dev: add deterministic demo dataset

backend/tests/test_frontend_shell.py

@@ -1,3 +1,4 @@
+import re
 import unittest
 from pathlib import Path
 from unittest.mock import patch
@@ -157,6 +158,31 @@ class FrontendShellTests(unittest.TestCase):
             self.assertIn(value, response.text)
         self.assertNotIn("Live layout and telemetry data are not", response.text)
 
+    def test_map_script_dom_contract_matches_rendered_page(self):
+        self.authenticate()
+        response = self.client.get("/monitoring/map")
+        javascript = (STATIC_ROOT / "mine-map.js").read_text(encoding="utf-8")
+        declared_ids = re.search(
+            r"const ids = \[(.*?)\];",
+            javascript,
+            re.DOTALL,
+        )
+        self.assertIsNotNone(declared_ids)
+        required = set(
+            re.findall(
+                r'"([A-Za-z][A-Za-z0-9]+)"',
+                declared_ids.group(1),
+            )
+        )
+        required.update(
+            re.findall(
+                r'document\.getElementById\("([^"]+)"\)',
+                javascript,
+            )
+        )
+        rendered = set(re.findall(r'\bid="([^"]+)"', response.text))
+        self.assertEqual(required - rendered, set())
+
     def test_data_views_include_all_request_states(self):
         self.authenticate()
         for path in ("/operations/repairs", "/assets/miners"):