| name | uno-test-resize-app-window |
| description | Resize a running Uno Platform desktop app window on macOS for visual testing. Use when you need to verify responsive layout reflow, test breakpoints, or validate UI at different window sizes. Requires macOS Accessibility API access. |
| metadata | {"author":"https://github.com/VincentH-Net","version":"1.1","category":"testing","platform":"macOS"} |
Resize App Window on macOS for Visual Testing
Resize a running Uno Platform desktop app window programmatically using the macOS Accessibility API. Useful for verifying responsive layout behavior at specific widths without manual interaction.
Prerequisites
- macOS with Accessibility API access granted to the terminal/IDE
- A running Uno Platform desktop app (use
uno_app_start / uno_app_get_runtime_info first)
Usage
Run resize-window.sh with three arguments:
resize-window.sh APP_NAME WIDTH HEIGHT
APP_NAME — the app's process name (from uno_app_get_runtime_info → Process Name)WIDTH — target window width in pixelsHEIGHT — target window height in pixels
Common Test Widths
| Width | Columns (typical) | Use case |
|---|
| 500 | 1 | Mobile / narrow |
| 750 | 2 | Tablet / medium |
| 1024 | 3 | Desktop / wide |
| 1280 | 3-4 | Large desktop |
Workflow
- Start the app with
uno_app_start
- Confirm running with
uno_app_get_runtime_info (note Process Name)
- Take initial screenshot with
uno_app_get_screenshot
- Run
resize-window.sh "AppName" 500 800
- Take screenshot and verify layout reflow
- Repeat at additional widths as needed
- Restore original size when done
Troubleshooting
- "App not found": Verify the process name matches exactly (case-sensitive). Check with
uno_app_get_runtime_info.
- "Resize failed: -25211": Accessibility access not granted. The user must grant access in System Settings > Privacy & Security > Accessibility for the terminal app.
- Xcode
objc warnings in stderr: Harmless; ignore. The resize still succeeds.
Notes
- This technique uses the macOS Accessibility API (
AXUIElement), not AppleScript. AppleScript System Events requires separate assistive access and often fails for non-scriptable apps.
- The script targets the first window of the process. If the app has multiple windows, only the first is resized.
- Window position can also be set by replacing
kAXSizeAttribute with kAXPositionAttribute and using CGPoint instead of CGSize.
