feat: harden support, localize knowledge and add operator availability [skip ci]

Source-only publication of reviewed commit 64e96a7f423673dc29ad56485be9fc79bce8af1c.

Passed in isolation: focused frontend/backend tests, race checks, TypeScript typecheck, lint, Go compilation, Flowgram build, and deterministic SDK build/tests.

Not accepted as a production release: Next.js export/native assembly remains blocked by environment memory limits; browser interaction and MySQL staging acceptance remain unverified. No production server, database/schema, runtime configuration, deployment, release tag, or workflow execution was performed.

Expected source tree: 0a4a7528e9.

web/lib/stores/agent-conversations.test.mjs

@@ -0,0 +1,127 @@
+import assert from "node:assert/strict"
+import test from "node:test"
+import { deferred, loadTypeScriptModule } from "../test-support/load-typescript-module.mjs"
+
+function createStore(initialize) {
+  let state
+  const setState = (update, replace = false) => {
+    const next = typeof update === "function" ? update(state) : update
+    state = replace ? next : { ...state, ...next }
+  }
+  state = initialize(setState, () => state)
+  const initial = state
+  return { getState: () => state, setState, getInitialState: () => initial }
+}
+
+function fixture(api = {}) {
+  let session = { user: { id: 1 }, accessToken: "test-session-a" }
+  const loaded = loadTypeScriptModule(new URL("./agent-conversations.ts", import.meta.url), {
+    zustand: { create: createStore },
+    "@/lib/api/agent": api,
+    "@/lib/auth": { readSession: () => session },
+    "@/lib/utils": { generateUUID: () => "test-id" },
+    "@/lib/im-message": { summarizeIMMessage: () => "test-summary" },
+    "@/lib/im-message-merge": {
+      cursorFromLoadedImMessages: (messages) => String(messages[0]?.id ?? ""),
+      hasMoreAfterLatestImMessageMerge: () => false,
+      mergeImMessagesByIdAsc: (left, right) => [...left, ...right],
+      parseImMessageCursorId: Number,
+    },
+    "@/lib/im-realtime-state": {
+      patchConversationList: (list) => list,
+      patchConversationListWithMessage: (list) => list,
+    },
+    "@/lib/agent-activity-state": {},
+    "@/lib/operator-presence-state": {},
+  })
+  return {
+    store: loaded.useAgentConversationsStore,
+    reset: loaded.resetAgentConversations,
+    set session(next) { session = next },
+  }
+}
+
+test("late conversation list cannot restore private data after reset/account change", async () => {
+  const old = deferred()
+  const f = fixture({ fetchAgentConversations: () => old.promise })
+  const loading = f.store.getState().loadConversations()
+  f.session = { user: { id: 2 }, accessToken: "test-session-b" }
+  f.reset()
+  f.store.setState({ conversations: [{ id: 20 }], selectedConversationId: 20 })
+  old.resolve({ results: [{ id: 10 }] })
+  await loading
+  assert.equal(f.store.getState().conversations[0].id, 20)
+  assert.equal(f.store.getState().selectedConversationId, 20)
+})
+
+test("same-account relogin invalidates old load generations too", async () => {
+  const old = deferred()
+  const f = fixture({ fetchAgentMessages: () => old.promise })
+  f.store.setState({ selectedConversationId: 10 })
+  const loading = f.store.getState().loadMessages(10)
+  f.reset()
+  f.store.setState({ selectedConversationId: 10, messages: [{ id: 200 }] })
+  old.resolve({ results: [{ id: 100 }] })
+  await loading
+  assert.equal(f.store.getState().messages[0].id, 200)
+})
+
+test("operator send binds its recipient, is single-flight, and does not patch the new selection", async () => {
+  const response = deferred()
+  const calls = []
+  const f = fixture({ sendAgentMessage: (payload) => { calls.push(payload); return response.promise } })
+  f.store.setState({ selectedConversationId: 10 })
+  assert.equal(await f.store.getState().sendMessage("Wrong recipient", 20), null)
+  const sending = f.store.getState().sendMessage("For A", 10)
+  assert.equal(await f.store.getState().sendMessage("Duplicate", 10), null)
+  f.store.setState({ selectedConversationId: 20, messages: [{ id: 200 }] })
+  response.resolve({ id: 100, conversationId: 10 })
+  await sending
+  assert.equal(calls.length, 1)
+  assert.equal(calls[0].conversationId, 10)
+  assert.equal(f.store.getState().messages[0].id, 200)
+})
+
+test("old send finally does not unlock a new account's pending send", async () => {
+  const old = deferred()
+  const f = fixture({ sendAgentMessage: () => old.promise })
+  f.store.setState({ selectedConversationId: 10 })
+  const sending = f.store.getState().sendMessage("For A", 10)
+  f.reset()
+  f.store.setState({ sending: true, selectedConversationId: 20 })
+  old.resolve({ id: 100, conversationId: 10 })
+  await sending
+  assert.equal(f.store.getState().sending, true)
+})
+
+test("attachment upload cannot send under a new account after identity change", async () => {
+  const upload = deferred()
+  let sends = 0
+  const f = fixture({
+    uploadAgentConversationAttachment: () => upload.promise,
+    sendAgentMessage: async () => { sends += 1; return { id: 100 } },
+  })
+  f.store.setState({ selectedConversationId: 10 })
+  const pending = f.store.getState().sendAttachment({}, 10)
+  f.session = { user: { id: 2 }, accessToken: "test-session-b" }
+  f.reset()
+  upload.resolve({ assetId: "test", filename: "test.txt" })
+  assert.equal(await pending, null)
+  assert.equal(sends, 0)
+})
+
+test("a fresh snapshot invalidates old pagination without leaving its loading flag stuck", async () => {
+  const oldPage = deferred()
+  const fresh = deferred()
+  const f = fixture({ fetchAgentMessages: (params) => params.cursor ? oldPage.promise : fresh.promise })
+  f.store.setState({ selectedConversationId: 10, messagesCursor: "100", messagesHasMore: true })
+  const older = f.store.getState().loadOlderMessages()
+  assert.equal(f.store.getState().messagesLoadingMore, true)
+  const refresh = f.store.getState().loadMessages(10)
+  fresh.resolve({ results: [{ id: 200 }], hasMore: true })
+  await refresh
+  oldPage.resolve({ results: [{ id: 50 }], hasMore: false })
+  await older
+  assert.equal(f.store.getState().messages[0].id, 200)
+  assert.equal(f.store.getState().messagesLoadingMore, false)
+})

web/lib/stores/agent-conversations.ts

@@ -1,3 +1,5 @@
+// Modified in the independent hardening fork; see docs/hardening/README.md.
+// Modified for AgentDeskFixes: guard private state, captured recipients, and stale async completions.
 "use client"
 
 import { create } from "zustand"
@@ -104,9 +106,9 @@ type AgentConversationsStore = {
   loadOlderMessages: () => Promise<void>
   syncLatestMessages: (conversationId: number) => Promise<void>
   markSelectedConversationRead: () => Promise<void>
-  sendMessage: (html: string) => Promise<AgentMessage | null>
-  uploadImage: (file: File) => Promise<AgentAsset | null>
-  sendAttachment: (file: File) => Promise<AgentMessage | null>
+  sendMessage: (html: string, conversationId?: number) => Promise<AgentMessage | null>
+  uploadImage: (file: File, conversationId?: number) => Promise<AgentAsset | null>
+  sendAttachment: (file: File, conversationId?: number) => Promise<AgentMessage | null>
   recallMessage: (messageId: number) => Promise<AgentMessage | null>
   applyRealtimeMessageCreated: (message: AgentMessage) => void
   applyRealtimeAgentActivity: (payload: AgentActivityEventPayload) => void
@@ -119,6 +121,22 @@ type AgentConversationsStore = {
 
 let conversationsRequestSeq = 0
 let messagesRequestSeq = 0
+let sessionGeneration = 0
+
+function captureSessionScope() {
+  const generation = sessionGeneration
+  const userId = readSession()?.user.id
+  return () =>
+    generation === sessionGeneration && Boolean(userId) && readSession()?.user.id === userId
+}
+
+/** Invalidates every outstanding request before removing private dashboard data. */
+export function resetAgentConversations() {
+  sessionGeneration += 1
+  conversationsRequestSeq += 1
+  messagesRequestSeq += 1
+  useAgentConversationsStore.setState(useAgentConversationsStore.getInitialState(), true)
+}
 
 export const useAgentConversationsStore = create<AgentConversationsStore>((set, get) => ({
   searchKeyword: "",
@@ -167,6 +185,8 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
   },
 
   loadConversations: async () => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession()) return
     const requestSeq = ++conversationsRequestSeq
     const store = get()
 
@@ -180,7 +200,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
       )
       const conversations = ensureArray(data.results)
 
-      if (requestSeq !== conversationsRequestSeq) {
+      if (requestSeq !== conversationsRequestSeq || !isCurrentSession()) {
         return
       }
 
@@ -216,7 +236,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         })
       }
     } catch (error) {
-      if (requestSeq === conversationsRequestSeq) {
+      if (requestSeq === conversationsRequestSeq && isCurrentSession()) {
         set({ conversationsLoading: false })
       }
       throw error
@@ -246,10 +266,14 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
   },
 
   loadMessages: async (conversationId, options = {}) => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession() || get().selectedConversationId !== conversationId) return
     const requestSeq = ++messagesRequestSeq
     const store = get()
     const shouldShowLoading =
       options.forceLoading || store.messagesLoadedConversationId !== conversationId
+    // A fresh snapshot supersedes any older page request in the prior generation.
+    set({ messagesLoadingMore: false })
 
     if (shouldShowLoading) {
       set({
@@ -270,7 +294,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         limit: 50,
       })
 
-      if (requestSeq !== messagesRequestSeq) {
+      if (requestSeq !== messagesRequestSeq || !isCurrentSession()) {
         return
       }
 
@@ -288,7 +312,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         messagesHasMore: Boolean(data.hasMore),
       })
     } catch (error) {
-      if (requestSeq === messagesRequestSeq) {
+      if (requestSeq === messagesRequestSeq && isCurrentSession()) {
         set({ messagesLoading: false })
       }
       throw error
@@ -296,6 +320,9 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
   },
 
   loadOlderMessages: async () => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession()) return
+    const selectionGeneration = messagesRequestSeq
     const conversationId = get().selectedConversationId
     if (!conversationId || get().messagesLoadingMore || !get().messagesHasMore) {
       return
@@ -312,7 +339,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         cursor: cursorId,
         limit: 50,
       })
-      if (get().selectedConversationId !== conversationId) {
+      if (!isCurrentSession() || selectionGeneration !== messagesRequestSeq || get().selectedConversationId !== conversationId) {
         return
       }
       const incoming = ensureArray(data.results)
@@ -328,12 +355,17 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         }
       })
     } catch (error) {
-      set({ messagesLoadingMore: false })
+      if (isCurrentSession() && selectionGeneration === messagesRequestSeq && get().selectedConversationId === conversationId) {
+        set({ messagesLoadingMore: false })
+      }
       throw error
     }
   },
 
   syncLatestMessages: async (conversationId) => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession()) return
+    const selectionGeneration = messagesRequestSeq
     if (conversationId <= 0) {
       return
     }
@@ -342,7 +374,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         conversationId,
         limit: 50,
       })
-      if (get().selectedConversationId !== conversationId) {
+      if (!isCurrentSession() || selectionGeneration !== messagesRequestSeq || get().selectedConversationId !== conversationId) {
         return
       }
       const batch = ensureArray(data.results)
@@ -370,6 +402,8 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
   },
 
   markSelectedConversationRead: async () => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession()) return
     const store = get()
     const conversationId = store.selectedConversationId
     const conversation = store.conversations.find((item) => item.id === conversationId)
@@ -390,6 +424,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
     set({ readingMessageId: lastMessage.id })
     try {
       await markAgentMessageRead(conversationId, lastMessage.id)
+      if (!isCurrentSession() || get().readingMessageId !== lastMessage.id) return
       set((current) => {
         if (current.selectedConversationId !== conversationId) {
           return { readingMessageId: 0 }
@@ -414,7 +449,9 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         }
       })
     } catch (error) {
-      set({ readingMessageId: 0 })
+      if (isCurrentSession() && get().readingMessageId === lastMessage.id) {
+        set({ readingMessageId: 0 })
+      }
       throw error
     }
   },
@@ -513,7 +550,10 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
   },
 
   resyncRealtimeData: async (conversationId) => {
+    const isCurrentSession = captureSessionScope()
+    if (!isCurrentSession()) return
     await get().loadConversations()
+    if (!isCurrentSession()) return
     const selectedConversationId = get().selectedConversationId
     const targetConversationId = conversationId ?? selectedConversationId
     if (targetConversationId && selectedConversationId === targetConversationId) {
@@ -524,10 +564,15 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
     }
   },
 
-  sendMessage: async (html) => {
+  sendMessage: async (html, recipientId) => {
+    const isCurrentSession = captureSessionScope()
     const trimmedContent = html.trim()
     const { selectedConversationId, sending } = get()
-    if (!selectedConversationId || !trimmedContent || sending) {
+    if (
+      !isCurrentSession() || !selectedConversationId ||
+      (recipientId !== undefined && recipientId !== selectedConversationId) ||
+      !trimmedContent || sending || get().uploadingAsset
+    ) {
       return null
     }
 
@@ -540,7 +585,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         clientMsgId: `agent_${generateUUID()}`,
       })
 
-      if (get().selectedConversationId === selectedConversationId) {
+      if (isCurrentSession() && get().selectedConversationId === selectedConversationId) {
         set((current) => ({
           messages: current.messages.some((m) => m.id === message.id)
             ? current.messages.map((m) => (m.id === message.id ? message : m))
@@ -561,33 +606,45 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
 
       return message
     } finally {
-      set({ sending: false })
+      if (isCurrentSession()) set({ sending: false })
     }
   },
 
-  uploadImage: async (file) => {
+  uploadImage: async (file, recipientId) => {
+    const isCurrentSession = captureSessionScope()
     const { selectedConversationId, sending, uploadingAsset } = get()
-    if (!selectedConversationId || sending || uploadingAsset) {
+    if (
+      !isCurrentSession() || !selectedConversationId ||
+      (recipientId !== undefined && recipientId !== selectedConversationId) ||
+      sending || uploadingAsset
+    ) {
       return null
     }
 
     set({ uploadingAsset: true })
     try {
-      return await uploadAgentConversationImage(selectedConversationId, file)
+      const asset = await uploadAgentConversationImage(selectedConversationId, file)
+      return isCurrentSession() ? asset : null
     } finally {
-      set({ uploadingAsset: false })
+      if (isCurrentSession()) set({ uploadingAsset: false })
     }
   },
 
-  sendAttachment: async (file) => {
+  sendAttachment: async (file, recipientId) => {
+    const isCurrentSession = captureSessionScope()
     const { selectedConversationId, sending, uploadingAsset } = get()
-    if (!selectedConversationId || sending || uploadingAsset) {
+    if (
+      !isCurrentSession() || !selectedConversationId ||
+      (recipientId !== undefined && recipientId !== selectedConversationId) ||
+      sending || uploadingAsset
+    ) {
       return null
     }
 
     set({ uploadingAsset: true })
     try {
       const asset = await uploadAgentConversationAttachment(selectedConversationId, file)
+      if (!isCurrentSession()) return null
       const message = await sendAgentMessage({
         conversationId: selectedConversationId,
         messageType: "attachment",
@@ -596,7 +653,7 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
         clientMsgId: `agent_attachment_${generateUUID()}`,
       })
 
-      if (get().selectedConversationId === selectedConversationId) {
+      if (isCurrentSession() && get().selectedConversationId === selectedConversationId) {
         set((current) => ({
           messages: current.messages.some((m) => m.id === message.id)
             ? current.messages.map((m) => (m.id === message.id ? message : m))
@@ -617,20 +674,22 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
 
       return message
     } finally {
-      set({ uploadingAsset: false })
+      if (isCurrentSession()) set({ uploadingAsset: false })
     }
   },
 
   recallMessage: async (messageId) => {
+    const isCurrentSession = captureSessionScope()
     const { selectedConversationId, recallingMessageId } = get()
-    if (!selectedConversationId || messageId <= 0 || recallingMessageId === messageId) {
+    if (!isCurrentSession() || !selectedConversationId || messageId <= 0 || recallingMessageId === messageId) {
       return null
     }
 
     set({ recallingMessageId: messageId })
     try {
       const message = await recallAgentMessage(messageId)
-      if (get().selectedConversationId === selectedConversationId) {
+      if (!isCurrentSession()) return null
+      if (isCurrentSession() && get().selectedConversationId === selectedConversationId) {
         set((current) => {
           const nextMessages = current.messages.map((item) =>
             item.id === message.id ? message : item
@@ -656,11 +715,11 @@ export const useAgentConversationsStore = create<AgentConversationsStore>((set,
           }
         })
       } else {
-        set({ recallingMessageId: 0 })
+        if (isCurrentSession() && get().recallingMessageId === messageId) set({ recallingMessageId: 0 })
       }
       return message
     } catch (error) {
-      set({ recallingMessageId: 0 })
+      if (isCurrentSession() && get().recallingMessageId === messageId) set({ recallingMessageId: 0 })
       throw error
     }
   },

web/lib/stores/support-chat-realtime.test.mjs

@@ -9,7 +9,8 @@ const deferred = () => {
   const promise = new Promise((done) => { resolve = done })
   return { promise, resolve }
 }
-const conversation = (id) => ({ id, status: 3, customerUnreadCount: 0 })
+const conversation = (id) => ({ id, channelId: 1, status: 3, lastMessageId: 0,
+  customerUnreadCount: 0, agentUnreadCount: 0, customerLastReadMessageId: 0, agentLastReadMessageId: 0 })
 const message = (id, conversationId) => ({ id, conversationId, senderType: "agent",
   senderId: 1, messageType: "html", content: "Reply", sendStatus: 1,
   customerRead: false, agentRead: false })
@@ -24,6 +25,8 @@ function harness(overrides = {}) {
   const config = { channelId: "fixture", externalId: "visitor-1" }
   const document = { visibilityState: "visible" }
   const api = {
+    getCustomerIdentityScope: () => JSON.stringify(config),
+    getCustomerEntryScope: () => JSON.stringify(config),
     ensureCustomerSession: async () => ({}),
     fetchImWidgetConfig: async () => ({}),
     fetchImConversationList: async () => page([conversation(1)]),
@@ -41,6 +44,7 @@ function harness(overrides = {}) {
       return { getState: () => state, setState: set }
     } },
     "@/lib/api/im": api,
+    "@/lib/message-file-identity": { getMessageFileIdentity: async () => "fixture-file" },
     "@/lib/im-realtime": { createImRealtimeConnection: () => {} },
     "@/lib/im-message": { summarizeIMMessage: (item) => item.content, parseMessageAssetPayload: () => null },
     "@/lib/utils": { generateUUID: () => "fixture" },
@@ -67,9 +71,9 @@ function harness(overrides = {}) {
     const compiled = ts.transpileModule(source, { compilerOptions: {
       target: ts.ScriptTarget.ES2022, module: ts.ModuleKind.CommonJS,
     } })
-    const module = { exports: {} }
-    modules.set(name, module.exports)
-    vm.runInNewContext(compiled.outputText, { module, exports: module.exports,
+    const moduleContext = { exports: {} }
+    modules.set(name, moduleContext.exports)
+    vm.runInNewContext(compiled.outputText, { module: moduleContext, exports: moduleContext.exports,
       require: load, console, document, AbortController, WebSocket: { OPEN: 1, CONNECTING: 0 },
       setTimeout: (callback, delay) => {
         const id = ++nextTimer
@@ -78,10 +82,10 @@ function harness(overrides = {}) {
       },
       clearTimeout: (id) => timers.delete(id),
     })
-    return module.exports
+    return moduleContext.exports
   }
   const store = load("./support-chat.ts").useSupportChatStore
-  store.setState({ initialized: true, isOpen: true, isVisible: true,
+  store.setState({ identityScope: api.getCustomerIdentityScope(), initialized: true, isOpen: true, isVisible: true,
     conversations: [conversation(1)], conversation: conversation(1), activeConversationId: 1 })
   return { store, api, config, document, timers, sent,
     get connects() { return connects }, get disconnects() { return disconnects },

web/lib/stores/support-chat.test.mjs

@@ -0,0 +1,289 @@
+import assert from "node:assert/strict"
+import { readFileSync } from "node:fs"
+import test from "node:test"
+import vm from "node:vm"
+import ts from "typescript"
+
+const deferred = () => {
+  let resolve, reject
+  const promise = new Promise((yes, no) => { resolve = yes; reject = no })
+  return { promise, resolve, reject }
+}
+const conversation = (id, extra = {}) => ({ id, channelId: 1, customerName: "Visitor", status: 3,
+  serviceMode: 1, priority: 0, currentAssigneeId: 0, lastMessageId: 0,
+  customerUnreadCount: 0, agentUnreadCount: 0, customerLastReadMessageId: 0,
+  agentLastReadMessageId: 0, ...extra })
+const message = (id, conversationId, extra = {}) => ({ id, conversationId,
+  senderType: "customer", senderId: 1, messageType: "html", content: `<p>${id}</p>`,
+  sendStatus: 1, customerRead: false, agentRead: false, ...extra })
+const page = (results, hasMore = false) => ({ results, hasMore })
+
+// Exercise the actual store, including its asynchronous continuations, without
+// connecting a socket, browser, database, or service.
+function harness(overrides = {}) {
+  let identity = "visitor-1", uuid = 0, state, realtimeOptions
+  let connectCount = 0, disconnectCount = 0
+  const timers = new Map()
+  const api = {
+    getCustomerIdentityScope: () => identity,
+    getCustomerEntryScope: () => identity,
+    ensureCustomerSession: async () => ({}),
+    fetchImWidgetConfig: async () => ({}),
+    fetchImConversationList: async () => page([conversation(1), conversation(2)]),
+    createOrMatchImConversation: async () => conversation(1),
+    fetchImMessages: async () => page([]),
+    createImConversation: async () => conversation(3),
+    markImMessageRead: async () => {},
+    closeImConversation: async () => {},
+    applyCustomerSessionRefresh: () => {},
+    ...overrides,
+  }
+  const modules = new Map()
+  const mocks = {
+    zustand: { create: (initializer) => {
+      const set = (patch) => { state = { ...state, ...(typeof patch === "function" ? patch(state) : patch) } }
+      state = initializer(set, () => state)
+      return { getState: () => state, setState: set }
+    } },
+    "@/lib/api/im": api,
+    "@/lib/message-file-identity": { getMessageFileIdentity: async (file) => file.content },
+    "@/lib/im-realtime": { createImRealtimeConnection: () => {} },
+    "@/lib/im-message": { summarizeIMMessage: (item) => item.content, parseMessageAssetPayload: () => null },
+    "@/lib/utils": { generateUUID: () => `uuid-${++uuid}` },
+    "@/i18n/messages": { translateCurrentMessage: (key) => key },
+    "@/lib/sdk/runtime-config": { readSupportChatRuntimeConfig: () => ({}), setSupportChatRuntimeConfig: () => {} },
+    "@/lib/realtime-connection": { createRealtimeConnectionManager: (options) => {
+      realtimeOptions = options
+      return { connect: async () => { connectCount++ }, disconnect: () => { disconnectCount++ } }
+    } },
+  }
+  const load = (name) => {
+    if (mocks[name]) return mocks[name]
+    if (modules.has(name)) return modules.get(name)
+    const url = name.startsWith("@/")
+      ? new URL(`../../${name.slice(2)}.ts`, import.meta.url)
+      : new URL(name, import.meta.url)
+    const source = readFileSync(url, "utf8")
+    const compiled = ts.transpileModule(source, { compilerOptions: {
+      target: ts.ScriptTarget.ES2022, module: ts.ModuleKind.CommonJS,
+    } })
+    const moduleContext = { exports: {} }
+    modules.set(name, moduleContext.exports)
+    vm.runInNewContext(compiled.outputText, { module: moduleContext, exports: moduleContext.exports, require: load,
+      console, AbortController, setTimeout: (callback) => { const id = timers.size + 1; timers.set(id, callback); return id },
+      clearTimeout: (id) => timers.delete(id), WebSocket: { OPEN: 1, CONNECTING: 0 } })
+    return moduleContext.exports
+  }
+  const store = load("./support-chat.ts").useSupportChatStore
+  const seed = (extra = {}) => store.setState({ identityScope: identity, initialized: true,
+    conversations: [conversation(1), conversation(2)], activeConversationId: 1,
+    conversation: conversation(1), ...extra })
+  seed()
+  return { store, api, seed, timers, setIdentity: (value) => { identity = value },
+    emit: (type, data) => realtimeOptions.onMessage({ data: JSON.stringify({ type, data }) }),
+    get connectCount() { return connectCount }, get disconnectCount() { return disconnectCount } }
+}
+
+for (const loader of ["refreshMessages", "syncLatestMessages", "loadOlderMessages"]) {
+  test(`${loader} cannot paint a late response into a newly selected request`, async () => {
+    const late = deferred()
+    const h = harness({ fetchImMessages: ({ conversationId }) => conversationId === 1 ? late.promise : Promise.resolve(page([message(20, 2)])) })
+    h.seed({ messages: [message(10, 1)], messagesHasMore: true, messagesCursor: "10" })
+    const pending = h.store.getState()[loader]()
+    await h.store.getState().selectConversation(2)
+    late.resolve(page([message(5, 1)], true))
+    await pending
+    assert.equal(h.store.getState().conversation.id, 2)
+    assert.deepEqual(Array.from(h.store.getState().messages, (item) => item.conversationId), [2])
+    assert.equal(h.store.getState().messagesLoadingMore, false)
+  })
+}
+
+test("A to B to A selection invalidates the first A response", async () => {
+  const late = deferred()
+  let calls = 0
+  const h = harness({ fetchImMessages: ({ conversationId }) => conversationId === 1 && calls++ === 0
+    ? late.promise : Promise.resolve(page([message(30, conversationId)])) })
+  const pending = h.store.getState().refreshMessages()
+  await h.store.getState().selectConversation(2)
+  await h.store.getState().selectConversation(1)
+  late.resolve(page([message(10, 1)]))
+  await pending
+  assert.deepEqual(Array.from(h.store.getState().messages, (item) => item.id), [30])
+})
+
+test("newer latest request wins and stale failure cannot replace its error state", async () => {
+  const old = deferred(), current = deferred()
+  let calls = 0
+  const h = harness({ fetchImMessages: () => ++calls === 1 ? old.promise : current.promise })
+  const first = h.store.getState().refreshMessages()
+  const second = h.store.getState().refreshMessages()
+  current.resolve(page([message(30, 1)]))
+  await second
+  old.reject(new Error("stale error"))
+  await first
+  assert.equal(h.store.getState().error, "")
+  assert.equal(h.store.getState().messages[0].id, 30)
+})
+
+test("read acknowledgment updates its original list row without marking the new view", async () => {
+  const read = deferred()
+  const h = harness({ markImMessageRead: () => read.promise, fetchImMessages: async () => page([message(20, 2)]) })
+  const first = conversation(1, { lastMessageId: 10, customerUnreadCount: 1 })
+  h.seed({ conversations: [first, conversation(2, { customerUnreadCount: 2 })], conversation: first, messages: [message(10, 1)] })
+  const pending = h.store.getState().markConversationRead()
+  await h.store.getState().selectConversation(2)
+  read.resolve()
+  await pending
+  const state = h.store.getState()
+  assert.equal(state.conversations.find((item) => item.id === 1).customerUnreadCount, 0)
+  assert.equal(state.conversation.customerUnreadCount, 2)
+  assert.equal(state.messages[0].customerRead, false)
+})
+
+test("read acknowledgment does not erase a newer unread reply", async () => {
+  const read = deferred()
+  const h = harness({ markImMessageRead: () => read.promise })
+  const first = conversation(1, { lastMessageId: 10, customerUnreadCount: 1 })
+  h.seed({ conversations: [first], conversation: first, messages: [message(10, 1)] })
+  const pending = h.store.getState().markConversationRead()
+  h.emit("conversation.updated", { conversationId: 1, lastMessageId: 11, customerUnreadCount: 2 })
+  read.resolve()
+  await pending
+  assert.equal(h.store.getState().conversation.customerUnreadCount, 2)
+  assert.equal(h.store.getState().conversation.customerLastReadMessageId, 10)
+})
+
+test("send is single-flight and failed logical send keeps its idempotency key", async () => {
+  const first = deferred(), sent = []
+  const h = harness({ sendImMessage: (payload) => { sent.push(payload); return sent.length === 1 ? first.promise : Promise.resolve(message(10, 1)) } })
+  const pending = h.store.getState().handleSendMessage("<p>Hello</p>")
+  await assert.rejects(h.store.getState().handleSendMessage("<p>Hello</p>"), /sendInProgress/)
+  assert.equal(sent.length, 1)
+  first.reject(new Error("response lost"))
+  await assert.rejects(pending, /response lost/)
+  await h.store.getState().handleSendMessage("<p>Hello</p>")
+  assert.equal(sent[0].clientMsgId, sent[1].clientMsgId)
+  await h.store.getState().handleSendMessage("<p>Hello</p>")
+  assert.notEqual(sent[1].clientMsgId, sent[2].clientMsgId)
+})
+
+test("delivered send after switching updates only original request summary", async () => {
+  const send = deferred()
+  const h = harness({ sendImMessage: () => send.promise, fetchImMessages: async () => page([message(20, 2)]) })
+  const pending = h.store.getState().handleSendMessage("hello")
+  await h.store.getState().selectConversation(2)
+  assert.equal(h.store.getState().sending, false)
+  send.resolve(message(10, 1))
+  await pending
+  const state = h.store.getState()
+  assert.equal(state.conversations.find((item) => item.id === 1).lastMessageId, 10)
+  assert.equal(state.conversation.lastMessageId, 0)
+  assert.equal(state.messages[0].conversationId, 2)
+})
+
+test("close response for old selection does not close or disconnect current request", async () => {
+  const close = deferred()
+  const h = harness({ closeImConversation: () => close.promise })
+  const pending = h.store.getState().closeConversation()
+  await h.store.getState().selectConversation(2)
+  close.resolve()
+  await pending
+  assert.equal(h.store.getState().conversation.status, 3)
+  assert.equal(h.store.getState().conversations.find((item) => item.id === 1).status, 4)
+  assert.equal(h.disconnectCount, 0)
+})
+
+test("identity change invalidates old delivered result even for same numeric conversation", async () => {
+  const send = deferred()
+  const h = harness({ sendImMessage: () => send.promise })
+  const pending = h.store.getState().handleSendMessage("private")
+  h.setIdentity("visitor-2")
+  h.seed()
+  send.resolve(message(10, 1))
+  await pending
+  assert.equal(h.store.getState().messages.length, 0)
+  assert.equal(h.store.getState().conversation.lastMessageId, 0)
+})
+
+test("unmount invalidates pending bootstrap and prevents sockets from reopening", async () => {
+  const config = deferred()
+  const h = harness({ fetchImWidgetConfig: () => config.promise })
+  h.seed({ initialized: false, isOpen: true, conversation: null, activeConversationId: 0 })
+  const pending = h.store.getState().bootstrap()
+  h.store.getState().disconnectSocket()
+  config.resolve({ title: "stale" })
+  await pending
+  assert.equal(h.store.getState().conversation, null)
+  assert.equal(h.connectCount, 0)
+})
+
+test("retry reboots a failed initial load, and concurrent bootstrap is single-flight", async () => {
+  let listCalls = 0
+  const config = deferred()
+  const h = harness({ fetchImWidgetConfig: () => config.promise,
+    fetchImConversationList: async () => { if (++listCalls === 1) throw new Error("offline"); return page([conversation(1)]) } })
+  h.seed({ initialized: false, isOpen: true, conversation: null, activeConversationId: 0 })
+  const first = h.store.getState().bootstrap()
+  assert.equal(h.store.getState().bootstrap(), first)
+  config.resolve({})
+  await first
+  assert.equal(h.store.getState().conversation, null)
+  await h.store.getState().retry()
+  assert.equal(h.store.getState().conversation.id, 1)
+  assert.equal(h.store.getState().error, "")
+})
+
+test("new request and request switching reconnect after transport was disconnected", async () => {
+  const h = harness()
+  h.seed({ isOpen: true, socket: null })
+  await h.store.getState().startNewConversation()
+  assert.equal(h.store.getState().conversation.id, 3)
+  assert.ok(h.connectCount > 0)
+  const connects = h.connectCount
+  await h.store.getState().selectConversation(2)
+  assert.ok(h.connectCount > connects)
+})
+
+test("list refresh cannot overwrite a delivered send that happened after its snapshot", async () => {
+  const list = deferred()
+  const h = harness({ fetchImConversationList: () => list.promise,
+    sendImMessage: async () => message(10, 1) })
+  const pending = h.store.getState().refreshConversations()
+  await h.store.getState().handleSendMessage("hello")
+  list.resolve(page([conversation(1), conversation(2)]))
+  await pending
+  assert.equal(h.store.getState().conversation.lastMessageId, 10)
+})
+
+test("image upload completes into captured draft even after selecting another request", async () => {
+  const upload = deferred()
+  const h = harness({ uploadImImage: () => upload.promise })
+  const pending = h.store.getState().uploadMessageImage({})
+  await h.store.getState().selectConversation(2)
+  const asset = { assetId: "image-1" }
+  upload.resolve(asset)
+  assert.equal(await pending, asset)
+})
+
+test("changed identity clears private state while closed, before reopening", async () => {
+  const h = harness()
+  h.seed({ messages: [message(10, 1)], isOpen: false })
+  h.setIdentity("visitor-2")
+  await h.store.getState().bootstrap()
+  assert.equal(h.store.getState().conversation, null)
+  assert.equal(h.store.getState().conversations.length, 0)
+  assert.equal(h.store.getState().messages.length, 0)
+  assert.equal(h.store.getState().identityScope, "visitor-2")
+})
+
+test("reselected attachment reuses upload and logical send key after uncertain failure", async () => {
+  const sent = []
+  let uploads = 0
+  const h = harness({ uploadImAttachment: async () => { uploads++; return { assetId: "asset-1", filename: "attachment.txt" } },
+    sendImMessage: async (payload) => { sent.push(payload); if (sent.length === 1) throw new Error("ack lost"); return message(10, 1) } })
+  await assert.rejects(h.store.getState().sendAttachment({ content: "same file" }), /ack lost/)
+  await h.store.getState().sendAttachment({ content: "same file" })
+  assert.equal(uploads, 1)
+  assert.equal(sent[0].clientMsgId, sent[1].clientMsgId)
+})