fix: name a target only where it narrows the pack

scripts/common.py

@@ -511,6 +511,17 @@ def _target_alias_index(targets: dict, overrides: dict) -> dict[str, str]:
     return alias_index
 
 
+def platform_files_target(platform: str, target: str, platforms_dir: str = "platforms") -> bool:
+    """Whether the platform's targets file knows this target, by any alias."""
+    targets_dir = os.path.join(platforms_dir, "targets")
+    target_file = os.path.join(targets_dir, f"{platform}.yml")
+    if not os.path.exists(target_file):
+        return False
+    with open(target_file) as f:
+        targets = (yaml_load(f) or {}).get("targets", {})
+    return target in _target_alias_index(targets, _target_overrides(platform, targets_dir))
+
+
 def canonical_target_name(
     platforms: list[str], target: str, platforms_dir: str = "platforms"
 ) -> str:

scripts/generate_pack.py

@@ -53,6 +53,7 @@ from common import (
     list_emulator_profiles,
     list_platform_system_ids,
     canonical_target_name,
+    platform_files_target,
     list_registered_platforms,
     list_system_ids,
     load_data_dir_registry,
@@ -227,9 +228,11 @@ def _platform_target(
     Named once for the whole run, a target two platforms file differently
     (rpi4: Batocera's bcm2711, Recalbox's rpi4_64) kept the typed name under
     --all and took the platform's own under --platform, so --verify-packs
-    looked for a pack the --all build had named otherwise.
+    looked for a pack the --all build had named otherwise. A platform that
+    does not file the target is packed whole under --all, and its name
+    claims no narrowing: BizHawk_..._Switch_BIOS_Pack.zip was the full pack.
     """
-    if not target:
+    if not target or not platform_files_target(platform_name, target, platforms_dir):
         return None
     return canonical_target_name([platform_name], target, platforms_dir)
 

tests/test_target_verify.py

@@ -35,5 +35,21 @@ class CheckReadsTheTargetLikeTheBuild(unittest.TestCase):
         self.assertTrue(cores)
 
 
+class ANameClaimsOnlyANarrowingThatHappened(unittest.TestCase):
+    """--all --target switch packed BizHawk and MiSTer whole, and named them
+    BizHawk_..._Switch_BIOS_Pack.zip with a README saying 'cores available
+    on switch'."""
+
+    def test_a_platform_without_the_target_is_named_plainly(self):
+        from generate_pack import _narrowings, _platform_target
+
+        platforms = str(REPO_ROOT / "platforms")
+        self.assertIsNone(_platform_target("bizhawk", "switch", platforms))
+        self.assertEqual(_narrowings("full", None, None, False, False), [])
+        self.assertEqual(
+            _platform_target("retroarch", "nx", platforms), "nintendo-switch"
+        )
+
+
 if __name__ == "__main__":
     unittest.main()