Add mapping utils import boundary guard

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

CONTRIBUTING.md

@@ -172,6 +172,7 @@ This runs lint, format checks, compile checks, tests, and package build.
   - `tests/test_manager_transport_boundary.py` (manager transport boundary enforcement through shared request helpers),
   - `tests/test_mapping_keys_access_usage.py` (centralized key-iteration boundaries),
   - `tests/test_mapping_reader_usage.py` (shared mapping-read parser usage),
+  - `tests/test_mapping_utils_import_boundary.py` (mapping utility import boundary enforcement),
   - `tests/test_model_request_function_parse_boundary.py` (model-request function-level parse boundary enforcement between parsed wrappers and raw helpers),
   - `tests/test_model_request_function_transport_boundary.py` (model-request function-level transport boundary enforcement between parsed wrappers and raw helpers),
   - `tests/test_model_request_internal_reuse.py` (request-helper internal reuse of shared model request helper primitives),

tests/test_architecture_marker_usage.py

@@ -43,6 +43,7 @@
     "tests/test_manager_parse_boundary.py",
     "tests/test_manager_transport_boundary.py",
     "tests/test_mapping_reader_usage.py",
+    "tests/test_mapping_utils_import_boundary.py",
     "tests/test_mapping_keys_access_usage.py",
     "tests/test_model_request_function_parse_boundary.py",
     "tests/test_model_request_function_transport_boundary.py",

tests/test_mapping_utils_import_boundary.py

@@ -0,0 +1,42 @@
+import ast
+from pathlib import Path
+
+import pytest
+
+pytestmark = pytest.mark.architecture
+
+
+EXPECTED_MAPPING_UTILS_IMPORTERS = (
+    "hyperbrowser/client/managers/list_parsing_utils.py",
+    "hyperbrowser/client/managers/response_utils.py",
+    "hyperbrowser/tools/__init__.py",
+    "hyperbrowser/transport/base.py",
+    "tests/test_mapping_utils.py",
+)
+
+
+def _imports_mapping_utils(module_text: str) -> bool:
+    module_ast = ast.parse(module_text)
+    for node in module_ast.body:
+        if not isinstance(node, ast.ImportFrom):
+            continue
+        if node.module != "hyperbrowser.mapping_utils":
+            continue
+        return True
+    return False
+
+
+def test_mapping_utils_imports_are_centralized():
+    discovered_modules: list[str] = []
+
+    for module_path in sorted(Path("hyperbrowser").rglob("*.py")):
+        module_text = module_path.read_text(encoding="utf-8")
+        if _imports_mapping_utils(module_text):
+            discovered_modules.append(module_path.as_posix())
+
+    for module_path in sorted(Path("tests").glob("test_*.py")):
+        module_text = module_path.read_text(encoding="utf-8")
+        if _imports_mapping_utils(module_text):
+            discovered_modules.append(module_path.as_posix())
+
+    assert discovered_modules == list(EXPECTED_MAPPING_UTILS_IMPORTERS)