[FIX] Bad words falling if message is empty (#22930)

Co-authored-by: Diego Sampaio <chinello@gmail.com>

app/lib/server/methods/filterBadWords.ts

@@ -0,0 +1,56 @@
+import { Meteor } from 'meteor/meteor';
+import { Tracker } from 'meteor/tracker';
+import Filter from 'bad-words';
+
+import { settings } from '../../../settings/server';
+import { callbacks } from '../../../callbacks/server';
+import { IMessage } from '../../../../definition/IMessage';
+
+const Dep = new Tracker.Dependency();
+Meteor.startup(() => {
+	settings.get(/Message_AllowBadWordsFilter|Message_BadWordsFilterList|Message_BadWordsWhitelist/, () => {
+		Dep.changed();
+	});
+	Tracker.autorun(() => {
+		Dep.depend();
+		const allowBadWordsFilter = settings.get('Message_AllowBadWordsFilter');
+
+		callbacks.remove('beforeSaveMessage', 'filterBadWords');
+
+		if (!allowBadWordsFilter) {
+			return;
+		}
+
+		const badWordsList = settings.get('Message_BadWordsFilterList') as string | undefined;
+		const whiteList = settings.get('Message_BadWordsWhitelist') as string | undefined;
+
+		const options = {
+			list: badWordsList?.split(',').map((word) => word.trim()).filter(Boolean) || [],
+			// library definition does not allow optional definition
+			exclude: undefined,
+			splitRegex: undefined,
+			placeHolder: undefined,
+			regex: undefined,
+			replaceRegex: undefined,
+			emptyList: undefined,
+		};
+
+		const filter = new Filter(options);
+
+		if (whiteList?.length) {
+			filter.removeWords(...whiteList.split(',').map((word) => word.trim()));
+		}
+
+		callbacks.add('beforeSaveMessage', function(message: IMessage) {
+			if (!message.msg) {
+				return message;
+			}
+			try {
+				message.msg = filter.clean(message.msg);
+			} finally {
+				// eslint-disable-next-line no-unsafe-finally
+				return message;
+			}
+		}, callbacks.priority.HIGH, 'filterBadWords');
+	});
+});

package.json

@@ -60,6 +60,7 @@
 		"@storybook/addons": "^6.3.6",
 		"@storybook/react": "^6.3.6",
 		"@types/agenda": "^2.0.9",
+		"@types/bad-words": "^3.0.1",
 		"@types/bcrypt": "^5.0.0",
 		"@types/body-parser": "^1.19.0",
 		"@types/chai": "^4.2.19",