[Buildroot] [PATCH 2/2] suport/runtime-test: extend flutter test to check rendering is happening

[Yann E. MORIN]

Commit 7f0af11cee31 (support/testing/tests/package/test_flutter.py: new
runtime test) added a simple test that just checked that the systemd
unit launching the application, was active.

It is perfectly possible, from a systemd perspective, that the unit is
active, while the application actually crashes.

Instead, what we need to check, is that the application does actually
render "something" we don't really care what, as long as we know it is
actually rendering, thus the graphical stack is working and the
aplication stack is running).

Extend the fultter runtime test to also check that the framebuffer is
modified by the application when it is running, similarly to what we do
in the weston test.

We drop the activation of the unit and start it manually, as we want to
check the state of the CRC before, during, and after the application
runs.

Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
Cc: Adam Duskett <aduskett at gmail.com>
---
 support/testing/tests/package/test_flutter.py | 33 ++++++++++++++++---
 .../flutter-gallery.service                   |  1 -
 2 files changed, 28 insertions(+), 6 deletions(-)
 delete mode 120000 support/testing/tests/package/test_flutter/overlay/etc/systemd/system/multi-user.target.wants/flutter-gallery.service

diff --git a/support/testing/tests/package/test_flutter.py b/support/testing/tests/package/test_flutter.py
index a3e98a43e5..6368bd1372 100644
--- a/support/testing/tests/package/test_flutter.py
+++ b/support/testing/tests/package/test_flutter.py
@@ -1,8 +1,11 @@
 import os
+import time
 import infra.basetest
 
+from ..graphics_base import GraphicsBase
 
-class TestFlutter(infra.basetest.BRTest):
+
+class TestFlutter(infra.basetest.BRTest, GraphicsBase):
     config = f"""
         BR2_aarch64=y
         BR2_TOOLCHAIN_EXTERNAL=y
@@ -48,7 +51,27 @@ class TestFlutter(infra.basetest.BRTest):
                      "-vnc", "none",
                      "-drive", f"file={img},if=virtio,format=raw"])
         self.emulator.login()
-        cmd = "systemctl is-active flutter-gallery"
-        output, exit_code = self.emulator.run(cmd, 10)
-        self.assertEqual(exit_code, 0)
-        self.assertEqual(output[0], "active")
+
+        # Get the CRC from the current ramebuffer
+        empty_crc = self.get_n_fb_crc(count=1)[0]
+
+        # Start the gallery Aapp. It can take a bit of time to start,
+        # so lets try a few times. 600 samples should cover about 10s
+        # @60Hz (although, the rendering could be much slower on slow
+        # machines)
+        self.assertRunOk("systemctl start flutter-gallery", timeout=10)
+        for i in range(600):
+            gallery_crc = self.get_n_fb_crc(count=1)[0]
+            if gallery_crc != empty_crc:
+                break
+            time.sleep(1)
+        self.assertNotEqual(gallery_crc, empty_crc, "gallery app did not render anything on screen")
+
+        # Stop the application, and check it restored the framebuffer content
+        self.assertRunOk("systemctl start flutter-gallery", timeout=10)
+        for i in range(600):
+            gallery_crc = self.get_n_fb_crc(count=1)[0]
+            if gallery_crc == empty_crc:
+                break
+            time.sleep(1)
+        self.assertEqual(gallery_crc, empty_crc, "gallery app did stop rendering")
diff --git a/support/testing/tests/package/test_flutter/overlay/etc/systemd/system/multi-user.target.wants/flutter-gallery.service b/support/testing/tests/package/test_flutter/overlay/etc/systemd/system/multi-user.target.wants/flutter-gallery.service
deleted file mode 120000
index 40993fb16c..0000000000
--- a/support/testing/tests/package/test_flutter/overlay/etc/systemd/system/multi-user.target.wants/flutter-gallery.service
+++ /dev/null
@@ -1 +0,0 @@
-../../../../usr/lib/systemd/system/flutter-gallery.service
\ No newline at end of file
-- 
2.25.1