init

frontend/tests/test_path_patch.py

@@ -13,6 +13,7 @@ TOOLS_ROOT = FRONTEND_ROOT / "tools"
 sys.path.insert(0, str(TOOLS_ROOT))
 
 from _common import (  # noqa: E402
+    CORE_DYLIB,
     GROUP_DYLIBS,
     ORIGINAL_DEPLOYMENT_SEED,
     ORIGINAL_REPORTING_SEED,
@@ -101,6 +102,31 @@ class InitialDailyPathPatchTests(unittest.TestCase):
         with self.assertRaisesRegex(SystemExit, "unsupported Mach-O UUID"):
             patch_initial_daily_path(bytes(source), TEST_CHANNEL)
 
+    def test_fat_core_retargets_both_slices(self) -> None:
+        source = CORE_DYLIB.read_bytes()
+        self.assertEqual(source[:4], bytes.fromhex("cafebabe"))
+        patched, metadata = patch_initial_daily_path(
+            source, TEST_CHANNEL, label=CORE_DYLIB.name
+        )
+        self.assertEqual(metadata["container"], "fat")
+        expected = PATH_TEMPLATE.format(channel=TEST_CHANNEL).encode() + b"\x00"
+        self.assertEqual(metadata["path"], expected[:-1].decode())
+        slices = metadata["slices"]
+        self.assertEqual(len(slices), 2)
+        self.assertEqual(
+            {item["architecture"] for item in slices},
+            {"arm64", "arm64e"},
+        )
+        for item in slices:
+            slice_off = int(item["fat_slice_offset"])
+            cave = slice_off + int(item["path_file_offset"])
+            cfstring = slice_off + int(item["cfstring_file_offset"])
+            self.assertEqual(patched[cave : cave + len(expected)], expected)
+            self.assertEqual(
+                struct.unpack_from("<Q", patched, cfstring + 24)[0],
+                len(expected) - 1,
+            )
+
     def test_secondary_pack_manifest_records_native_path_patch(self) -> None:
         with tempfile.TemporaryDirectory() as temp:
             command = [