fix: normalize HTML responses for deterministic Django replay

[jy-tan]

Summary

Fixes non-deterministic HTML class attribute ordering that caused replay comparison failures in Django apps (e.g., django-unfold admin). Also fixes a critical bug in protobuf Value conversion that caused empty mock data during replay.

Context

The HTML class ordering issue was discovered during Django replay where templates (likely from django-unfold) rendered CSS classes in non-deterministic order. The protobuf bug was causing mock database rows to be empty during replay, leading to Django's StopIteration error when populating models.

Changes

HTML Normalization for Django Replay

• Add html_utils.py with normalize_html_class_ordering() to sort CSS classes alphabetically within class="..." attributes
• Consolidate CSRF token normalization into html_utils.py (deleted separate csrf_utils.py)
• Add normalize_html_body() and normalize_html_response() helpers to reduce code duplication
• Update middleware.py to use consolidated helpers for both RECORD and REPLAY modes
• Add 37 unit tests for HTML normalization

Protobuf Utils Refactor

• Extract shared value_to_python() and struct_to_dict() into new protobuf_utils.py
• Fix bug where hasattr() was incorrectly used to check protobuf oneof fields (always returns True for protobuf attributes, causing all values to return None)
• Properly handle: Python native types, Google protobuf Value (WhichOneof), and betterproto Value (is_set)
• Remove ~130 lines of duplicated code from communicator.py and types.py
• Add 27 unit tests for protobuf conversion

[cubic-dev-ai]

1 issue found across 8 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="tests/unit/test_html_utils.py">

<violation number="1" location="tests/unit/test_html_utils.py:286">
P2: Deleting `response.content` on a MagicMock with `spec=["get"]` raises `AttributeError`, so this test will fail before it runs. The mock already lacks a `content` attribute; removing the delete fixes the test.</violation>
</file>

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