Chat message soft deletion -- closes #6181

Squashed commit of the following:

commit f84c06bdcc45f24ef7ffde6a8f33b48d8f97fc36
Author: Julian Lam <julian@nodebb.org>
Date:   Mon Dec 18 14:42:47 2017 -0500

    added restore handler for chat messages

commit 725cd370c6ea1e8f4a28298350f3dc024d4e668e
Author: Julian Lam <julian@nodebb.org>
Date:   Mon Dec 18 14:23:52 2017 -0500

    backend logic and testing complete for deletion and restoration of chat messages

commit 072da758319cc93fa4c6f8bc0d672a1b716dc06e
Author: Julian Lam <julian@nodebb.org>
Date:   Mon Dec 18 13:52:35 2017 -0500

    changing message delete logic to not remove mids, but to filter when retrieving

commit 68bf373305ab82737658a7c31dc5549af4d6d69f
Author: Julian Lam <julian@nodebb.org>
Date:   Mon Dec 18 12:37:58 2017 -0500

    logic to handle deletion of a deleted chat message -- added some failing tests

commit 6899d0d234fa752e227188aa69cfcabd0d0500cc
Author: Julian Lam <julian@nodebb.org>
Date:   Mon Dec 18 11:35:36 2017 -0500

    chat message deletion logic

public/language/en-GB/error.json

@@ -140,6 +140,8 @@
 	"cant-delete-chat-message": "You are not allowed to delete this message",
 	"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.",
 
 	"already-voting-for-this-post": "You have already voted for this post.",
 	"reputation-system-disabled": "Reputation system is disabled.",

public/src/client/chats.js

@@ -71,7 +71,7 @@ define('forum/chats', [
 			});
 		});
 
-		Chats.addEditDeleteHandler(components.get('chat/messages'), ajaxify.data.roomId);
+		Chats.addActionHandlers(components.get('chat/messages'), ajaxify.data.roomId);
 
 		Chats.addRenameHandler(ajaxify.data.roomId, $('[component="chat/room/name"]'));
 		Chats.addScrollHandler(ajaxify.data.roomId, ajaxify.data.uid, $('.chat-content'));
@@ -123,14 +123,25 @@ define('forum/chats', [
 		});
 	};
 
-	Chats.addEditDeleteHandler = function (element, roomId) {
+	Chats.addActionHandlers = function (element, roomId) {
-		element.on('click', '[data-action="edit"]', function () {
+		element.on('click', '[data-action]', function () {
 			var messageId = $(this).parents('[data-mid]').attr('data-mid');
+			var action = this.getAttribute('data-action');
+
+			switch (action) {
+			case 'edit':
 				var inputEl = $('[data-roomid="' + roomId + '"] [component="chat/input"]');
 				messages.prepEdit(inputEl, messageId, roomId);
-		}).on('click', '[data-action="delete"]', function () {
+				break;
-			var messageId = $(this).parents('[data-mid]').attr('data-mid');
+
+			case 'delete':
 				messages.delete(messageId, roomId);
+				break;
+
+			case 'restore':
+				messages.restore(messageId, roomId);
+				break;
+			}
 		});
 	};
 

public/src/client/chats/messages.js

@@ -146,13 +146,24 @@ define('forum/chats/messages', ['components', 'sounds', 'translator', 'benchpres
 						return app.alertError(err.message);
 					}
 
-					components.get('chat/message', messageId).slideUp('slow', function () {
+					components.get('chat/message', messageId).toggleClass('deleted', true);
-						$(this).remove();
-					});
 				});
 			});
 		});
 	};
 
+	messages.restore = function (messageId, roomId) {
+		socket.emit('modules.chats.restore', {
+			messageId: messageId,
+			roomId: roomId,
+		}, function (err) {
+			if (err) {
+				return app.alertError(err.message);
+			}
+
+			components.get('chat/message', messageId).toggleClass('deleted', false);
+		});
+	};
+
 	return messages;
 });

src/messaging.js

@@ -56,6 +56,16 @@ Messaging.getMessages = function (params, callback) {
 			messageData.forEach(function (messageData) {
 				messageData.index = indices[messageData.messageId.toString()];
 			});
+
+			// Filter out deleted messages unless you're the sender of said message
+			messageData = messageData.filter(function (messageData) {
+				if (messageData.deleted && parseInt(messageData.fromuid, 10) !== parseInt(params.uid, 10)) {
+					return false;
+				}
+
+				return true;
+			});
+
 			next(null, messageData);
 		},
 	], callback);

src/messaging/create.js

@@ -58,6 +58,7 @@ module.exports = function (Messaging) {
 					timestamp: timestamp,
 					fromuid: fromuid,
 					roomId: roomId,
+					deleted: 0,
 				};
 
 				plugins.fireHook('filter:messaging.save', message, next);

src/messaging/data.js

@@ -67,6 +67,8 @@ module.exports = function (Messaging) {
 					if (message.hasOwnProperty('edited')) {
 						message.editedISO = new Date(parseInt(message.edited, 10)).toISOString();
 					}
+
+					message.deleted = !!parseInt(message.deleted, 10);
 				});
 
 				async.map(messages, function (message, next) {

src/messaging/delete.js

@@ -1,25 +1,30 @@
 'use strict';
 
 var async = require('async');
-var db = require('../database');
 
 module.exports = function (Messaging) {
 	Messaging.deleteMessage = function (mid, roomId, callback) {
 		async.waterfall([
-			function (next) {
+			async.apply(Messaging.getMessageField, mid, 'deleted'),
-				Messaging.getUidsInRoom(roomId, 0, -1, next);
+			function (deleted, next) {
-			},
+				if (parseInt(deleted, 10)) {
-			function (uids, next) {
+					return next(new Error('[[error:chat-deleted-already]]'));
-				if (!uids.length) {
-					return next();
 				}
-				var keys = uids.map(function (uid) {
+
-					return 'uid:' + uid + ':chat:room:' + roomId + ':mids';
+				Messaging.setMessageField(mid, 'deleted', 1, next);
-				});
-				db.sortedSetsRemove(keys, mid, next);
 			},
-			function (next) {
+		], callback);
-				db.delete('message:' + mid, next);
+	};
+
+	Messaging.restoreMessage = function (mid, roomId, callback) {
+		async.waterfall([
+			async.apply(Messaging.getMessageField, mid, 'deleted'),
+			function (deleted, next) {
+				if (!parseInt(deleted, 10)) {
+					return next(new Error('[[error:chat-restored-already]]'));
+				}
+
+				Messaging.setMessageField(mid, 'deleted', 0, next);
 			},
 		], callback);
 	};

src/socket.io/modules.js

@@ -267,6 +267,21 @@ SocketModules.chats.delete = function (socket, data, callback) {
 	], callback);
 };
 
+SocketModules.chats.restore = function (socket, data, callback) {
+	if (!data || !data.roomId || !data.messageId) {
+		return callback(new Error('[[error:invalid-data]]'));
+	}
+
+	async.waterfall([
+		function (next) {
+			Messaging.canDelete(data.messageId, socket.uid, next);
+		},
+		function (next) {
+			Messaging.restoreMessage(data.messageId, data.roomId, next);
+		},
+	], callback);
+};
+
 SocketModules.chats.canMessage = function (socket, roomId, callback) {
 	Messaging.canMessageRoom(socket.uid, roomId, callback);
 };

test/messaging.js

@@ -14,8 +14,8 @@ var helpers = require('./helpers');
 var socketModules = require('../src/socket.io/modules');
 
 describe('Messaging Library', function () {
-	var fooUid;
+	var fooUid;	// the admin
-	var bazUid;
+	var bazUid;	// the user with chat restriction enabled
 	var herpUid;
 	var roomId;
 
@@ -552,20 +552,70 @@ describe('Messaging Library', function () {
 			});
 		});
 
-
+		it('should mark the message as deleted', function (done) {
-		it('should delete message', function (done) {
 			socketModules.chats.delete({ uid: fooUid }, { messageId: mid, roomId: roomId }, function (err) {
 				assert.ifError(err);
-				db.exists('message:' + mid, function (err, exists) {
+				db.getObjectField('message:' + mid, 'deleted', function (err, value) {
 					assert.ifError(err);
-					assert(!exists);
+					assert.strictEqual(1, parseInt(value, 10));
-					db.isSortedSetMember('uid:' + fooUid + ':chat:room:' + roomId + ':mids', mid, function (err, isMember) {
-						assert.ifError(err);
-						assert(!isMember);
 					done();
 				});
 			});
 		});
+
+		it('should show deleted message to original users', function (done) {
+			socketModules.chats.getMessages({ uid: fooUid }, { uid: fooUid, roomId: roomId, start: 0 }, function (err, messages) {
+				assert.ifError(err);
+
+				// Reduce messages to their mids
+				var mids = messages.reduce(function (mids, cur) {
+					mids.push(cur.messageId);
+					return mids;
+				}, []);
+
+				assert(mids.includes(mid));
+				done();
+			});
+		});
+
+		it('should not show deleted message to other users', function (done) {
+			socketModules.chats.getMessages({ uid: herpUid }, { uid: herpUid, roomId: roomId, start: 0 }, function (err, messages) {
+				assert.ifError(err);
+
+				// Reduce messages to their mids
+				var mids = messages.reduce(function (mids, cur) {
+					mids.push(cur.messageId);
+					return mids;
+				}, []);
+
+				assert(!mids.includes(mid));
+				done();
+			});
+		});
+
+		it('should error out if a message is deleted again', function (done) {
+			socketModules.chats.delete({ uid: fooUid }, { messageId: mid, roomId: roomId }, function (err) {
+				assert.strictEqual('[[error:chat-deleted-already]]', err.message);
+				done();
+			});
+		});
+
+		it('should restore the message', function (done) {
+			socketModules.chats.restore({ uid: fooUid }, { messageId: mid, roomId: roomId }, function (err) {
+				assert.ifError(err);
+				db.getObjectField('message:' + mid, 'deleted', function (err, value) {
+					assert.ifError(err);
+					assert.strictEqual(0, parseInt(value, 10));
+					done();
+				});
+			});
+		});
+
+		it('should error out if a message is restored again', function (done) {
+			socketModules.chats.restore({ uid: fooUid }, { messageId: mid, roomId: roomId }, function (err) {
+				assert.strictEqual('[[error:chat-restored-already]]', err.message);
+				done();
+			});
 		});
 	});