native-compat: remove [api] and [dependencies] before horizon-mixins, as the launcher does (#364)

The launcher strips these launcher-only tables before horizon-mixins reads a
bundle's manifest (native_mods/api.rs). The check passed them through, so a
mod with a trait package (cpm, #317) failed with E_MANIFEST "unknown field api"
while players' launchers apply it. Mods with an API package are applied but
not compiled, as health already leaves them out.

Co-authored-by: Horizon agent <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>

scripts/native_compat.py

@@ -79,7 +79,27 @@ class Bundle:
         # As the launcher does for a mod built on another Horizon than it pins.
         toml = out / "horizon-mixin.toml"
         text = re.sub(r'horizon_revision\s*=\s*"[0-9a-f]{40}"', f'horizon_revision = "{revision}"', toml.read_text())
-        toml.write_text(text)
+        toml.write_text(strip_launcher_tables(text))
+
+
+# The tables only the launcher reads; it removes them before horizon-mixins sees the manifest (native_mods/api.rs).
+LAUNCHER_TABLES = ("api", "dependencies")
+
+
+def strip_launcher_tables(text):
+    """`text` without its [api] and [dependencies] tables (and their sub-tables), the rest unchanged."""
+    kept, skipping = [], False
+    for line in text.splitlines(keepends=True):
+        header = re.match(r'\s*\[\[?\s*([^\]]+?)\s*\]\]?\s*(#.*)?$', line)
+        if header:
+            skipping = header.group(1).split(".")[0].strip().strip('"\'') in LAUNCHER_TABLES
+        if not skipping:
+            kept.append(line)
+    stripped = "".join(kept)
+    want = {k: v for k, v in tomllib.loads(text).items() if k not in LAUNCHER_TABLES}
+    if tomllib.loads(stripped) != want:
+        sys.exit("horizon-mixin.toml: its [api] or [dependencies] table couldn't be removed line by line")
+    return stripped
 
 
 def download(url, sha256):
@@ -321,6 +341,10 @@ def check(args):
             failed.append(mod.id)
         if args.no_compile:
             continue
+        if mod.api:
+            # Its API package is staged by the launcher only (Bundle.api), as `health` leaves these out too.
+            print("- applies; it has a mod API package, which only the launcher builds, so it isn't compiled here.")
+            continue
         if compiles(stage):
             print(f"- applies and compiles with {len(popular) - len(refused)} popular mods.")
             continue

scripts/test_native_compat.py

@@ -0,0 +1,52 @@
+"""python3 -m unittest discover -s scripts -p 'test_*.py'"""
+import tomllib
+import unittest
+
+from native_compat import strip_launcher_tables
+
+MANIFEST = """[mod]
+id = "example"
+version = "1.0.0"
+
+[compatibility]
+horizon_revision = "0123456789abcdef0123456789abcdef01234567"
+
+# A trait-mod package.
+[api]
+path = "api"
+
+[dependencies]
+jei = { optional = true }
+
+[dependencies.ae2]
+optional = false
+
+[[module]]
+id = "runtime"
+file = "crates/horizon-client/src/game.rs"
+name = "example_mod"
+source = "runtime.rs"
+
+[[injection]]
+id = "frame"
+target = "horizon_client::game::native_hooks::Game<'_>::native_frame"
+helper = "frame.rs"
+"""
+
+
+class StripLauncherTables(unittest.TestCase):
+    def test_removes_only_the_launcher_tables(self):
+        stripped = tomllib.loads(strip_launcher_tables(MANIFEST))
+        original = tomllib.loads(MANIFEST)
+        self.assertNotIn("api", stripped)
+        self.assertNotIn("dependencies", stripped)
+        for key in ("mod", "compatibility", "module", "injection"):
+            self.assertEqual(stripped[key], original[key])
+
+    def test_a_manifest_without_them_is_unchanged(self):
+        plain = MANIFEST.split("# A trait-mod package.")[0] + MANIFEST.split('optional = false\n')[1]
+        self.assertEqual(strip_launcher_tables(plain), plain)
+
+
+if __name__ == "__main__":
+    unittest.main()