Restore behavioral render preset override coverage

tests/test_shim_config.py

@@ -1,4 +1,4 @@
-"""Marker polling configuration validation and environment precedence."""
+"""Engine opt-in, preset-selection behavior and polling configuration precedence."""
 import configparser
 import os
 from pathlib import Path
@@ -29,6 +29,7 @@ class ShimConfigTests(unittest.TestCase):
             ini.write_text('[Engine]\nEnabled = maybe\n')
             result = subprocess.run(cmd, env=env, text=True, capture_output=True)
             self.assertEqual(result.returncode, 2)
+
     def test_launcher_marker_poll_defaults_overrides_and_validation(self):
         with tempfile.TemporaryDirectory() as temporary:
             ini = Path(temporary) / 'd4r.ini'
@@ -46,7 +47,79 @@ class ShimConfigTests(unittest.TestCase):
                 ini.write_text(f'[Interop]\nMarkerPollUs = {value}\n')
                 result = subprocess.run(cmd, env=env, text=True, capture_output=True)
                 self.assertEqual(result.returncode, 2)
-                self.assertIn('MarkerPollUs must be a number of microseconds', result.stderr)
+
+
+class RenderPresetPolicyTests(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.directory = tempfile.TemporaryDirectory()
+        cls.addClassCleanup(cls.directory.cleanup)
+        cls.runner = Path(cls.directory.name) / 'render-presets'
+        source = r'''
+#include "d4r_render_presets.h"
+#include <cstdio>
+int main(int argc, char** argv) {
+    if (argc != 2) return 2;
+    const bool rr = argv[1][0] == '1';
+    unsigned int presets[6] = {21, 22, 23, 24, 25, 26};
+    if (rr) {
+        for (unsigned int& preset : presets) preset += 10;
+    }
+    const auto overrideValue = d4r_parse_render_preset_override(
+        std::getenv(d4r_render_preset_variable(rr)));
+    overrideValue.apply(presets);
+    for (unsigned int preset : presets) std::printf("%u ", preset);
+    std::puts("");
+}
+'''
+        subprocess.run(
+            ['c++', '-std=c++17', '-Wall', '-Wextra', '-Werror',
+             '-I', str(ROOT / 'tools'), '-x', 'c++', '-', '-o', str(cls.runner)],
+            input=source, text=True, capture_output=True, check=True)
+
+    def select(self, rr=False, **overrides):
+        env = dict(os.environ)
+        for name in ('D4R_DLSS_PRESET', 'D4R_RR_PRESET'):
+            env.pop(name, None)
+        env.update(overrides)
+        result = subprocess.run(
+            [str(self.runner), '1' if rr else '0'], env=env,
+            text=True, capture_output=True, check=True, timeout=5)
+        return [int(value) for value in result.stdout.split()]
+
+    def test_sr_models_override_every_quality_mode(self):
+        for value in (5, 11, 12, 13):
+            with self.subTest(preset=value):
+                self.assertEqual(
+                    self.select(D4R_DLSS_PRESET=str(value), D4R_RR_PRESET='4'),
+                    [value] * 6)
+
+    def test_rr_models_do_not_use_the_sr_override(self):
+        for value in (4, 5):
+            with self.subTest(preset=value):
+                self.assertEqual(
+                    self.select(rr=True, D4R_RR_PRESET=str(value), D4R_DLSS_PRESET='13'),
+                    [value] * 6)
+
+    def test_unset_override_preserves_quality_specific_game_presets(self):
+        for rr, foreign in ((False, 'D4R_RR_PRESET'), (True, 'D4R_DLSS_PRESET')):
+            with self.subTest(rr=rr):
+                expected = list(range(31, 37) if rr else range(21, 27))
+                self.assertEqual(self.select(rr=rr), expected)
+                self.assertEqual(self.select(rr=rr, **{foreign: '13'}), expected)
+
+    def test_empty_override_does_not_fall_back_to_the_other_feature(self):
+        self.assertEqual(
+            self.select(D4R_DLSS_PRESET='', D4R_RR_PRESET='5'),
+            list(range(21, 27)))
+        self.assertEqual(
+            self.select(rr=True, D4R_RR_PRESET='', D4R_DLSS_PRESET='13'),
+            list(range(31, 37)))
+
+    def test_explicit_default_preset_overrides_game_presets(self):
+        self.assertEqual(self.select(D4R_DLSS_PRESET='0'), [0] * 6)
+        self.assertEqual(self.select(rr=True, D4R_RR_PRESET='0'), [0] * 6)
+
 
 
 if __name__ == '__main__':