Only apply blink-settings on Qt 15.5.2

Turns out Qt 5.15.{0,1} also needs `--force-dark-mode`. This commit
fixes it to only use the blink-setting on Qt 5.15.2 and up. It also
parameterizes the tests better to test that the settings work on their
respective Qt versions.

5 files changed, 26 insertions, 16 deletions

diff --git a/qutebrowser/browser/webengine/darkmode.py b/qutebrowser/browser/webengine/darkmode.py
index 5ae079392..86b7f8c59 100644
--- a/qutebrowser/browser/webengine/darkmode.py
+++ b/qutebrowser/browser/webengine/darkmode.py
@@ -264,8 +264,10 @@ def _variant() -> Variant:
 
 def settings() -> Iterator[Tuple[str, str]]:
     """Get necessary blink settings to configure dark mode for QtWebEngine."""
-    if (qtutils.version_check('5.15', compiled=False) and
+    if (qtutils.version_check('5.15.2', compiled=False) and
             config.val.colors.webpage.prefers_color_scheme_dark):
+        # In future versions of 'blink', (> Qt 5.15.2) the enumeration has
+        # changed and this will need to be set to '0' instead.
         yield "preferredColorScheme", "1"
 
     if not config.val.colors.webpage.darkmode.enabled:
diff --git a/qutebrowser/config/qtargs.py b/qutebrowser/config/qtargs.py
index 663296bbc..2136f7e7f 100644
--- a/qutebrowser/config/qtargs.py
+++ b/qutebrowser/config/qtargs.py
@@ -204,10 +204,10 @@ def _qtwebengine_settings_args() -> Iterator[str]:
     }
 
     if (qtutils.version_check('5.14', compiled=False) and
-            not qtutils.version_check('5.15', compiled=False)):
-        # In Qt 5.14, `--force-dark-mode` is used to set the preferred
-        # colorscheme. In Qt 5.15, this is handled by a blink-setting
-        # instead.
+            not qtutils.version_check('5.15.2', compiled=False)):
+        # In Qt 5.14 to 5.15.1, `--force-dark-mode` is used to set the
+        # preferred colorscheme. In Qt 5.15.2, this is handled by a
+        # blink-setting instead.
         settings['colors.webpage.prefers_color_scheme_dark'] = {
             True: '--force-dark-mode',
             False: None,
diff --git a/tests/helpers/utils.py b/tests/helpers/utils.py
index 3b5ee0ab6..2c275bf15 100644
--- a/tests/helpers/utils.py
+++ b/tests/helpers/utils.py
@@ -44,9 +44,6 @@ ON_CI = 'CI' in os.environ
 qt514 = pytest.mark.skipif(
     not qtutils.version_check('5.14'), reason="Needs Qt 5.14 or newer")
 
-qt515 = pytest.mark.skipif(
-    not qtutils.version_check('5.15'), reason="Needs Qt 5.15 or newer")
-
 
 class PartialCompareOutcome:
 
diff --git a/tests/unit/browser/webengine/test_darkmode.py b/tests/unit/browser/webengine/test_darkmode.py
index 0c39cf95c..cd84526c3 100644
--- a/tests/unit/browser/webengine/test_darkmode.py
+++ b/tests/unit/browser/webengine/test_darkmode.py
@@ -32,16 +32,23 @@ def patch_backend(monkeypatch):
     monkeypatch.setattr(objects, 'backend', usertypes.Backend.QtWebEngine)
 
 
-@pytest.mark.parametrize('enabled, expected', [
+@pytest.mark.parametrize('qversion, enabled, expected', [
     # Disabled or nothing set
-    (False, []),
+    ("5.14", False, []),
+    ("5.15.0", False, []),
+    ("5.15.1", False, []),
+    ("5.15.2", False, []),
 
     # Enabled in configuration
-    (True, [("preferredColorScheme", "1")]),
+    ("5.14", True, []),
+    ("5.15.0", True, []),
+    ("5.15.1", True, []),
+    ("5.15.2", True, [("preferredColorScheme", "1")]),
 ])
-@utils.qt515
-def test_colorscheme(config_stub, monkeypatch, enabled, expected):
-    config_stub.set_obj('colors.webpage.prefers_color_scheme_dark', enabled)
+@utils.qt514
+def test_colorscheme(config_stub, monkeypatch, qversion, enabled, expected):
+    monkeypatch.setattr(darkmode.qtutils, 'qVersion', lambda: qversion)
+    config_stub.val.colors.webpage.prefers_color_scheme_dark = enabled
     assert list(darkmode.settings()) == expected
 
 
diff --git a/tests/unit/config/test_qtargs.py b/tests/unit/config/test_qtargs.py
index d26a8ab50..8ff5b95d3 100644
--- a/tests/unit/config/test_qtargs.py
+++ b/tests/unit/config/test_qtargs.py
@@ -292,10 +292,14 @@ class TestQtArgs:
     @pytest.mark.parametrize('dark, qt_version, added', [
         (True, "5.13", False),
         (True, "5.14", True),
-        (True, "5.15", False),
+        (True, "5.15.0", True),
+        (True, "5.15.1", True),
+        (True, "5.15.2", False),
         (False, "5.13", False),
         (False, "5.14", False),
-        (False, "5.15", False),
+        (False, "5.15.0", False),
+        (False, "5.15.1", False),
+        (False, "5.15.2", False),
     ])
     @utils.qt514
     def test_prefers_color_scheme_dark(self, config_stub, monkeypatch, parser,