Android Emulator QA

Validate Android app flows in an emulator using adb for launch, input, UI-tree inspection, screenshots, and logs.

When to use

• QA a feature flow in an Android emulator.
• Reproduce UI bugs by driving navigation with adb input events.
• Capture screenshots and logcat output while testing.

Quick start

1. List emulators and pick a serial:
   • adb devices
2. Build and install the target variant:
   • ./gradlew :<module>:install<BuildVariant> --console=plain --quiet
   • If unsure about task names: ./gradlew tasks --all | rg install
3. Launch the app:
   • Resolve activity: adb -s <serial> shell cmd package resolve-activity --brief <package>
   • Start app: adb -s <serial> shell am start -n <package>/<activity>
4. Capture a screenshot for visual verification:
   • adb -s <serial> exec-out screencap -p > /tmp/emu.png

adb control commands

• Tap (use UI tree-derived coordinates):
  • adb -s <serial> shell input tap <x> <y>
• Swipe:
  • adb -s <serial> shell input swipe <x1> <y1> <x2> <y2>
  • Avoid edges (start ~150-200 px from left/right) to reduce accidental back gestures.
• Text:
  • adb -s <serial> shell input text "hello"
• Back:
  • adb -s <serial> shell input keyevent 4
• UI tree dump:
  • adb -s <serial> exec-out uiautomator dump /dev/tty

Coordinate picking (UI tree only)

Always compute tap coordinates from the UI tree, not screenshots.

1. Dump the UI tree to a step-specific file:
   • adb -s <serial> exec-out uiautomator dump /dev/tty > /tmp/ui-settings.xml
2. Find the target node and derive center coordinates (x y) from bounds:
   • Bounds format: bounds="[x1,y1][x2,y2]"
   • Helper script:
   • python3 <path-to-skill>/scripts/ui_pick.py /tmp/ui-settings.xml "Settings"
3. If the node is missing and there are scrollable elements:
   • swipe, re-dump, and re-search at least once before concluding the target is missing.
4. Tap the center:
   • adb -s <serial> shell input tap <x> <y>

UI tree skeleton (helper)

Use this helper to create a compact, readable overview before inspecting full XML.

1. Dump full UI tree:
   • adb -s <serial> exec-out uiautomator dump /dev/tty > /tmp/ui-full.xml
2. Generate summary:
   • python3 <path-to-skill>/scripts/ui_tree_summarize.py /tmp/ui-full.xml /tmp/ui-summary.txt
3. Review /tmp/ui-summary.txt to choose likely targets, then compute exact bounds from full XML.

Logs (logcat)

1. Clear logs:
   • adb -s <serial> logcat -c
2. Stream app process logs:
   • Resolve pid: adb -s <serial> shell pidof -s <package>
   • Stream: adb -s <serial> logcat --pid <pid>
3. Crash buffer only:
   • adb -s <serial> logcat -b crash
4. Save logs:
   • adb -s <serial> logcat -d > /tmp/logcat.txt

Package shortcuts

• List installed packages:
  • adb -s <serial> shell pm list packages
• Filter to your namespace:
  • adb -s <serial> shell pm list packages | rg <company_or_app_id>
• Confirm the activity resolves before launching:
  • adb -s <serial> shell cmd package resolve-activity --brief <package>