fix(mqtt): add pause and resume control for message stream

apps/desktop/src/components/mqtt/MqttAdminConsole.vue

@@ -9,7 +9,7 @@ import TopicTreeNode from "./TopicTreeNode.vue";
 import MqttPublishPanel from "./MqttPublishDialog.vue";
 import { decodePayload, PAYLOAD_ENCODINGS, PAYLOAD_ENCODING_LABELS, type PayloadEncoding } from "@/lib/mqtt/mqttPayloadCodec";
 import { safeLocalStorageGet, safeLocalStorageSet } from "@/lib/backend/safeStorage";
-import { ChevronDown, ChevronUp } from "@lucide/vue";
+import { ChevronDown, ChevronUp, Pause, Play } from "@lucide/vue";
 
 interface Props {
   connectionId: string;
@@ -27,6 +27,7 @@ const selectedTopic = ref<string>(props.initialTopic ?? "");
 const loading = ref(true);
 const error = ref<string | null>(null);
 const pollingTimer = ref<ReturnType<typeof setInterval> | null>(null);
+const messagesPaused = ref(false);
 const displayEncoding = ref<PayloadEncoding>("plaintext");
 const topicSearch = ref("");
 const showSubscriptionDialog = ref(false);
@@ -218,8 +219,10 @@ async function handleClearMessages() {
 function startPolling() {
   stopPolling();
   pollingTimer.value = setInterval(async () => {
+    if (messagesPaused.value) return;
     try {
-      messages.value = (await mqttGetMessages(props.connectionId, selectedTopic.value || undefined, 50)) as MqttMessage[];
+      const nextMessages = (await mqttGetMessages(props.connectionId, selectedTopic.value || undefined, 50)) as MqttMessage[];
+      if (!messagesPaused.value) messages.value = nextMessages;
     } catch {
       /* ignore polling errors */
     }
@@ -233,6 +236,10 @@ function stopPolling() {
   }
 }
 
+function toggleMessagesPaused() {
+  messagesPaused.value = !messagesPaused.value;
+}
+
 function formatMessagePayload(msg: MqttMessage): string {
   if (displayEncoding.value === "plaintext" && msg.payloadText != null) return msg.payloadText;
   return decodePayload(msg.payloadBase64, displayEncoding.value);
@@ -326,6 +333,11 @@ onUnmounted(stopPolling);
               <select v-model="displayEncoding" class="h-6 rounded border bg-transparent px-1.5 text-[11px] text-muted-foreground outline-none">
                 <option v-for="enc in PAYLOAD_ENCODINGS" :key="enc" :value="enc">{{ PAYLOAD_ENCODING_LABELS[enc] }}</option>
               </select>
+              <Button size="sm" variant="ghost" class="h-6 gap-1 px-2 text-[11px] font-normal normal-case" :title="messagesPaused ? t('connection.mqttResumeMessages') : t('connection.mqttPauseMessages')" @click="toggleMessagesPaused">
+                <Play v-if="messagesPaused" class="h-3.5 w-3.5" />
+                <Pause v-else class="h-3.5 w-3.5" />
+                <span>{{ messagesPaused ? t("connection.mqttResumeMessages") : t("connection.mqttPauseMessages") }}</span>
+              </Button>
               <Button
                 size="sm"
                 variant="ghost"

apps/desktop/src/components/mqtt/__tests__/MqttAdminConsolePause.spec.ts

@@ -0,0 +1,128 @@
+// @vitest-environment happy-dom
+
+import { createApp, nextTick, type App } from "vue";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import i18n, { loadLocaleMessages } from "@/i18n";
+import MqttAdminConsole from "@/components/mqtt/MqttAdminConsole.vue";
+import type { MqttBrokerInfo, MqttMessage } from "@/types/mqtt";
+
+const { mqttGetMessagesMock } = vi.hoisted(() => ({
+  mqttGetMessagesMock: vi.fn(),
+}));
+
+vi.mock("@/lib/backend/api", () => ({
+  mqttGetBrokerInfo: vi.fn(
+    async (): Promise<MqttBrokerInfo> => ({
+      brokerUrl: "mqtt://localhost:1883",
+      clientId: "dbx-test",
+      connected: true,
+      protocolVersion: "5.0",
+      subscriptionCount: 1,
+    }),
+  ),
+  mqttListTopics: vi.fn(async () => [["device/status", "atmostonce"]]),
+  mqttListSavedTopicConfigs: vi.fn(async () => [{ topic: "device/status", qos: "atmostonce", enabled: true, noLocal: false }]),
+  mqttGetMessages: mqttGetMessagesMock,
+  mqttSubscribe: vi.fn(),
+  mqttUnsubscribe: vi.fn(),
+  mqttSaveTopicConfig: vi.fn(),
+  mqttDeleteTopicConfig: vi.fn(),
+  mqttClearMessages: vi.fn(),
+}));
+
+const mountedApps: App[] = [];
+
+function messageAt(index: number): MqttMessage {
+  return {
+    topic: "device/status",
+    payloadBase64: btoa(`payload-${index}`),
+    payloadText: `payload-${index}`,
+    qos: 0,
+    retain: false,
+    receivedAtMs: Date.now(),
+    direction: "received",
+  };
+}
+
+async function mountConsole() {
+  const container = document.createElement("div");
+  document.body.append(container);
+  const app = createApp(MqttAdminConsole, {
+    connectionId: "mqtt-connection-1",
+    initialTopic: "device/status",
+  });
+  mountedApps.push(app);
+  app.use(i18n);
+  app.mount(container);
+  await nextTick();
+  return container;
+}
+
+beforeEach(async () => {
+  mqttGetMessagesMock.mockReset().mockResolvedValue([messageAt(0)]);
+  await loadLocaleMessages("zh-CN");
+  i18n.global.locale.value = "zh-CN";
+  vi.useFakeTimers();
+});
+
+afterEach(() => {
+  vi.useRealTimers();
+  for (const app of mountedApps.splice(0)) app.unmount();
+  document.body.innerHTML = "";
+});
+
+describe("MQTT 控制台消息暂停自动滚动 (issue #5615)", () => {
+  it("暂停期间不会应用已经在途的轮询结果", async () => {
+    let resolvePollingRequest!: (messages: MqttMessage[]) => void;
+    mqttGetMessagesMock.mockResolvedValueOnce([messageAt(0)]).mockReturnValueOnce(
+      new Promise<MqttMessage[]>((resolve) => {
+        resolvePollingRequest = resolve;
+      }),
+    );
+
+    const container = await mountConsole();
+    await Promise.resolve();
+    await Promise.resolve();
+    await nextTick();
+    expect(container.textContent).toContain("payload-0");
+
+    vi.advanceTimersByTime(3000);
+    await Promise.resolve();
+    expect(mqttGetMessagesMock).toHaveBeenCalledTimes(2);
+
+    const pauseButton = Array.from(container.querySelectorAll("button")).find((button) => button.textContent?.includes("暂停"));
+    pauseButton?.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    await nextTick();
+
+    resolvePollingRequest([messageAt(1)]);
+    await Promise.resolve();
+    await nextTick();
+
+    expect(container.textContent).toContain("payload-0");
+    expect(container.textContent).not.toContain("payload-1");
+  });
+
+  it("点击暂停后，轮询不再覆盖消息列表", async () => {
+    const container = await mountConsole();
+    await vi.runOnlyPendingTimersAsync();
+    const callsBeforePause = mqttGetMessagesMock.mock.calls.length;
+    expect(callsBeforePause).toBeGreaterThan(0);
+
+    const pauseButton = Array.from(container.querySelectorAll("button")).find((button) => button.textContent?.includes("暂停"));
+    expect(pauseButton).toBeTruthy();
+    pauseButton?.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    await nextTick();
+
+    mqttGetMessagesMock.mockClear();
+    await vi.advanceTimersByTimeAsync(3000);
+    await vi.advanceTimersByTimeAsync(3000);
+    expect(mqttGetMessagesMock).not.toHaveBeenCalled();
+
+    const resumeButton = Array.from(container.querySelectorAll("button")).find((button) => button.textContent?.includes("继续"));
+    expect(resumeButton).toBeTruthy();
+    resumeButton?.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    await nextTick();
+    await vi.advanceTimersByTimeAsync(3000);
+    expect(mqttGetMessagesMock).toHaveBeenCalled();
+  });
+});