part, PartCreator, SerializedPart, Type } from '../../../editor/parts';
-import BasicMessageComposer from "./BasicMessageComposer";
 import ReplyThread from "../elements/ReplyThread";
 import { findEditableEvent } from '../../../utils/EventUtils';
 import SendHistoryManager from "../../../SendHistoryManager";
@@ -347,15 +347,24 @@ export default class SendMessageComposer extends React.Component<IProps> {
     }
 
     public async sendMessage(): Promise<void> {
-        if (this.model.isEmpty) {
+        const model = this.model;
+
+        if (model.isEmpty) {
             return;
         }
 
+        // Replace emoticon at the end of the message
+        if (SettingsStore.getValue('MessageComposerInput.autoReplaceEmoji')) {
+            const caret = this.editorRef.current?.getCaret();
+            const position = model.positionForOffset(caret.offset, caret.atNodeEnd);
+            this.editorRef.current?.replaceEmoticon(position, REGEX_EMOTICON);
+        }
+
         const replyToEvent = this.props.replyToEvent;
         let shouldSend = true;
         let content;
 
-        if (!containsEmote(this.model) && this.isSlashCommand()) {
+        if (!containsEmote(model) && this.isSlashCommand()) {
             const [cmd, args, commandText] = this.getSlashCommand();
             if (cmd) {
                 if (cmd.category === CommandCategories.messages) {
@@ -400,7 +409,7 @@ export default class SendMessageComposer extends React.Component<IProps> {
             }
         }
 
-        if (isQuickReaction(this.model)) {
+        if (isQuickReaction(model)) {
             shouldSend = false;
             this.sendQuickReaction();
         }
@@ -410,7 +419,7 @@ export default class SendMessageComposer extends React.Component<IProps> {
             const { roomId } = this.props.room;
             if (!content) {
                 content = createMessageContent(
-                    this.model,
+                    model,
                     replyToEvent,
                     this.props.replyInThread,
                     this.props.permalinkCreator,
@@ -446,9 +455,9 @@ export default class SendMessageComposer extends React.Component<IProps> {
             CountlyAnalytics.instance.trackSendMessage(startTime, prom, roomId, false, !!replyToEvent, content);
         }
 
-        this.sendHistoryManager.save(this.model, replyToEvent);
+        this.sendHistoryManager.save(model, replyToEvent);
         // clear composer
-        this.model.reset([]);
+        model.reset([]);
         this.editorRef.current?.clearUndoHistory();
         this.editorRef.current?.focus();
         this.clearStoredEditorState();

src/editor/range.ts

@@ -32,13 +32,20 @@ export default class Range {
         this._end = bIsLarger ? positionB : positionA;
     }
 
-    public moveStart(delta: number): void {
+    public moveStartForwards(delta: number): void {
         this._start = this._start.forwardsWhile(this.model, () => {
             delta -= 1;
             return delta >= 0;
         });
     }
 
+    public moveEndBackwards(delta: number): void {
+        this._end = this._end.backwardsWhile(this.model, () => {
+            delta -= 1;
+            return delta >= 0;
+        });
+    }
+
     public trim(): void {
         this._start = this._start.forwardsWhile(this.model, whitespacePredicate);
         this._end = this._end.backwardsWhile(this.model, whitespacePredicate);