fix: #7086

public/language/en-GB/error.json

@@ -144,7 +144,7 @@
 	"chat-edit-duration-expired": "You are only allowed to edit chat messages for %1 second(s) after posting",
 	"chat-delete-duration-expired": "You are only allowed to delete chat messages for %1 second(s) after posting",
 	"chat-deleted-already": "This chat message has already been deleted.",
-	"chat-restored'already": "This chat message has already been restored.",
+	"chat-restored-already": "This chat message has already been restored.",
 
 	"already-voting-for-this-post": "You have already voted for this post.",
 	"reputation-system-disabled": "Reputation system is disabled.",

src/messaging/create.js

@@ -36,7 +36,10 @@ module.exports = function (Messaging) {
 				return callback(err);
 			}
 
-			content = String(data.content);
+			content = String(data.content).trim();
+			if (!content) {
+				return callback(new Error('[[error:invalid-chat-message]]'));
+			}
 
 			var maximumChatMessageLength = (meta.config.maximumChatMessageLength || 1000);
 			if (content.length > maximumChatMessageLength) {

src/messaging/edit.js

@@ -19,7 +19,9 @@ module.exports = function (Messaging) {
 				if (raw === content) {
 					return callback();
 				}
-
+				if (!String(content).trim()) {
+					return callback(new Error('[[error:invalid-chat-message]]'));
+				}
 				Messaging.setMessageFields(mid, {
 					content: content,
 					edited: Date.now(),

test/messaging.js

@@ -276,6 +276,13 @@ describe('Messaging Library', function () {
 			});
 		});
 
+		it('should fail to send chat if content is empty', function (done) {
+			socketModules.chats.send({ uid: fooUid }, { roomId: roomId, message: ' ' }, function (err) {
+				assert.equal(err.message, '[[error:invalid-chat-message]]');
+				done();
+			});
+		});
+
 		it('should send a message to a room', function (done) {
 			socketModules.chats.send({ uid: fooUid }, { roomId: roomId, message: 'first chat message' }, function (err, messageData) {
 				assert.ifError(err);
@@ -554,6 +561,13 @@ describe('Messaging Library', function () {
 			});
 		});
 
+		it('should fail to edit message if new content is empty string', function (done) {
+			socketModules.chats.edit({ uid: fooUid }, { mid: 5, roomId: roomId, message: ' ' }, function (err) {
+				assert.equal(err.message, '[[error:invalid-chat-message]]');
+				done();
+			});
+		});
+
 		it('should fail to edit message if not own message', function (done) {
 			socketModules.chats.edit({ uid: herpUid }, { mid: 5, roomId: roomId, message: 'message edited' }, function (err) {
 				assert.equal(err.message, '[[error:cant-edit-chat-message]]');