refactor: one upstream name index for core lookups

tests/test_check_freshness.py

@@ -149,8 +149,8 @@ class CoreResolutionTests(unittest.TestCase):
 
     def test_index_maps_key_and_every_core_alias(self):
         index = cf.profile_name_index(self.PROFILES)
-        self.assertEqual(index["mednafen_psx"], "beetle_psx")
-        self.assertEqual(index["beetle_psx"], "beetle_psx")
+        self.assertEqual(index["mednafen_psx"], {"beetle_psx"})
+        self.assertEqual(index["beetle_psx"], {"beetle_psx"})
 
     def test_unresolved_honours_remove_cores_per_target(self):
         index = cf.profile_name_index(self.PROFILES)

tests/test_e2e.py

@@ -1659,8 +1659,8 @@ class TestE2E(unittest.TestCase):
         config = {
             "platform": "TestStandalone",
             "verification_mode": "existence",
-            "cores": ["test_emu"],
-            "standalone_cores": ["test_emu"],
+            "cores": ["test_sa"],
+            "standalone_cores": ["test_sa"],
             "systems": {
                 "console-a": {
                     "files": [
@@ -1680,7 +1680,7 @@ class TestE2E(unittest.TestCase):
         emu = {
             "emulator": "TestStandaloneEmu",
             "type": "standalone + libretro",
-            "cores": ["test_emu"],
+            "cores": ["test_sa"],
             "systems": ["console-a"],
             "files": [
                 {

tests/test_upstream_index.py

@@ -0,0 +1,51 @@
+"""One reverse index from upstream core names to profiles.
+
+Five copies broke ties differently. The target branch of
+resolve_platform_cores kept the last profile claiming a name, so the
+buildbot's `pcsx2` (the LRPS2 core) mapped to the standalone pcsx2 profile
+and a RetroArch target pack lost LRPS2's files.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+from common import (  # noqa: E402
+    preferred_profile,
+    resolve_platform_cores,
+    upstream_profile_index,
+)
+
+PROFILES = {
+    "lrps2": {"type": "libretro", "cores": ["lrps2", "pcsx2"]},
+    "pcsx2": {"type": "standalone", "cores": ["pcsx2"]},
+}
+
+
+class OneIndex(unittest.TestCase):
+    def test_target_keeps_every_claimant(self):
+        config = {"cores": "all_libretro"}
+        self.assertEqual(
+            resolve_platform_cores(config, PROFILES, target_cores={"pcsx2"}), {"lrps2"}
+        )
+
+    def test_platform_list_prefers_the_key(self):
+        config = {"cores": ["pcsx2"]}
+        self.assertEqual(resolve_platform_cores(config, PROFILES), {"pcsx2"})
+        self.assertEqual(preferred_profile(upstream_profile_index(PROFILES), "pcsx2"), "pcsx2")
+
+    def test_no_hand_made_index(self):
+        pattern = re.compile(r"(upstream_to_profile|core_to_profile)\[[^\]]+\]\s*=")
+        for path in sorted((REPO_ROOT / "scripts").rglob("*.py")):
+            with self.subTest(module=path.name):
+                self.assertIsNone(pattern.search(path.read_text(encoding="utf-8")))
+
+
+if __name__ == "__main__":
+    unittest.main()