fix: one selection and one name per system

tests/test_system_selection.py

@@ -0,0 +1,75 @@
+"""One system, two spellings, one pack.
+
+stella2014 and stella2023 write atari_2600 where every other profile writes
+atari-2600. --system matched the spelling exactly and named the ZIP from
+it, so the two spellings built two different packs under one file name,
+the second replacing the first; --from-md5 --emulator X --standalone
+accepted a libretro-only core and named a standalone pack that was the
+libretro pack.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+import common  # noqa: E402
+import generate_pack as builder  # noqa: E402
+
+
+class SpellingsAgree(unittest.TestCase):
+    def test_both_spellings_select_the_same_profiles(self):
+        profiles = common.load_emulator_profiles(str(REPO_ROOT / "emulators"))
+        dashed = common.profiles_for_systems(profiles, ["atari-2600"])
+        underscored = common.profiles_for_systems(profiles, ["atari_2600"])
+        self.assertEqual(dashed, underscored)
+        self.assertIn("stella2014", dashed)
+        self.assertIn("gopher2600", dashed)
+
+    def test_the_pack_name_normalizes_the_spelling(self):
+        self.assertEqual(
+            builder._system_display_name("atari_2600"), builder._system_display_name("atari-2600")
+        )
+        self.assertEqual(builder._system_display_name("msxturboR"), builder._system_display_name("msxturbor"))
+
+
+class StandaloneNeedsAStandaloneBuild(unittest.TestCase):
+    def test_a_custom_pack_refuses_it_for_a_libretro_core(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            Path(tmp, "emulators").mkdir()
+            Path(tmp, "emulators", "handy.yml").write_text(
+                "emulator: Handy\ntype: libretro\nsystems: [atari-lynx]\nfiles:\n  - name: lynxboot.img\n"
+            )
+            common._emulator_profiles_cache.clear()
+            self.addCleanup(common._emulator_profiles_cache.clear)
+            db = {"files": {}, "indexes": {"by_md5": {}, "by_crc32": {}, "by_name": {}}}
+            result = builder.generate_md5_pack(
+                [("md5", "d8f1206299c48946e6ec5ef96d014eaa")], db, tmp, tmp,
+                emulator_name="handy", emulators_dir=str(Path(tmp, "emulators")), standalone=True,
+            )
+            self.assertIsNone(result)
+            self.assertEqual([p for p in os.listdir(tmp) if p.endswith(".zip")], [])
+
+
+class ADeclinedBuildIsAFailure(unittest.TestCase):
+    def test_a_target_that_removes_every_requested_system_exits_nonzero(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            proc = subprocess.run(
+                [sys.executable, "scripts/generate_pack.py", "--platform", "retroarch",
+                 "--system", "sony-playstation-2", "--target", "switch", "--offline",
+                 "--output-dir", tmp],
+                capture_output=True, text=True, cwd=str(REPO_ROOT), timeout=600, check=False,
+            )
+            self.assertNotEqual(proc.returncode, 0, proc.stdout + proc.stderr)
+            self.assertEqual([p for p in os.listdir(tmp) if p.endswith(".zip")], [])
+
+
+if __name__ == "__main__":
+    unittest.main()