migration: preserve frontend shell pages and styles

app/tests/test_preservation_slice_ladder_rotation.py

@@ -5,6 +5,13 @@ import hashlib
 import unittest
 from pathlib import Path
 
+from tests.preservation_helpers import (
+    ORIGINAL_STATIC,
+    assert_moved_asset_matches,
+    assert_page_prefix_matches,
+    reassembled_frontend_runtime,
+)
+
 
 APP_ROOT = Path(__file__).resolve().parents[1]
 ORIGINAL_ROOT = APP_ROOT.parent
@@ -73,19 +80,17 @@ class LadderRotationSliceSourceEquivalenceTests(unittest.TestCase):
         )
 
     def test_api_and_frontend_assets_are_unchanged(self) -> None:
-        for relative in (
-            "config/api.config.json",
-            "static/index.html",
-            "static/app.js",
-            "static/styles.css",
-            "static/pages/ladder/page.js",
-            "static/pages/rotation/page.js",
-        ):
-            self.assertEqual(
-                sha256(APP_ROOT / relative),
-                sha256(ORIGINAL_ROOT / relative),
-                relative,
-            )
+        self.assertEqual(
+            sha256(APP_ROOT / "config/api.config.json"),
+            sha256(ORIGINAL_ROOT / "config/api.config.json"),
+        )
+        self.assertEqual(
+            reassembled_frontend_runtime(),
+            (ORIGINAL_STATIC / "app.js").read_text(encoding="utf-8"),
+        )
+        assert_moved_asset_matches(self, "styles.css", "styles/styles.css")
+        for page in ("pages/ladder/page.js", "pages/rotation/page.js"):
+            assert_page_prefix_matches(self, page)
 
 
 if __name__ == "__main__":