fixup! Fix(MessagesList): skip soft update when needed and make editi…

…ng a message softer

src/components/MessagesList/MessagesList.vue

@@ -140,7 +140,7 @@ export default {
 	data() {
 		return {
 			/**
-			 * An array of messages grouped in nested arrays by same day and then by author.
+			 * A list of messages grouped by same day and then by author and time.
 			 */
 
 			messagesGroupedByDateByAuthor: {},
@@ -365,7 +365,7 @@ export default {
 
 	methods: {
 		prepareMessagesGroups(messages) {
-			let prevGroupMap = {}
+			let prevGroupMap = null
 			const groupsByDate = {}
 			let lastMessage = null
 			let groupId = null
@@ -393,15 +393,13 @@ export default {
 						messages: [message],
 						token: this.token,
 						dateTimestamp,
-						previousMessageId: Object.keys(prevGroupMap).length
-							? groupsByDate[prevGroupMap.date][prevGroupMap.groupId].messages.at(-1).id
-							: 0,
+						previousMessageId: lastMessage?.id || 0,
 						nextMessageId: 0,
 						isSystemMessagesGroup: message.systemMessage.length !== 0,
 					}
 
 					// Update the previous group with the next message id
-					if (Object.keys(prevGroupMap).length) {
+					if (prevGroupMap) {
 						groupsByDate[prevGroupMap.date][prevGroupMap.groupId].nextMessageId = message.id
 					}
 
@@ -437,7 +435,7 @@ export default {
 			const oldGroupsMap = new Map(Object.entries(oldGroups))
 			Object.entries(newGroups).forEach(([id, newGroup]) => {
 				if (!oldGroupsMap.has(id) || (oldGroupsMap.has(id) && !this.areGroupsIdentical(newGroup, oldGroupsMap.get(id)))) {
-					this.messagesGroupedByDateByAuthor[newGroup.dateTimestamp][id] = newGroup
+					this.messagesGroupedByDateByAuthor[dateTimestamp][id] = newGroup
 				}
 			})
 
@@ -449,7 +447,7 @@ export default {
 						break
 					}
 					if (!newGroupsMap.has(id)) {
-						delete this.messagesGroupedByDateByAuthor[oldGroup.dateTimestamp][id]
+						delete this.messagesGroupedByDateByAuthor[dateTimestamp][id]
 					}
 				}
 			}
@@ -736,24 +734,30 @@ export default {
 				return
 			}
 			// find the corresponding messages group in the list
-			const group = Object.values(groups).find(group => group.id <= message.id && (group.nextMessageId >= message.id || group.nextMessageId === 0))
+			const group = Object.values(groups).find(group => group.id <= message.id && (group.nextMessageId > message.id || group.nextMessageId === 0))
 
 			if (!group) {
 				// Messages were not loaded yet
 				return
 			}
+
+			if (group.messages.length === 1 && group.id === message.id) {
+				// Nothing to split
+				this.messagesGroupedByDateByAuthor[dateGroupId][group.id].messages = [message]
+				return
+			}
+
 			// we split the group in 3 part,
 			// 1. the messages before the edited message (if any)
 			// 2. the edited message
 			// 3. the messages after the edited message (if any)
-			let nextMessageId = 0
+			const nextMessageId = group.nextMessageId
 			const index = group.messages.findIndex(m => m.id === message.id)
 			const before = group.messages.slice(0, index)
 			const after = group.messages.slice(index + 1)
 			// If there are before messages, we keep them in the same group
 			if (before.length) {
 				this.messagesGroupedByDateByAuthor[dateGroupId][group.id].messages = before
-				nextMessageId = group.nextMessageId
 				this.messagesGroupedByDateByAuthor[dateGroupId][group.id].nextMessageId = message.id
 			}
 			// We create a new group for the edited message
@@ -778,7 +782,6 @@ export default {
 					nextMessageId,
 					isSystemMessagesGroup: message.systemMessage.length !== 0,
 				}
-				this.messagesGroupedByDateByAuthor[dateGroupId][message.id].nextMessageId = newGroupId
 			}
 		},