feat: add file watcher for sending debug messages from external file

lib/rpc/rpc-client-real-device.js

@@ -1,22 +1,30 @@
 import log from '../logger';
-import { RpcClient } from './rpc-client';
-import { services } from 'appium-ios-device';
-
+import {RpcClient} from './rpc-client';
+import {services} from 'appium-ios-device';
+import fs from 'fs/promises';
+import fsSync from 'fs';
 
 export class RpcClientRealDevice extends RpcClient {
   /**
    * @param {import('./rpc-client').RpcClientOptions} [opts={}]
    */
-  constructor (opts = {}) {
-    super(Object.assign({
-      shouldCheckForTarget: false,
-    }, opts));
+  constructor(opts = {}) {
+    super(
+      Object.assign(
+        {
+          shouldCheckForTarget: false,
+        },
+        opts,
+      ),
+    );
+    this.fileWatcher = null;
+    this.lastPosition = 0;
   }
 
   /**
    * @override
    */
-  async connect () {
+  async connect() {
     this.service = await services.startWebInspectorService(this.udid, {
       osVersion: this.platformVersion,
       isSimulator: false,
@@ -28,17 +36,24 @@ export class RpcClientRealDevice extends RpcClient {
 
     this.service.listenMessage(this.receive.bind(this));
     this.isConnected = true;
+
+    // Start watching the file for new data to send
+    this.startFileWatcher();
   }
 
   /**
    * @override
    */
-  async disconnect () {
+  async disconnect() {
     if (!this.isConnected) {
       return;
     }
 
     log.debug('Disconnecting from remote debugger');
+
+    // Stop file watcher
+    this.stopFileWatcher();
+
     await super.disconnect();
     this.service.close();
     this.isConnected = false;
@@ -47,20 +62,91 @@ export class RpcClientRealDevice extends RpcClient {
   /**
    * @override
    */
-  async sendMessage (cmd) {
+  async sendMessage(cmd) {
     this.service.sendMessage(cmd);
   }
 
   /**
    * @override
    */
-  async receive (data) {
+  async receive(data) {
     if (!this.isConnected) {
       return;
     }
+
+    if (data && data.__argument && data.__argument.WIRMessageDataKey) {
+      const messageData = data.__argument.WIRMessageDataKey;
+      // console.log(`<< Received message data: ${messageData.toString('utf8')}`);
+      // append to a file in /tmp for debugging
+      // await fs.appendFile(`/tmp/wir-message.bin`, messageData.toString('utf8'));
+      await fs.appendFile('/tmp/wir-message.bin', messageData.toString('utf8') + require('os').EOL);
+    }
     // @ts-ignore messageHandler must be defined here
     await this.messageHandler.handleMessage(data);
   }
+
+  /**
+   * Start watching the file for new data to send
+   */
+  startFileWatcher() {
+    const filePath = '/tmp/wir-tobe-sent.bin';
+
+    // Initialize last position to end of file if it exists
+    if (fsSync.existsSync(filePath)) {
+      const stats = fsSync.statSync(filePath);
+      this.lastPosition = stats.size;
+    }
+
+    // Watch the file for changes
+    this.fileWatcher = fsSync.watch(filePath, (eventType) => {
+      if (eventType === 'change') {
+        this.handleFileChange(filePath);
+      }
+    });
+
+    log.debug(`Started watching ${filePath} for new data to send`);
+  }
+
+  /**
+   * Stop watching the file
+   */
+  stopFileWatcher() {
+    if (this.fileWatcher) {
+      this.fileWatcher.close();
+      this.fileWatcher = null;
+      log.debug('Stopped file watcher');
+    }
+  }
+
+  /**
+   * Handle file change events and send new data
+   */
+  async handleFileChange(filePath) {
+    try {
+      const stats = fsSync.statSync(filePath);
+      if (stats.size <= this.lastPosition) {
+        return; // No new data
+      }
+
+      // Read new data
+      const buffer = Buffer.alloc(stats.size - this.lastPosition);
+      const fd = fsSync.openSync(filePath, 'r');
+      fsSync.readSync(fd, buffer, 0, buffer.length, this.lastPosition);
+      fsSync.closeSync(fd);
+
+      // Update position
+      this.lastPosition = stats.size;
+
+      // Convert buffer to string and send
+      const data = buffer.toString('utf8').trim();
+      if (data) {
+        log.debug(`Sending data from file: ${data}`);
+        this.service.sendMessage(data);
+      }
+    } catch (error) {
+      log.error(`Error handling file change: ${error.message}`);
+    }
+  }
 }
 
 export default RpcClientRealDevice;