fix(MessagesList): restore the state if context request was canceled,…

… abort lookForNewMessages request if query param is missing

Signed-off-by: Maksim Sukharev <antreesy.web@gmail.com>

src/components/MessagesList/MessagesList.vue

@@ -643,7 +643,14 @@ export default {
 					this.$store.dispatch('setLastKnownMessageId', { token, id: startingMessageId })
 
 					// Get chat messages before last read message and after it
-					await this.getMessageContext(token, startingMessageId)
+					try {
+						await this.getMessageContext(token, startingMessageId)
+					} catch (exception) {
+						// Request was cancelled, stop getting preconditions and restore initial state
+						this.$store.dispatch('setFirstKnownMessageId', { token, id: null })
+						this.$store.dispatch('setLastKnownMessageId', { token, id: null })
+						return
+					}
 				}
 
 				this.$nextTick(() => {
@@ -686,9 +693,12 @@ export default {
 					messageId,
 					minimumVisible: CHAT.MINIMUM_VISIBLE,
 				})
+				this.loadingOldMessages = false
 			} catch (exception) {
 				if (Axios.isCancel(exception)) {
 					console.debug('The request has been canceled', exception)
+					this.loadingOldMessages = false
+					throw exception
 				}
 
 				if (exception?.response?.status === 304 && exception?.response?.data === '') {

src/store/messagesStore.js

@@ -1110,6 +1110,12 @@ const actions = {
 	async lookForNewMessages(context, { token, lastKnownMessageId, requestId, requestOptions }) {
 		context.dispatch('cancelLookForNewMessages', { requestId })
 
+		if (!lastKnownMessageId) {
+			// if param is null | undefined, it won't be included in the request query
+			console.warn('Trying to load messages without the required parameter')
+			return
+		}
+
 		// Get a new cancelable request function and cancel function pair
 		const { request, cancel } = CancelableRequest(lookForNewMessages)
 

src/store/messagesStore.spec.js

@@ -1300,6 +1300,10 @@ describe('messagesStore', () => {
 			store = new Vuex.Store(testStoreConfig)
 		})
 
+		afterEach(() => {
+			jest.clearAllMocks()
+		})
+
 		test('looks for new messages', async () => {
 			const messages = [{
 				id: 1,
@@ -1389,6 +1393,25 @@ describe('messagesStore', () => {
 			expect(store.getters.getLastKnownMessageId(TOKEN)).toBe(null)
 		})
 
+		test('does not look for new messages if lastKnownMessageId is falsy', async () => {
+			// Arrange: prepare cancelable request from previous call of the function
+			const cancelFunctionMock = jest.fn()
+			cancelFunctionMocks.push(cancelFunctionMock)
+			store.commit('setCancelLookForNewMessages', { cancelFunction: cancelFunctionMock, requestId: 'request1' })
+			console.warn = jest.fn()
+
+			// Act
+			store.dispatch('lookForNewMessages', {
+				token: TOKEN,
+				requestId: 'request1',
+				lastKnownMessageId: null,
+			})
+
+			// Assert
+			expect(cancelFunctionMocks[0]).toHaveBeenCalledWith('canceled')
+			expect(lookForNewMessages).not.toHaveBeenCalled()
+		})
+
 		test('cancels look for new messages', async () => {
 			store.dispatch('lookForNewMessages', {
 				token: TOKEN,