fix: availability checks not stopped on extension stop

lib/extension/availability.ts

@@ -17,6 +17,7 @@ export default class Availability extends Extension {
     private retrieveStateDebouncers: {[s: string]: () => void} = {};
     private pingQueue: Device[] = [];
     private pingQueueExecuting = false;
+    private stopped = false;
 
     private getTimeout(device: Device): number {
         if (typeof device.options.availability === 'object' && device.options.availability?.timeout != null) {
@@ -92,6 +93,11 @@ export default class Availability extends Extension {
             }
         }
 
+        if (this.stopped) {
+            // Exit here to avoid triggering any follow-up activity (e.g., re-queuing another ping attempt).
+            return;
+        }
+
         this.publishAvailability(device, !pingedSuccessfully);
         this.resetTimer(device);
         this.removeFromPingQueue(device);
@@ -103,6 +109,10 @@ export default class Availability extends Extension {
     }
 
     override async start(): Promise<void> {
+        if (this.stopped) {
+            throw new Error('This extension cannot be restarted.');
+        }
+
         this.eventBus.onEntityRenamed(this, (data) => {
             if (utils.isAvailabilityEnabledForEntity(data.entity, settings.get())) {
                 this.mqtt.publish(`${data.from}/availability`, null, {retain: true, qos: 1});
@@ -183,8 +193,10 @@ export default class Availability extends Extension {
     }
 
     override async stop(): Promise<void> {
+        this.stopped = true;
+        this.pingQueue = [];
         Object.values(this.timers).forEach((t) => clearTimeout(t));
-        super.stop();
+        await super.stop();
     }
 
     private retrieveState(device: Device): void {

test/availability.test.js

@@ -6,6 +6,7 @@ import zigbeeHerdsman from './stub/zigbeeHerdsman';
 import utils from '../lib/util/utils';
 import * as settings from '../lib/util/settings';
 import Controller from '../lib/controller';
+import Availability from '../lib/extension/availability';
 import flushPromises from './lib/flushPromises';
 import stringify from 'json-stable-stringify-without-jsonify';
 
@@ -344,4 +345,28 @@ describe('Availability', () => {
         expect(MQTT.publish).toHaveBeenCalledWith('zigbee2mqtt/group_tradfri_remote/availability',
             'online', {retain: true, qos: 1}, expect.any(Function));
     });
+
+    it('Should clear the ping queue on stop', async () => {
+        const availability = controller.extensions.find((extension) => extension instanceof Availability);
+        const publishAvailabilitySpy = jest.spyOn(availability, 'publishAvailability');
+
+        devices.bulb_color.zh = { ping: jest.fn().mockImplementation(() => new Promise((resolve) => setTimeout(resolve, 1000)))};
+        availability.addToPingQueue(devices.bulb_color);
+        availability.addToPingQueue(devices.bulb_color_2);
+
+        await availability.stop();
+        await advancedTime(utils.minutes(1));
+
+        expect(availability.pingQueue).toEqual([]);
+        // Validate the stop-interrupt implicitly by checking that it prevents further function invocations
+        expect(publishAvailabilitySpy).not.toHaveBeenCalled();
+    });
+
+    it('Should prevent instance restart', async () => {
+        const availability = controller.extensions.find((extension) => extension instanceof Availability);
+
+        await availability.stop();
+
+        await expect(() => availability.start()).rejects.toThrowError();
+    });
 });