fix: keep the quasi88 group to the extension roms

tests/test_shared_groups.py

@@ -0,0 +1,65 @@
+"""A shared group adds files, never a second name for a native one.
+
+The quasi88 group declared N88SUB.ROM beside the disk.rom System.dat
+already names for nec-pc-88, same bytes: the RetroArch pack carried the
+2 KB ROM twice under quasi88/, and the group read as twelve required files
+where four did the work. Alternative names are aliases in the profile.
+"""
+
+from __future__ import annotations
+
+import sys
+import unittest
+from pathlib import Path
+
+import yaml
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+from common import list_registered_platforms, load_platform_config  # noqa: E402
+
+PLATFORMS = str(REPO_ROOT / "platforms")
+
+
+def _md5s(entry: dict) -> set[str]:
+    raw = entry.get("md5") or ""
+    values = raw if isinstance(raw, list) else str(raw).split(",")
+    return {v.strip().lower() for v in values if v and v.strip()}
+
+
+class SharedGroupsAddOnly(unittest.TestCase):
+    def test_no_shared_file_repeats_a_native_file_of_the_same_directory(self):
+        shared = yaml.safe_load((REPO_ROOT / "platforms" / "_shared.yml").read_text())
+        groups = shared.get("shared_groups") or {}
+        repeated = []
+        for platform in list_registered_platforms(PLATFORMS, include_archived=True):
+            config = load_platform_config(platform, PLATFORMS)
+            for system in config.get("systems", {}).values():
+                included = [
+                    fe for group in system.get("includes", []) for fe in groups.get(group, [])
+                ]
+                if not included:
+                    continue
+                group_keys = {
+                    (fe.get("name"), fe.get("destination", fe.get("name"))) for fe in included
+                }
+                native: dict[tuple[str, str], str] = {}
+                for fe in system.get("files", []):
+                    if (fe.get("name"), fe.get("destination", fe.get("name"))) in group_keys:
+                        continue
+                    dest = fe.get("destination") or fe.get("name", "")
+                    directory = dest.rsplit("/", 1)[0] if "/" in dest else ""
+                    for md5 in _md5s(fe):
+                        native.setdefault((directory, md5), fe.get("name", ""))
+                for fe in included:
+                    dest = fe.get("destination") or fe.get("name", "")
+                    directory = dest.rsplit("/", 1)[0] if "/" in dest else ""
+                    for md5 in _md5s(fe):
+                        other = native.get((directory, md5))
+                        if other and other.lower() != fe.get("name", "").lower():
+                            repeated.append(f"{platform}:{fe['name']} = {other}")
+        self.assertEqual(repeated, [])
+
+if __name__ == "__main__":
+    unittest.main()