Device Discovery and Emulators

Testing on physical devices, simulators, and emulators proves real platform runtime behavior, permissions, and native bridge integration that cannot be replicated in unit or widget tests.

Target Discovery and Selection

• Query Available Targets: Run flutter devices to list connected devices, emulators, and desktop/browser engines.
• Select by Stable Identifier: When multiple devices are attached, always target a specific device using its stable device ID (-d <device-id>):

  flutter devices
  flutter run -d emulator-5554 --flavor staging

• Do NOT Reset User Devices or Casually Uninstall Applications:
  • Never issue factory reset, wipe, or erase commands on a developer's connected physical device or primary emulator. Prefer disposable test targets or ephemeral emulators.
  • Uninstalling an application (adb uninstall, xcrun simctl uninstall) or clearing application data (pm clear) destroys local databases, caches, preferences, and user-owned test data. Treat uninstallation as a destructive action requiring an explicit data-preservation and authorization decision rather than routine cleanup.
  • When clean state is authorized and verified to be safe:

    adb -s <id> uninstall com.example.app.staging
    xcrun simctl uninstall <id> com.example.app.staging

Capturing Platform Logs and Crashes

When an application fails to start or crashes during execution:

• Android: Capture the crash stack via flutter logs or direct logcat:

  adb -s <id> logcat -d -s flutter:V AndroidRuntime:E

• iOS: Inspect system and simulator logs via:

  xcrun simctl spawn <id> log stream --predicate 'process == "Runner"'

Exercising Platform States

Verify app behavior under real OS lifecycle transitions:

• Background and Resume: Simulate app backgrounding and foregrounding to verify state preservation and reconnection.
• Orientation Changes: Verify layout transitions when rotating between portrait and landscape modes.
• Permissions: Test both granted and denied states for camera, location, and notification permissions.