fix: one agnostic substitute rule for pack and verify

tests/test_agnostic_substitute.py

@@ -0,0 +1,60 @@
+"""Pack, verify and manifest answer the same way for a filename-agnostic core.
+
+The pack alone renamed any PS2 image into a missing slot, even on an md5
+platform whose frontend then rejects it, and counted it OK; verify called
+the slot missing and the manifest omitted it.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+from validation import agnostic_substitute  # noqa: E402
+
+
+class AgnosticSubstitute(unittest.TestCase):
+    def test_only_the_platform_cores_answer(self):
+        with tempfile.TemporaryDirectory(dir=REPO_ROOT / "tmp") as tmp:
+            held = Path(tmp) / "ps2" / "scph39001.bin"
+            held.parent.mkdir()
+            held.write_bytes(b"x" * 16)
+            db = {
+                "files": {"a": {"path": str(held), "name": "scph39001.bin", "size": 16}},
+                "indexes": {"by_name": {"scph39001.bin": ["a"]}},
+            }
+            agnostic = {
+                "bios_mode": "agnostic",
+                "systems": ["sony-playstation-2"],
+                "files": [{"name": "scph39001.bin", "min_size": 8}],
+            }
+            self.assertEqual(
+                agnostic_substitute({}, "sony-playstation-2", db, {"pcsx2": agnostic}),
+                (str(held), f"{held.parent}/"),
+            )
+            self.assertIsNone(agnostic_substitute({}, "sony-playstation-2", db, {}))
+            self.assertIsNone(agnostic_substitute({}, "nintendo-nes", db, {"pcsx2": agnostic}))
+            self.assertIsNone(
+                agnostic_substitute({"md5": "0" * 32}, "sony-playstation-2", db, {"pcsx2": agnostic})
+            )
+
+    def test_every_reader_calls_it_behind_the_existence_gate(self):
+        builder = (REPO_ROOT / "scripts" / "generate_pack.py").read_text(encoding="utf-8")
+        verify = (REPO_ROOT / "scripts" / "verify.py").read_text(encoding="utf-8")
+        self.assertEqual(builder.count("agnostic_substitute(file_entry, sys_id"), 2)
+        self.assertEqual(verify.count("agnostic_substitute(file_entry, sys_id"), 1)
+        for source in (builder, verify):
+            for call in re.finditer(r"agnostic_substitute\(file_entry, sys_id", source):
+                window = source[max(0, call.start() - 300):call.start()]
+                self.assertIn("reads_file_contents", window)
+        self.assertNotIn('_emu_prof.get("bios_mode")', builder)
+
+
+if __name__ == "__main__":
+    unittest.main()