Improve port discovery of flutter server from device to support multiple flutter apps (#5)

* Refactor device port discovery for multiple flutter apps

* bump up version to beta.10

Author: sudharsan-selvaraj

android.conf.ts

@@ -9,9 +9,9 @@ export const config: WebdriverIO.Config = {
       platformName: 'Android',
       'appium:automationName': 'FlutterIntegration',
       'appium:orientation': 'PORTRAIT',
-      'appium:app': process.env.APP_PATH || join(process.cwd(), 'app-debug.apk'),
+      'appium:app':
+        process.env.APP_PATH || join(process.cwd(), 'app-debug.apk'),
       'appium:newCommandTimeout': 240,
-      'appium:skipLogcatCapture': true,
     },
   ],
 };

package-lock.json

@@ -5,7 +5,7 @@
     "appium",
     "flutter"
   ],
-  "version": "1.0.0-beta.9",
+  "version": "1.0.0-beta.10",
   "author": "",
   "license": "MIT License",
   "repository": {
@@ -76,15 +76,13 @@
     "@wdio/utils": "^8.38.0",
     "appium-adb": "^12.3.2",
     "appium-android-driver": "^9.6.2",
-    "appium-flutter-finder": "^0.2.0",
     "appium-ios-device": "^2.7.16",
     "appium-xcuitest-driver": "^7.16.2",
     "async-retry": "^1.3.3",
     "asyncbox": "^3.0.0",
     "axios": "^1.7.2",
     "bluebird": "^3.7.2",
     "chai": "^5.1.1",
-    "get-port": "^7.1.0",
     "lodash": "^4.17.21",
     "portscanner": "^2.2.0"
   }

package.json

@@ -3,6 +3,9 @@ import { log } from './logger';
 import type { InitialOpts } from '@appium/types';
 import { AppiumFlutterDriver } from './driver';
 import ADB from 'appium-adb';
+import { sleep } from 'asyncbox';
+import { fetchFlutterServerPort, getFreePort } from './utils';
+
 const setupNewAndroidDriver = async (
   ...args: any[]
 ): Promise<AndroidUiautomator2Driver> => {
@@ -19,18 +22,31 @@ export const startAndroidSession = async (
 ): Promise<[AndroidUiautomator2Driver, null]> => {
   log.info(`Starting an Android proxy session`);
   const androiddriver = await setupNewAndroidDriver(...args);
-
-  // the session starts without any apps
-  caps.flutterPort = caps.flutterPort || 8600;
-  log.info('Android session started', androiddriver);
-  await portForward(caps.flutterPort, caps.udid);
-  return [androiddriver, caps.flutterPort];
+  log.info('Looking for the port in where Flutter server is listening too...');
+  await sleep(2000);
+  const flutterServerPort = fetchFlutterServerPort(
+    (androiddriver.adb.logcat?.logs as [{ message: string }]) || [],
+  );
+  caps.flutterServerPort = await portForward(
+    caps.udid,
+    flutterServerPort,
+    caps.flutterServerPort,
+  );
+  return [androiddriver, caps.flutterServerPort];
 };
 
-const portForward = async (port: number, udid: string) => {
+const portForward = async (
+  udid: string,
+  devicePort: number,
+  systemPort?: number,
+) => {
+  if (!systemPort) {
+    systemPort = await getFreePort();
+  }
   let adb = new ADB();
   if (udid) adb.setDeviceId(udid);
-  await adb.forwardPort(port, 8888);
+  await adb.forwardPort(systemPort!, devicePort);
   const adbForwardList = await adb.getForwardList();
   log.info(`Port forwarding: ${JSON.stringify(adbForwardList)}`);
+  return systemPort;
 };

src/android.ts

@@ -23,9 +23,9 @@ import {
   ELEMENT_CACHE,
 } from './commands/element';
 
-import {  isFlutterDriverCommand } from './utils';
+import { isFlutterDriverCommand } from './utils';
 import { W3C_WEB_ELEMENT_IDENTIFIER } from '@appium/support/build/lib/util';
-import { waitForCondition } from 'asyncbox';
+import { sleep, waitForCondition } from 'asyncbox';
 import { log } from './logger';
 
 const DEFAULT_FLUTTER_SERVER_PORT = 8888;
@@ -177,7 +177,7 @@ export class AppiumFlutterDriver extends BaseDriver<FlutterDriverConstraints> {
   }
 
   async executeCommand(command: any, ...args: any) {
-    if(isFlutterDriverCommand(command)) {
+    if (isFlutterDriverCommand(command)) {
       return await super.executeCommand(command, ...args);
     }
     return await this.proxydriver.executeCommand(command as string, ...args);
@@ -202,16 +202,8 @@ export class AppiumFlutterDriver extends BaseDriver<FlutterDriverConstraints> {
       ...JSON.parse(JSON.stringify(args)),
     );
 
-    if (
-      this.proxydriver instanceof XCUITestDriver &&
-      !this.proxydriver.isRealDevice()
-    ) {
-      // @ts-ignore
-      this.flutterPort = DEFAULT_FLUTTER_SERVER_PORT;
-    }
-
     // HACK for eliminatin socket hang up by waiting 1 sec
-    await new Promise((r) => setTimeout(r, 1000));
+    await sleep(1000);
     // @ts-ignore
     console.log('PageSource', await this.proxydriver.getPageSource());
     // @ts-ignore

src/driver.ts

@@ -4,26 +4,32 @@ import XCUITestDriver from 'appium-xcuitest-driver';
 import type { InitialOpts } from '@appium/types';
 import { log } from './logger';
 import { DEVICE_CONNECTIONS_FACTORY } from './iProxy';
+import { sleep } from 'asyncbox';
+import { fetchFlutterServerPort, getFreePort } from './utils';
 
 const setupNewIOSDriver = async (...args: any[]): Promise<XCUITestDriver> => {
   const iosdriver = new XCUITestDriver({} as InitialOpts);
   await iosdriver.createSession(...args);
   return iosdriver;
 };
 
-async function portForward(iOSDriver: any, flutterPort: any, udid: any) {
-  // Need to do this for real device
-  if (
-    iOSDriver instanceof XCUITestDriver &&
-    iOSDriver.isRealDevice()
-  ) {
-    log.info(`Forwarding port ${flutterPort} to device ${udid}`);
-    await DEVICE_CONNECTIONS_FACTORY.requestConnection(udid, flutterPort, {
-      usePortForwarding: true,
-      devicePort: '8888',
-    });
+const portForward = async (
+  udid: string,
+  systemPort: number,
+  devicePort: any,
+) => {
+  if (!systemPort) {
+    systemPort = await getFreePort();
   }
-}
+  log.info(
+    `Forwarding port ${systemPort} to device port ${devicePort} ${udid}`,
+  );
+  await DEVICE_CONNECTIONS_FACTORY.requestConnection(udid, systemPort, {
+    usePortForwarding: true,
+    devicePort: devicePort,
+  });
+  return systemPort;
+};
 
 export const startIOSSession = async (
   flutterDriver: AppiumFlutterDriver,
@@ -32,10 +38,19 @@ export const startIOSSession = async (
 ): Promise<[XCUITestDriver, number]> => {
   log.info(`Starting an IOS proxy session`);
   const iOSDriver = await setupNewIOSDriver(...args);
-
-  // the session starts without any apps
-  caps.flutterPort = caps.flutterPort || 8600;
+  log.info('Looking for port Flutter server is listening too...');
+  await sleep(2000);
+  const flutterServerPort = fetchFlutterServerPort(iOSDriver.logs.syslog.logs);
+  if (iOSDriver.isRealDevice()) {
+    caps.flutterServerPort = await portForward(
+      iOSDriver.udid,
+      caps.flutterServerPort,
+      flutterServerPort,
+    );
+  } else {
+    //incase of emulator use the same port where the flutter server is running
+    caps.flutterServerPort = flutterServerPort;
+  }
   log.info('iOS session started', iOSDriver);
-  await portForward(iOSDriver, caps.flutterPort, caps.udid);
-  return [iOSDriver, caps.flutterPort];
+  return [iOSDriver, caps.flutterServerPort];
 };

src/iOS.ts

@@ -1,5 +1,12 @@
 import AndroidUiautomator2Driver from 'appium-uiautomator2-driver';
 import XCUITestDriver from 'appium-xcuitest-driver/build/lib/driver';
+import { log } from './logger';
+import { findAPortNotInUse } from 'portscanner';
+
+const FLUTTER_SERVER_START_MESSAGE = new RegExp(
+  /Appium flutter server is listening on port (\d+)/,
+);
+const DEVICE_PORT_RANGE = [9000, 9299];
 
 export async function getProxyDriver(
   strategy: string,
@@ -17,15 +24,57 @@ export async function getProxyDriver(
   }
 }
 
-
 export function isFlutterDriverCommand(command: string) {
-  return [
-          "createSession", "deleteSession", "getSession",
-          "getSessions", "findElement", "findElements",
-          "findElementFromElement", "findElementsFromElement", "click",
-          "getText", "setValue", "keys", "getName", "clear",
-          "elementSelected", "elementEnabled",
-          "getAttribute", "elementDisplayed", "execute"
-      ]
-      .indexOf(command) >= 0;
-}
+  return (
+    [
+      'createSession',
+      'deleteSession',
+      'getSession',
+      'getSessions',
+      'findElement',
+      'findElements',
+      'findElementFromElement',
+      'findElementsFromElement',
+      'click',
+      'getText',
+      'setValue',
+      'keys',
+      'getName',
+      'clear',
+      'elementSelected',
+      'elementEnabled',
+      'getAttribute',
+      'elementDisplayed',
+      'execute',
+    ].indexOf(command) >= 0
+  );
+}
+
+export function fetchFlutterServerPort(
+  deviceLogs: [{ message: string }],
+): number {
+  let port: number | undefined;
+  for (const line of deviceLogs.map((e) => e.message).reverse()) {
+    const match = line.match(FLUTTER_SERVER_START_MESSAGE);
+    if (match) {
+      log.info(`Found the server started log from device: ${line}`);
+      port = Number(match[1]);
+      break;
+    }
+  }
+  if (!port) {
+    throw new Error(
+      `Flutter server started message '${FLUTTER_SERVER_START_MESSAGE}' was not found in the device log. ` +
+        `Please make sure the application under test is configured properly according to ` +
+        `https://github.com/AppiumTestDistribution/appium-flutter-server and that it does not crash on startup.
+        Also make sure "appium:skipLogcatCapture" is not set to true in the desired capabilities. `,
+    );
+  }
+  log.info(`Extracted the port from the device logs: ${port}`);
+  return port;
+}
+
+export async function getFreePort() {
+  const [start, end] = DEVICE_PORT_RANGE;
+  return await findAPortNotInUse(start, end);
+}