[NEW] Add reaction to the last message when get the shortcut +:

packages/rocketchat-ui-message/client/popup/messagePopupConfig.html

@@ -2,6 +2,7 @@
 	<div class="message-popup-results">
 		{{#if emojiEnabled}}
 			{{> messagePopup popupEmojiConfig}}
+			{{> messagePopup popupReactionEmojiConfig}}
 		{{/if}}
 		{{> messagePopup popupChannelConfig}}
 		{{> messagePopup popupUserConfig}}

packages/rocketchat-ui-message/client/popup/messagePopupConfig.js

@@ -269,6 +269,47 @@ Template.messagePopupConfig.helpers({
 						return [];
 					}
 
+					const regExp = new RegExp(`^${ RegExp.escape(key) }`, 'i');
+					return Object.keys(collection).map(key => {
+						const value = collection[key];
+						return {
+							_id: key,
+							data: value
+						};
+					})
+						.filter(obj => regExp.test(obj._id))
+						.slice(0, 10)
+						.sort(function(a, b) {
+							if (a._id < b._id) {
+								return -1;
+							}
+							if (a._id > b._id) {
+								return 1;
+							}
+							return 0;
+						});
+				}
+			};
+		}
+	},
+	popupReactionEmojiConfig() {
+		if (RocketChat.emoji != null) {
+			const self = this;
+			return {
+				title: t('Emoji'),
+				collection: RocketChat.emoji.list,
+				template: 'messagePopupEmoji',
+				trigger: '\\+',
+				prefix: '+',
+				suffix: ' ',
+				getInput: self.getInput,
+				getFilter(collection, filter) {
+					const key = `${ filter }`;
+
+					if (!RocketChat.emoji.packages.emojione || RocketChat.emoji.packages.emojione.asciiList[key] || filter.length < 2) {
+						return [];
+					}
+
 					const regExp = new RegExp(`^${ RegExp.escape(key) }`, 'i');
 					return Object.keys(collection).map(key => {
 						const value = collection[key];

packages/rocketchat-ui/client/lib/chatMessages.js

@@ -183,6 +183,16 @@ this.ChatMessages = class ChatMessages {
 			const msg = input.value;
 			const msgObject = { _id: Random.id(), rid, msg};
 
+			if (msg.slice(0, 2) === '+:') {
+				const reaction = msg.slice(1).trim();
+				if (RocketChat.emoji.list[reaction]) {
+					const lastMessage = ChatMessage.findOne({rid}, { fields: { ts: 1 }, sort: { ts: -1 }});
+					Meteor.call('setReaction', reaction, lastMessage._id);
+					input.value = '';
+					return;
+				}
+			}
+
 			// Run to allow local encryption, and maybe other client specific actions to be run before send
 			return RocketChat.promises.run('onClientBeforeSendMessage', msgObject).then(msgObject => {