fix: diff the truth against the platform's own list

scripts/common.py

@@ -201,6 +201,33 @@ def load_platform_config(platform_name: str, platforms_dir: str = "platforms") -
     return config
 
 
+def native_layer(config: dict | None) -> dict | None:
+    """The platform config without what we add to it.
+
+    A shared group's files join the config for the pack, but the platform's
+    file does not carry them: counted kept, they were written into
+    libretro's System.dat (N88EXT0-3.ROM) as if libretro declared them. What
+    a core needs from a group reaches the export through the truth, as an
+    addition the format's gates apply to. A scraper's mirror of an entry
+    under another system (RomM's tg16 firmware under turbografx-cd), and a
+    file our scraper adds from the cores' source (Dolphin's DSP ROMs in
+    RetroArch's config), are not in the platform's file either.
+    """
+    if config is None:
+        return None
+    systems = {
+        sys_id: {
+            **system,
+            "files": [
+                f for f in system.get("files", [])
+                if not ({"shared_group", "mirror_of", "curated"} & f.keys())
+            ],
+        }
+        for sys_id, system in config.get("systems", {}).items()
+    }
+    return {**config, "systems": systems}
+
+
 def load_data_dir_registry(platforms_dir: str = "platforms") -> dict:
     """Load the data directory registry from _data_dirs.yml."""
     registry_path = os.path.join(platforms_dir, "_data_dirs.yml")

scripts/diff_truth.py

@@ -16,7 +16,13 @@ import os
 import sys
 
 sys.path.insert(0, os.path.dirname(__file__))
-from common import list_registered_platforms, load_platform_config, require_yaml, yaml_load
+from common import (
+    list_registered_platforms,
+    load_platform_config,
+    native_layer,
+    require_yaml,
+    yaml_load,
+)
 from truth import diff_platform_truth
 
 yaml = require_yaml()
@@ -188,7 +194,9 @@ def main() -> None:
             continue
 
         try:
-            scraped = load_platform_config(platform, args.platforms_dir)
+            # What the platform's own file declares: our shared groups,
+            # mirrors and curated additions are not theirs to be credited.
+            scraped = native_layer(load_platform_config(platform, args.platforms_dir))
         except FileNotFoundError:
             print(f"skip {platform}: no scraped config", file=sys.stderr)
             continue

scripts/export_native.py

@@ -26,7 +26,7 @@ from pathlib import Path
 sys.path.insert(0, str(Path(__file__).resolve().parent))
 
 from artifacts import file_lock, write_bytes_atomic, write_text_atomic
-from common import list_registered_platforms, load_platform_config, yaml_load
+from common import list_registered_platforms, load_platform_config, native_layer, yaml_load
 from exporter import discover_exporters
 from exporter.baseline import HASH_FIELDS, _hash_values, _single_size, build_native_model
 
@@ -206,34 +206,7 @@ def load_inputs(
         scraped = load_platform_config(platform, platforms_dir)
     except (FileNotFoundError, OSError):
         scraped = None
-    return truth, _native_layer(scraped)
-
-
-def _native_layer(config: dict | None) -> dict | None:
-    """The platform config without what we add to it.
-
-    A shared group's files join the config for the pack, but the platform's
-    file does not carry them: counted kept, they were written into
-    libretro's System.dat (N88EXT0-3.ROM) as if libretro declared them. What
-    a core needs from a group reaches the export through the truth, as an
-    addition the format's gates apply to. A scraper's mirror of an entry
-    under another system (RomM's tg16 firmware under turbografx-cd), and a
-    file our scraper adds from the cores' source (Dolphin's DSP ROMs in
-    RetroArch's config), are not in the platform's file either.
-    """
-    if config is None:
-        return None
-    systems = {
-        sys_id: {
-            **system,
-            "files": [
-                f for f in system.get("files", [])
-                if not ({"shared_group", "mirror_of", "curated"} & f.keys())
-            ],
-        }
-        for sys_id, system in config.get("systems", {}).items()
-    }
-    return {**config, "systems": systems}
+    return truth, native_layer(scraped)
 
 
 def refresh_cache(

scripts/generate_site.py

@@ -38,6 +38,7 @@ from common import (
     load_database,
     load_emulator_profiles,
     load_provenance_snapshots,
+    native_layer,
     require_yaml,
     resolution_is_hash_exact,
     resolve_local_file,
@@ -2742,7 +2743,7 @@ def generate_gap_analysis(
         truth_data = generate_platform_truth(
             pname, cov["config"], (registry or {}).get(pname, {}), profiles, db
         )
-        s = diff_platform_truth(truth_data, cov["config"])["summary"]
+        s = diff_platform_truth(truth_data, native_layer(cov["config"]))["summary"]
         if s["systems_compared"] == 0:
             div_rows.append(
                 f"| [{cov['platform']}](platforms/{pname}.md) | - | - | - | - |"