Create new dedicated tests/test_screenshot.py

tests/test_screenshot.py

@@ -0,0 +1,69 @@
+"""
+Graphical test for screenshot capture.
+
+This test focuses on screenshot capture for visual regression testing.
+
+Usage:
+    Desktop: ./tests/unittest.sh tests/test_screenshot.py
+    Device:  ./tests/unittest.sh tests/test_screenshot.py --ondevice
+"""
+
+import os
+import sys
+import unittest
+import mpos.ui
+from mpos import AppManager, DeviceInfo, capture_screenshot, wait_for_render
+
+
+class TestScreenshotCapture(unittest.TestCase):
+    """Test suite for screenshot capture."""
+
+    def setUp(self):
+        """Set up test fixtures before each test method."""
+        if sys.platform == "esp32":
+            self.screenshot_dir = "tests/screenshots"
+        else:
+            self.screenshot_dir = "../tests/screenshots"
+
+        try:
+            os.mkdir(self.screenshot_dir)
+        except OSError:
+            pass
+
+        self.hardware_id = DeviceInfo.hardware_id
+        print(f"Testing with hardware ID: {self.hardware_id}")
+
+    def tearDown(self):
+        """Clean up after each test method."""
+        try:
+            mpos.ui.back_screen()
+            wait_for_render(5)
+        except Exception:
+            pass
+
+    def test_capture_about_app_screenshot(self):
+        """Capture screenshot of the About app for regression testing."""
+        print("\n=== Starting About app screenshot test ===")
+
+        result = AppManager.start_app("com.micropythonos.about")
+        self.assertTrue(result, "Failed to start About app")
+
+        wait_for_render(iterations=15)
+
+        screenshot_path = f"{self.screenshot_dir}/about_app_{self.hardware_id}.raw"
+        print(f"\nCapturing screenshot to: {screenshot_path}")
+
+        try:
+            buffer = capture_screenshot(screenshot_path, width=320, height=240)
+            print(f"Screenshot captured: {len(buffer)} bytes")
+
+            stat = os.stat(screenshot_path)
+            self.assertTrue(
+                stat[6] > 0,
+                "Screenshot file is empty",
+            )
+            print(f"Screenshot file size: {stat[6]} bytes")
+        except Exception as exc:
+            self.fail(f"Failed to capture screenshot: {exc}")
+
+        print("\n=== About app screenshot test completed successfully ===")