fix(transport): UdpApi trigger transport-interface-change

fix missing device disconnect or late device connect events

packages/transport/src/api/udp.ts

@@ -1,18 +1,19 @@
 import UDP from 'dgram';
-import { isNotUndefined } from '@trezor/utils';
+import { isNotUndefined, arrayPartition } from '@trezor/utils';
 
 import {
     AbstractApi,
     AbstractApiAwaitedResult,
     AbstractApiConstructorParams,
     DEVICE_TYPE,
 } from './abstract';
-
+import { DescriptorApiLevel } from '../types';
 import * as ERRORS from '../errors';
 
 export class UdpApi extends AbstractApi {
     chunkSize = 64;
 
+    protected devices: DescriptorApiLevel[] = [];
     protected interface = UDP.createSocket('udp4');
     protected communicating = false;
 
@@ -33,13 +34,31 @@ export class UdpApi extends AbstractApi {
             if (!this.listening) return;
 
             this.enumerationTimeout = setTimeout(() => {
-                this.enumerate(this.enumerateAbortController.signal).finally(enumerateRecursive);
+                this.enumerate(this.enumerateAbortController.signal)
+                    .then(r => this.handleEnumerate(r))
+                    .finally(enumerateRecursive);
             }, 500);
         };
 
         enumerateRecursive();
     }
 
+    private handleEnumerate(result: Awaited<ReturnType<typeof this.enumerate>>) {
+        if (result.success) {
+            const [known, unknown] = arrayPartition(result.payload, device =>
+                this.devices.includes(device),
+            );
+
+            if (known.length !== this.devices.length || unknown.length > 0) {
+                this.devices = result.payload;
+                this.emit('transport-interface-change', this.devices);
+            }
+        } else if (this.devices.length > 0) {
+            this.devices = [];
+            this.emit('transport-interface-change', this.devices);
+        }
+    }
+
     public write(path: string, buffer: Buffer, signal?: AbortSignal) {
         const [hostname, port] = path.split(':');