Android UI Verification Skill
This skill provides a systematic approach to testing React Native applications on an Android emulator using ADB commands. It allows for autonomous interaction, state verification, and visual regression checking.
When to Use
- Verifying UI changes in React Native or Native Android apps.
- Autonomous debugging of layout issues or interaction bugs.
- Ensuring feature functionality when manual testing is too slow.
- Capturing automated screenshots for PR documentation.
🛠 Prerequisites
- Android Emulator running.
adbinstalled and in PATH.- Application in debug mode for logcat access.
🚀 Workflow
1. Device Calibration
Before interacting, always verify the screen resolution to ensure tap coordinates are accurate.
adb shell wm size*Note: Layouts are often scaled. Use the physical size returned as the base for coordinate calculations.*
2. UI Inspection (State Discovery)
Use the uiautomator dump to find the exact bounds of UI elements (buttons, inputs).
adb shell uiautomator dump /sdcard/view.xml && adb pull /sdcard/view.xml ./artifacts/view.xmlSearch the view.xml for text, content-desc, or resource-id. The bounds attribute [x1,y1][x2,y2] defines the clickable area.
3. Interaction Commands
- Tap:
adb shell input tap <x> <y>(Use the center of the element bounds). - Swipe:
adb shell input swipe <x1> <y1> <x2> <y2> <duration_ms>(Used for scrolling). - Text Input:
adb shell input text "<message>"(Note: Limited support for special characters). - Key Events:
adb shell input keyevent <code_id>(e.g., 66 for Enter).
4. Verification & Reporting
Visual Verification
Capture a screenshot after interaction to confirm UI changes.
adb shell screencap -p /sdcard/screen.png && adb pull /sdcard/screen.png ./artifacts/test_result.pngAnalytical Verification
Monitor the JS console logs in real-time to detect errors or log successes.
adb logcat -d | grep "ReactNativeJS" | tail -n 20Cleanup
Always store generated files in the artifacts/ folder to satisfy project organization rules.
💡 Best Practices
- Wait for Animations: Always add a short sleep (e.g., 1-2s) between interaction and verification.
- Center Taps: Calculate the arithmetic mean of
[x1,y1][x2,y2]for the most reliable tap target. - Log Markers: Use distinct log messages in the code (e.g.,
✅ Action Successful) to makegrepverification easy. - Fail Fast: If a
uiautomator dumpfails or doesn't find the expected text, stop and troubleshoot rather than blind-tapping.
Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.