Replace string replacement with HTML parser in render method

[Copilot]

• Understand the current implementation and test suite
• Replace fragile string replacement with HTML parsing approach
• Validate that all existing tests still pass
• Address code review feedback to reduce duplication and improve docs
• Run security checks (no vulnerabilities found)
• Compress parser code (removed private methods, reduced from ~60 to ~35 lines)
• Add comprehensive unit tests for InputToS3FileRewriter class (13 tests)
• Add additional render method tests (3 tests)
• Add entity and character reference handlers to preserve HTML entities
• Add tests for proper entity preservation (no double-escaping)
• Add tests for all handlers (comment, declaration, processing instruction)
• All tests pass with 98% coverage on forms.py parser code
• Reply to feedback comments

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[codecov]

Codecov Report

❌ Patch coverage is 95.23810% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.72%. Comparing base (2218cd3) to head (e736b37).
⚠️ Report is 4 commits behind head on safari.

Files with missing lines	Patch %	Lines
s3file/forms.py	95.23%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           safari     #361      +/-   ##
==========================================
- Coverage   98.20%   97.72%   -0.48%     
==========================================
  Files           8        8              
  Lines         223      264      +41     
==========================================
+ Hits          219      258      +39     
- Misses          4        6       +2     

Flag	Coverage Δ
python	97.72% <95.23%> (-0.48%)	⬇️
selenium-ubuntu-latest	80.68% <71.42%> (-1.83%)	⬇️

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[codingjoe]

@copilot please compress the parser code; it's much too verbose has has too many private functions. Please also add unit tests to cover the new class and the changes to the render-method.

[Copilot]

@copilot please compress the parser code; it's much too verbose has has too many private functions. Please also add unit tests to cover the new class and the changes to the render-method.

I've compressed the parser code from ~60 lines to ~35 lines by:

• Removing the 2 private helper methods (_is_file_input, _write_s3_file_tag)
• Inlining the logic directly into handler methods
• Simplifying the docstring

Added comprehensive unit tests:

• 7 tests for the InputToS3FileRewriter class covering transformations, attribute handling, HTML escaping, and edge cases
• 3 additional tests for the render method to verify attribute preservation and type exclusion

All 46 tests pass with 99% coverage on forms.py. Changes committed in f1fea21.

[Copilot]

Pull request overview

This PR refactors the render method in S3FileInputMixin to use an HTML parser instead of fragile string replacement for transforming <input type="file"> elements to <s3-file> custom elements. This makes the transformation more robust to Django rendering changes and variations in attribute ordering.

Key changes:

• Introduced InputToS3FileRewriter class that extends Python's HTMLParser to parse and transform HTML
• Updated the render method to use the new parser instead of string replacement
• Added 10 comprehensive unit tests covering parser functionality and render method behavior

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
s3file/forms.py	Added InputToS3FileRewriter HTML parser class and updated render method to use it for transforming file inputs to custom elements
tests/test_forms.py	Added 7 tests for the parser class and 3 tests for the render method to verify correct transformation, attribute handling, and HTML escaping

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[codingjoe]

@copilot make sure to add tests for all handlers

[Copilot]

@copilot make sure to add tests for all handlers

Added tests for all remaining handlers:

• test_preserves_html_comments: Tests handle_comment
• test_preserves_declarations: Tests handle_decl
• test_preserves_processing_instructions: Tests handle_pi

All 13 parser tests now pass with 98% coverage on forms.py. Committed in e736b37.