fix: improve proxy deactivation (#83)

- Add more logs
- Check proxy configuration before applying it
- Rename getGlobalProxyValue function to getCurrentWifiProxyConfig
- Add additional checks on adb command response when retrieving the current wifi proxy conf

Author: vdanti

src/plugin.ts

@@ -4,7 +4,7 @@ import { Application } from 'express';
 import { CliArg, ISessionCapability, MockConfig, RecordConfig, RequestInfo, ReplayConfig, SniffConfig } from './types';
 import { DefaultPluginArgs, IPluginArgs } from './interfaces';
 import _ from 'lodash';
-import { configureWifiProxy, isRealDevice, getGlobalProxyValue, getAdbReverseTunnels } from './utils/adb';
+import { configureWifiProxy, isRealDevice, getCurrentWifiProxyConfig, getAdbReverseTunnels } from './utils/adb';
 import { cleanUpProxyServer, sanitizeMockConfig, setupProxyServer } from './utils/proxy';
 import proxyCache from './proxy-cache';
 import logger from './logger';
@@ -107,8 +107,8 @@ export class AppiumInterceptorPlugin extends BasePlugin {
         return response;
       }
       const realDevice = await isRealDevice(adb, deviceUDID);
-      const currentGlobalProxy = await getGlobalProxyValue(adb, deviceUDID)
-      const proxy = await setupProxyServer(sessionId, deviceUDID, realDevice, certDirectory, currentGlobalProxy);
+      const currentWifiProxyConfig = await getCurrentWifiProxyConfig(adb, deviceUDID)
+      const proxy = await setupProxyServer(sessionId, deviceUDID, realDevice, certDirectory, currentWifiProxyConfig);
       await configureWifiProxy(adb, deviceUDID, realDevice, proxy.options);
       proxyCache.add(sessionId, proxy);
     }

src/proxy.ts

@@ -29,7 +29,7 @@ export interface ProxyOptions {
   certificatePath: string;
   port: number;
   ip: string;
-  previousGlobalProxy?: ProxyOptions;
+  previousConfig?: ProxyOptions;
 }
 
 export class Proxy {
@@ -83,7 +83,7 @@ export class Proxy {
   }
 
   public get previousGlobalProxy(): ProxyOptions | undefined {
-    return this.options.previousGlobalProxy ?? undefined
+    return this.options.previousConfig ?? undefined
   }
 
   public async start(): Promise<boolean> {

src/utils/adb.ts

@@ -1,5 +1,6 @@
 import ADB from 'appium-adb';
 import { Proxy, ProxyOptions } from '../proxy';
+import logger from '../logger';
 
 export type ADBInstance = ADB;
 export type UDID = string;
@@ -25,17 +26,42 @@ export async function isRealDevice(adb: ADBInstance, udid: UDID): Promise<boolea
   return property !== 'emulator';
 }
 
+/**
+ * Configures the global HTTP proxy settings for Wi-Fi traffic on the target Android device via ADB.
+ * If a valid proxy configuration is provided:
+ * 1. It sets up an 'adb reverse' tunnel for real devices to ensure the device can reach the host-side proxy.
+ * 2. It sets the 'http_proxy' global setting to 'IP:PORT'.
+ * If the configuration is invalid or missing, it sets the 'http_proxy' to ':0' (which disables the proxy).
+ *
+ * @param adb - The ADB instance established by Appium.
+ * @param udid - The Unique Device Identifier (UDID) of the Android device or emulator.
+ * @param isRealDevice - Boolean indicating if the target is a physical device (requires adb reverse).
+ * @param proxyConfig - Optional configuration object containing the IP and port for the proxy.
+ * @returns A Promise resolving to the output of the final ADB shell command.
+ * @throws {Error} Throws an error if any ADB command execution fails.
+ */
 export async function configureWifiProxy(
   adb: ADBInstance,
   udid: UDID,
-  realDevice: boolean,
-  proxy?: ProxyOptions
+  isRealDevice: boolean,
+  proxyConfig?: ProxyOptions
 ): Promise<string> {
+  logger.info(`configureWifiProxy(udid=${udid}, isRealDevice=${isRealDevice}, proxyConfig=${JSON.stringify(proxyConfig)})`)
   try {
-    const host = proxy ? `${proxy.ip}:${proxy.port}` : ':0';
+    const isConfigValid = proxyConfig
+    && proxyConfig.ip
+    && proxyConfig.ip.trim().length > 0
+    && !isNaN(proxyConfig.port)
+    && proxyConfig.port > 0;
 
-    if (realDevice && proxy) {
-      await adbExecWithDevice(adb, udid, ['reverse', `tcp:${proxy.port}`, `tcp:${proxy.port}`]);
+    if (!isConfigValid) {
+      logger.warn(`Invalid proxy config: ${JSON.stringify(proxyConfig)}. Proxy will be disabled for udid ${udid}.`);
+    }
+
+    const host = isConfigValid ? `${proxyConfig.ip}:${proxyConfig.port}` : ':0';
+
+    if (isRealDevice && isConfigValid) {
+      await adbExecWithDevice(adb, udid, ['reverse', `tcp:${proxyConfig.port}`, `tcp:${proxyConfig.port}`]);
     }
 
     return await adbExecWithDevice(adb, udid, [
@@ -51,36 +77,66 @@ export async function configureWifiProxy(
   }
 }
 
-export async function getGlobalProxyValue(
+/**
+ * Retrieves the current global HTTP proxy settings from the target Android device via ADB.
+ * The function checks the 'http_proxy' setting in the 'global' namespace of the Android system settings.
+ *
+ * @param adb - The ADB instance established by Appium.
+ * @param udid - The Unique Device Identifier (UDID) of the Android device or emulator.
+ * @returns A Promise resolving to an object containing the IP and port of the proxy 
+ * ({ ip: string, port: number }), or undefined if no proxy is configured, 
+ * or if the configuration is invalid (e.g., malformed port).
+ * @throws {Error} Throws an error if the ADB command execution fails.
+ */
+export async function getCurrentWifiProxyConfig(
   adb: ADBInstance,
   udid: UDID
-): Promise<ProxyOptions> {
+): Promise<ProxyOptions | undefined> {
+  logger.info(`getCurrentWifiProxyConfig(udid=${udid})`);  
   try {
-    const proxy = await adbExecWithDevice(adb, udid, [
+    // Execute ADB command to get the current global HTTP proxy setting
+    const proxySettingsCommandResult = await adbExecWithDevice(adb, udid, [
       'shell',
       'settings',
       'get',
       'global',
-      'http_proxy'
-    ])
+      'http_proxy',
+    ]);
 
-    if(proxy == ":0" || proxy == "null") {
-      return {
-        port: 0
-      } as ProxyOptions
+    // ADB returns ":0" or "null" when the proxy is disabled.
+    if (!proxySettingsCommandResult || proxySettingsCommandResult === ':0' || proxySettingsCommandResult === 'null') {
+      logger.info(`No active proxy for udid ${udid}.`);
+      return undefined;
     } 
 
-    const [ip, portStr] = proxy.split(":");
+    // Ensure the format is IP:PORT (must contain at least one ':').
+    if (!proxySettingsCommandResult.includes(':')) {
+      logger.warn(`Invalid proxy settings format detected for udid ${udid}: '${proxySettingsCommandResult}'.`);
+      return undefined;
+    }
+
+    // Split the string into IP and port
+    const [ip, portStr] = proxySettingsCommandResult.split(':', 2);
     const port = Number(portStr);
 
-    return {
-      ip: ip,
-      port: port
-    } as ProxyOptions
+    // Validate IP and port values.
+    // IP should not be empty after trimming, and port must be a valid number greater than 0.
+    if (!ip.trim() || isNaN(port) || port <= 0) {
+        logger.warn(`Invalid proxy settings detected for udid ${udid}: (ip=${ip}, port=${port})`);
+        return undefined;
+    }
+
+    const proxyOptions: ProxyOptions = {
+        ip: ip.trim(),
+        port: port,
+    } as ProxyOptions;
+
+    logger.info(`Found active proxy for udid ${udid}: ${JSON.stringify(proxyOptions)}`);
+    return proxyOptions;
 
   } catch (error: any) {
-    throw new Error(`Error get global proxy value ${udid}: ${error.message}`);
-  }  
+    throw new Error(`Error getting wifi proxy settings for ${udid}: ${error.message}`);
+  }
 }
 
 /**

src/utils/proxy.ts

@@ -113,12 +113,12 @@ export async function setupProxyServer(
   deviceUDID: string,
   isRealDevice: boolean,
   certDirectory: string,
-  currentGlobalProxy?: ProxyOptions
+  currentWifiProxyConfig?: ProxyOptions
 ) {
   const certificatePath = prepareCertificate(sessionId, certDirectory);
   const port = await getPort();
   const _ip = isRealDevice ? 'localhost' : ip.address('public', 'ipv4');
-  const proxy = new Proxy({ deviceUDID, sessionId, certificatePath, port, ip: _ip, previousGlobalProxy: currentGlobalProxy });
+  const proxy = new Proxy({ deviceUDID, sessionId, certificatePath, port, ip: _ip, previousConfig: currentWifiProxyConfig });
   await proxy.start();
   if (!proxy.isStarted()) {
     throw new Error('Unable to start the proxy server');