Add network connectivity stress test for VPN resilience

.github/workflows/build-debug.yml

@@ -123,7 +123,7 @@ jobs:
           disk-size: 4096M
           heap-size: 512M
           disable-animations: true
-          script: ./gradlew connectedDebugAndroidTest --no-daemon
+          script: ./gradlew connectedDebugAndroidTest --no-daemon -Pandroid.testInstrumentationRunnerArguments.notClass=io.netbird.client.NetworkConnectivityStressTest
 
       - name: Upload test results
         if: always()

app/build.gradle.kts

@@ -45,6 +45,7 @@ android {
         versionName = rootProject.extra["appVersionName"] as String
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunnerArguments["timeout_msec"] = "3600000"
     }
 
     buildTypes {
@@ -80,6 +81,8 @@ dependencies {
     testImplementation(libs.junit)
     androidTestImplementation(libs.ext.junit)
     androidTestImplementation(libs.espresso.core)
+    androidTestImplementation(libs.uiautomator)
+    androidTestImplementation(libs.test.rules)
     implementation(libs.browser)  // Added for CustomTabsIntent
     implementation(libs.lottie)
     implementation(libs.zxing)

app/src/androidTest/README.md

@@ -0,0 +1,119 @@
+# Network Connectivity Stress Test
+
+Automated stress test that verifies the VPN recovers after real-world network disruptions.
+The test randomly picks disruption scenarios, applies them, waits a random amount of time,
+restores connectivity, then verifies VPN recovery by pinging a peer through the tunnel.
+
+## Prerequisites
+
+- The app must be **already logged in / authenticated**
+- A reachable VPN peer IP configured in `PING_TARGET` (default: `100.72.116.70`)
+- **Real device**: WiFi and mobile data (SIM card) available
+- **Emulator**: Copy auth token from `~/.emulator_console_auth_token` into `EMULATOR_AUTH_TOKEN` constant, or clear the file to disable auth
+
+## How to run
+
+```bash
+# 1. Build both APKs
+./gradlew assembleDebug assembleDebugAndroidTest
+
+# 2. Install them
+adb install -r -t app/build/outputs/apk/debug/app-debug.apk
+adb install -r -t app/build/outputs/apk/androidTest/debug/app-debug-androidTest.apk
+
+# 3. Run the test directly via adb
+adb shell am instrument -w -e class io.netbird.client.NetworkConnectivityStressTest \
+  io.netbird.client.test/androidx.test.runner.AndroidJUnitRunner
+```
+
+> **Note**: Do not use `./gradlew connectedAndroidTest` — Gradle's Unified Test Platform
+> may reinstall the APK mid-test, killing the process during long-running disruption cycles.
+
+## Watching live progress
+
+In a separate terminal:
+
+```bash
+adb logcat -s NBConnStressTest:D
+```
+
+## Useful helper commands
+
+```bash
+# Simulate battery mode (realistic power management: Doze, app standby)
+adb shell dumpsys battery unplug
+
+# Restore charging state after test
+adb shell dumpsys battery reset
+
+# Manually test airplane mode
+adb shell cmd connectivity airplane-mode enable
+adb shell cmd connectivity airplane-mode disable
+
+# Manually test WiFi/mobile data
+adb shell svc wifi disable
+adb shell svc wifi enable
+adb shell svc data disable
+adb shell svc data enable
+```
+
+## Configuration
+
+Constants at the top of `NetworkConnectivityStressTest.java`:
+
+| Constant | Default | Description |
+|----------|---------|-------------|
+| `PING_TARGET` | `100.72.116.70` | VPN peer IP to ping for connectivity verification |
+| `NUM_CYCLES` | `20` | Number of random disruption cycles |
+| `VPN_RECOVERY_TIMEOUT_SEC` | `90` | Max seconds to wait for VPN to recover per cycle |
+| `SETTLE_DELAY_SEC` | `5` | Seconds to wait after network change before checking |
+| `MAX_RANDOM_EXTRA_WAIT_SEC` | `15` | Max random extra wait to simulate real-world timing |
+| `PING_TIMEOUT_SEC` | `5` | Timeout for a single ping attempt |
+| `EMULATOR_AUTH_TOKEN` | `""` | Emulator console auth token (emulator only) |
+| `EMULATOR_CONSOLE_PORT` | `5554` | Emulator console telnet port (emulator only) |
+
+## Real Device Scenarios
+
+The test auto-detects real device vs emulator and picks from the appropriate scenario set.
+
+| # | Scenario | Disruption | Restore |
+|---|----------|-----------|---------|
+| 1 | WiFi→Mobile (leave office) | Disable WiFi | Enable WiFi |
+| 2 | Mobile→WiFi (at home) | Disable mobile data | Enable mobile data |
+| 3 | All networks lost (tunnel/elevator) | WiFi off + mobile off + airplane on | Airplane off + WiFi on + mobile on |
+| 4 | WiFi reconnect (switch network) | WiFi off → 2s → WiFi on | (already restored) |
+| 5 | WiFi flapping (unstable) | 3x: WiFi off 1.5s → WiFi on 1.5s | Enable WiFi |
+| 6 | Airplane mode toggle | Airplane on → 5s → airplane off | WiFi on + mobile on |
+| 7 | Mobile data flapping | 3x: mobile off 1s → mobile on 1s | Enable mobile |
+| 8 | Long outage (30s no network) | WiFi off + mobile off + airplane on → 30s | Airplane off + WiFi on + mobile on |
+| 9 | Sequential network loss | WiFi off → 3s → mobile off | Mobile on → 2s → WiFi on |
+| 10 | Airplane mode flapping | 2x: airplane on 3s → airplane off 3s | Airplane off + WiFi on + mobile on |
+
+## Emulator Scenarios
+
+Uses the emulator console (`telnet 10.0.2.2:5554`) to control the virtual network.
+Falls back to `iptables` rules if the console is not reachable.
+
+| # | Scenario | Disruption | Restore |
+|---|----------|-----------|---------|
+| 1 | Network disconnect | Full network cut | Network connect |
+| 2 | Long outage (30s) | Network cut → 30s wait | Network connect |
+| 3 | Network flapping (3x) | 3x: disconnect 1.5s → connect 1.5s | Network connect |
+| 4 | Extreme latency (10s delay) | 10s network delay | Delay 0 |
+| 5 | GPRS speed throttle | Speed → GSM | Speed → full |
+| 6 | Disconnect then slow reconnect | Disconnect → 5s → connect at GSM → 5s | Speed → full |
+| 7 | Flap then long disconnect (20s) | Disconnect → connect → disconnect → 20s | Network connect |
+| 8 | Latency flapping | 3x: 5s delay 2s → 0 delay 2s | Delay 0 |
+| 9 | Speed degradation cycle | HSDPA → 3s → EDGE → 3s → GSM → 5s | Speed → full |
+| 10 | Disconnect + degraded recovery | Disconnect → 10s → connect with 3s delay + EDGE → 5s | Delay 0 + speed full |
+
+## Test output
+
+The test prints a summary at the end:
+
+```text
+=== Results: 18/20 passed, 2 failed ===
+```
+
+If any cycle fails, the test fails with a message indicating how many cycles did not recover.
+Full details are in logcat under tag `NBConnStressTest`.