Test dark mode too.

.github/workflows/python-app.yml

@@ -53,6 +53,17 @@ jobs:
           -s "-screen 0 1024x768x24 -fbdir $AUTOPKGTEST_TMP" \
           ./test_e2e.py
 
+    - name: Run GUI tests in dark mode
+      run: |
+        export AUTOPKGTEST_ARTIFACTS=`pwd`/artifacts/dark
+        mkdir -p $AUTOPKGTEST_ARTIFACTS
+        export AUTOPKGTEST_TMP=/tmp
+        export AUTOPKGTEST_BAMBAM_PROGRAM=./bambam.py
+        xvfb-run \
+          -e $AUTOPKGTEST_ARTIFACTS/xvfb-run.stderr \
+          -s "-screen 0 1024x768x24 -fbdir $AUTOPKGTEST_TMP" \
+          ./test_e2e.py --no-expect-light-mode -- --dark
+
     - name: Run GUI tests with deterministic sounds
       run: |
         export AUTOPKGTEST_ARTIFACTS=`pwd`/artifacts/deterministic

test_e2e.py

@@ -47,6 +47,7 @@ def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--expect-audio-output', action=argparse.BooleanOptionalAction, default=True)
     parser.add_argument('--expect-sounds', action=argparse.BooleanOptionalAction, default=True)
+    parser.add_argument('--expect-light-mode', action=argparse.BooleanOptionalAction, default=True)
     parser.add_argument('--sdl-audio-driver', default='disk')
     parser.add_argument('bambam_args', nargs='*')
     args = parser.parse_args()
@@ -65,8 +66,8 @@ def main():
         await_welcome_screen()
         send_keycodes('space')  # any keypress should do
         check_still_running(bambam)
-        await_blank_screen()
-        test_functionality(bambam, args.expect_sounds)
+        await_blank_screen(args.expect_light_mode)
+        test_functionality(bambam, args.expect_sounds, args.expect_light_mode)
         shut_bambam_down(bambam)
         logging.info('Waiting for game to exit cleanly.')
         exit_code = bambam.wait(timeout=_EXIT_SECONDS)
@@ -109,21 +110,27 @@ def await_welcome_screen():
         'after polling %d times every %f seconds.' % (attempt_count, sleep_delay))
 
 
-def await_blank_screen():
-    logging.info('Polling to observe a mostly-white screen (which means that welcome screen was cleared).')
+def await_blank_screen(expect_light: bool):
     attempt_count = 40
     sleep_delay = 0.25
+    if expect_light:
+        def check(c): return c >= 248
+        comment = 'mostly white screen'
+    else:
+        def check(c): return c < 2
+        comment = 'mostly black screen'
+    logging.info('Polling to observe a %s (which means that welcome screen was cleared).', comment)
     for attempt in range(attempt_count):
         current_average_color = get_average_color()
         logging.info('On attempt %d the average screen color was %s.', attempt, current_average_color)
-        if all(color_component >= 248 for color_component in current_average_color):
-            logging.info('Found mostly white screen, looks like bambam cleared the welcome screen OK.')
+        if all(check(color_component) for color_component in current_average_color):
+            logging.info('Found %s, looks like bambam cleared the welcome screen OK.', comment)
             take_screenshot('blank')
             return
         time.sleep(sleep_delay)
     raise Exception(
-        'Failed to see bambam clear the startup screen and display mostly-white background, '
-        'after polling %d times every %f seconds.' % (attempt_count, sleep_delay))
+        'Failed to see bambam clear the startup screen and display %s, '
+        'after polling %d times every %f seconds.' % (comment, attempt_count, sleep_delay))
 
 
 def check_still_running(bambam: subprocess.Popen):
@@ -132,7 +139,7 @@ def check_still_running(bambam: subprocess.Popen):
         raise Exception('Bambam unexpectedly exited with code %d' % bambam.returncode)
 
 
-def test_functionality(bambam: subprocess.Popen, try_unmute: bool):
+def test_functionality(bambam: subprocess.Popen, try_unmute: bool, expect_light: bool):
     check_still_running(bambam)
     logging.info('Exercising runtime mute.')
     send_keycodes('m', 'u')
@@ -150,15 +157,15 @@ def test_functionality(bambam: subprocess.Popen, try_unmute: bool):
         time.sleep(0.25)  # let the event propagate and bambam process it (leave some time for sound to play)
         # Do not bother checking screen if bambam crashed.
         check_still_running(bambam)
-        if is_screen_colorful_enough(attempt):
+        if is_screen_colorful_enough(attempt, expect_light):
             take_screenshot('success')
             return
     raise Exception('Failed to see a colorful enough screen after %d key presses.' % (attempt_count * 2))
 
 
-def is_screen_colorful_enough(attempt):
+def is_screen_colorful_enough(attempt, expect_light: bool):
     r, g, b = get_average_color()
-    if any(color < 10 for color in (r, g, b)):
+    if any(color < 30 for color in (r, g, b)):
         logging.info('On attempt %d the average screen color was too close to black: %d,%d,%d.', attempt, r, g, b)
         return False
     if any(color > 225 for color in (r, g, b)):