Android UI Verification

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.
• adb installed 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.xml

Search 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.png

Analytical Verification

Monitor the JS console logs in real-time to detect errors or log successes.

adb logcat -d | grep "ReactNativeJS" | tail -n 20

Cleanup

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 make grep verification easy.
• Fail Fast: If a uiautomator dump fails 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.